Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

Diversity of freshwater hydrozoans from Neotropical region:

an annotated inventory of species

María I. Deserti1* https://orcid.org/0000-0003-4809-3608

Sergio N. Stampar2 https://orcid.org/0000-0003-3075-2492

Fabián H. Acuña1,3 https://orcid.org/0000-0002-9782-1619

1. Instituto de Investigaciones Marinas y Costeras (IIMyC) CONICET; Facultad de Ciencias Exactas y Naturales,

Universidad Nacional de Mar Del Plata, Mar Del Plata, Argentina; desertiirene@gmail.com (Correspondence).

2. Laboratório de Evolução e Diversidade Aquática (LEDA), Departamento de Ciências Biológicas, Faculdade de

Ciências, Universidade Estadual Paulista, Bauru SP, Brazil; sergio.stampar@unesp.br

3. Estación Científica Coiba (Coiba-AIP), calle Gustavo Lara, Edificio 145B, Clayton, Panamá, República de Panamá;

facuna@mdp.edu.ar

Received 20-X-2022. Corrected 12-VII-2023. Accepted 17-VII-2023.

ABSTRACT

Introduction: Worldwide, six genera of the class Hydrozoa are recognized in continental waters: the cosmopoli-

tan Hydra, the colonial Cordylophora and Pachycordyle, the medusae Craspedacusta and Limnocnida and the little

polyp Calpasoma. Even though interest in cnidarians has grown in recent years, those restricted to freshwater

continue to be relegated and there is even little published information on the ubiquity of certain species. In the

Neotropical region, knowledge about its distribution is still very scarce.

Methods: We reviewed the global literature on the subject and different online database platforms, presenting

in this work a nomenclator, including discussions of the status of some species and provide the most recent

identification key.

Results: This analysis reveals that in 15 countries corresponding to the Neotropical region, the finding of fresh-

water hydrozoans has been reported. Panama, Brazil and Argentina are the countries with the highest number

of reports.

Conclusions: The heterogenity of environments where these genera have been found (from the Strait of Magellan

to Mexico) offers a clear vision of their wide distribution and great adaptability to different environments. This

study evidence the knowledge gap that still exists about the Neotropical freshwater hidrozoans and the impor-

tance of systematizing the current information about their distribution, biology and ecology, especially for those

species considered invasive.

Key words: Cnidaria; inland waters; Neotropical region; freshwater species.

RESUMEN

Diversidad de hidrozoos de agua dulce de la región Neotropical: un inventario comentado de especies

Introducción: A nivel mundial, se reconocen seis géneros de hidrozoos de agua dulce: la cosmopolita Hydra, los

pólipos coloniales Cordylophora y Pachycordyle, las medusas Craspedacusta y Limnocnida y el pequeño pólipo

Calpasoma. A pesar de que el interés por los cnidarios ha crecido en los últimos años, los grupos restringidos a

agua dulce siguen relegados, hay poca información sobre la ubicuidad de ciertas especies, o los datos no han sido

publicados oficialmente. En la región Neotropical el conocimiento de la distribución de este grupo zoológico aún

continúa siendo escaso.

https://doi.org/10.15517/rev.biol.trop..v71iS3.56470

SUPPLEMENT

2Revista de Biología Tropical, ISSN: 2215-2075 Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

INTRODUCTION

Global diversity of inland waters cnidar-

ians, excepting for Endocnidozoa, is low. It is

comprised for less than 40 species from phy-

logenetically distinct groups. These organisms

live in nearly all types of freshwater environ-

ments and are distributed in all continents,

except Antarctica, but only few species are

cosmopolitan (Jankowski et al., 2008). The

freshwater species from the class Hydrozoa

fall into phylogenetically disparate groups: the

cosmopolitan Hydra sp., the simple and solitary

polyps without medusae; Cordylophorinae, the

colonial hydroids Cordylophora sp. and Pachy-

cordyle sp.; the freshwater medusae Craspeda-

custa sp. and Limnocnida sp. and the enigmatic

polyp Calpasoma sp. (Bouillon & Boero, 2000;

Collins, 2002). The genera Pachycordyle sp. and

Limnocnida sp. are not represented in the Neo-

tropical region (Dumont, 1994).

Freshwater hydrozoans in the Neotropical

region, have been known from 1858 with one

record of Cordylophora sp, from Brazil made

by Van Beneden. The works of Burger (1906),

Smith (1925) and Froehlich (1963) cited for the

first time specimens of Hydra sp., Craspedacus-

ta sp. and Calpasoma sp., respectively. However,

there is still a significative knowledge gap about

the distribution of these genera.

In this review, the specific bibliography of

Calpasoma sp., Cordylophora sp., Craspedacusta

sp. and Hydra sp. corresponding to the Neotrop-

ical region was analyzed, including the entire

South American continent, Central America,

the Antilles and Mexico. The main informa-

tion extracted was geographic distribution and

diagnostic characteristics. As a result of this

review, we present a checklist’s classification

following the last update of WoRMS of the

taxonomic classification, the most recent iden-

tification keys and discussions of the status of

some species.

The main objective of this review is to

identify the existing knowledge in the gen-

era of freshwater hydrozoans, analyze and

synthesize them, establishing a solid base for

future research.

The compiled information comes from

scientific literature and the online databases

GBIF (Global Biodiversity Information Facil-

ity: http://www.gbif.org), THL (The Hydra

Library: http://www.biology.pomona.edu/mar-

tinez/library.html), BHL (Biodiversity Heritage

Library: www.biodiversitylibrary.org), SNRD

(Sistema Nacional de Repositorios Digitales:

https://repositoriosdigitales.mincyt.gob.ar/

vufind/), WoRMS (World Hydrozoa Databases

belonging to World Register of Marine Species:

www.marinespecies.org/hydrozoa) (Schuchert,

2022) and observations from iNaturalist (www.

inaturalist.org).

Métodos: Analizamos la literatura mundial específica y diferentes bases de datos en línea, presentando en este

trabajo un nomenclador, las calves de identificación más recientes, incluyendo, además, discusiones sobre el

estado de algunas especies.

Resultados: Este análisis revela que al menos 15 países pertenecientes a la región Neotropical contienen reportes

de hidrozoos dulceacuícolas. Panamá, Brasil y Argentina son los países con mayor número de hallazgos.

Conclusiones: La disparidad de ambientes donde estos géneros han sido hallados (desde el Estrecho de

Magallanes hasta México) ofrece una clara visión de su amplia distribución y su gran adaptabilidad a diferentes

ambientes. Revela el vacío de información que aún existe sobre estos organismos dulceacuícolas, y la importancia

de retomar esta línea de investigación, para ampliar el conocimiento sobre su distribución, biología y ecología,

especialmente para aquellas especies consideradas invasoras.

Palabras clave: Cnidarios; aguas continentales; región Neotropical; especies de agua dulce.

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

Remarks of Calpasoma dactylopterum

Fuhrmann, 1939: It has been referred in some

reviews as a tentaculate form of Craspedacusta

sp., some authors have even observed the trans-

formation of the Craspedacusta sp. polypoid

into a Calpasoma-like polyp (Holstein & Ems-

chermann, 1995). The reproductive experi-

ments developed by Spira (1964) and Matthews

(1966), led them to believe that they were dif-

ferent species. However, Jankowski (2001) con-

sidered at least one form of Calpasoma sp. to

be congeneric with Craspedacusta sp., besides

in all other studies where Craspedacusta sp.

polyps have been cultured, this conversion has

never been observed (Kuhl, 1947; Lytle, 1961;

McClary, 1959; Reisinger, 1957). This species

lives attached to plant substrates in natural or

artificial ponds. These small tentaculate polyps,

which rarely exceed a millimeter in length,

are solitary and reproduce asexually originat-

ing propangles from their tentacles (Buchert,

1960; Dioni, 1974; Matthews, 1966; Rahat &

Campbell, 1974).

The genus Calpasoma sp. has only been

found so far in three countries: Argentina,

Brazil and Uruguay (Table 1). All these obser-

vations are longstanding, the most recent dates

from 1983 from Brazil, however morphological

descriptions are quite accurate.

Remarks of Cordylophora caspia Pallas,

1771: Clonal and athecate hydroid with medusa

Classification and checklist of freshwater hydrozoans from the Neotropical region

Phylum Cnidaria Hatschek, 1888

Class Hydrozoa Owen 1843

Subclass Trachylinae Haeckel, 1879

Order Limnomedusae Kramp, 1938

Family Olindiidae Haeckel, 1879

Genus Calpasoma Fuhrmann, 1939

Calpasoma dactylopterum Fuhrmann, 1939

Genus Craspedacusta Lankester, 1880

Craspedacusta sowerbii Lankester, 1880

Subclass Hydroidolina Collins, 2000

Order Anthoathecata Cornelius, 1992

Suborder Filifera Kühn, 1913

Family Cordylophoridae von Lendenfeld, 1885

Genus Cordylophora Allman, 1844

Cordylophora caspia Pallas, 1771

Suborder Aplanulata Collins, Winkelman, Hadrys & Schierwater, 2005

Family Hydridae Dana, 1846

Genus Hydra Linnaeus, 1758

Hydra viridissima Pallas, 1766

Hydra vulgaris Pallas, 1766

Hydra magellanica Schulze, 1927

Hydra pseudoligactis Hyman, 1931

Hydra paranensis Cernosvitov, 1935

Hydra iheringi Cordero, 1939

Hydra thomseni Cordero, 1941

Hydra plagiodesmica, Dioni 1968

Hydra intermedia Carvalho-Whole, 1978

Hydra salmacidis Lang da Silveira, 1996

H. vulgaris pedunculata Deserti, Zamponi & Escalante, 2011

4Revista de Biología Tropical, ISSN: 2215-2075 Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

stage lacking (Pennak, 1989). Reproduces sexu-

ally by new free-swimming planula larvae. It is

dioecious with gonophores containing eggs or

sperm (Folino, 2000). Colonies are polymor-

phic and grow by adding hydrants to hydro-

cauli on the upright branches and extending

the stolon or hydrorhiza (Jormalainen et al.,

1994). This organism is able to survive unfa-

vorable environmental conditions via spheres

of coenosarcs tissue, called menonts, which

regenerate when conditions are restored (Roos,

1979). This survival strategy and the ability to

adapt to a wide salinity range contribute to its

current large distribution, considered in many

regions as an invasive species (CABI Digital

Library, 2016).

There are eleven records of C. caspia from

Argentina, Chile, Uruguay and Brazil (Table 2).

According to Roch (1924) the first record of C.

caspia from Brazil was made by van Beneden

in 1858. Therefore, Silveira & Boscolo (1996)

considered it doubtful, then Haddad & Naka-

tani (1996) made the first official record 133

years later.

In Panama C. caspia was reported in dif-

ferent regions of the Panama Canal (Folino-

Rorem et al., 2009; Hildebrand, 1939; Jones &

Rützler, 1975). However, none of the records

provide morphological information associated

with the specimens.

The oldest report of C. caspia, from 1925,

is in the database GBIF, it was collected by Hil-

debrand in Gatun locks of the Panama Bay and

deposited in the Smithsonian National Museum

of Natural History (NMNH) (Orrell, 2022). The

specimens officially cited in Hildebrand (1939)

correspond to samples collected ten years later,

during 1935 and 1937. Other 20 records cor-

respond to specimens collected in the lower

east chamber of Gatun locks, one from Gatun

Lake, At Air Strip NW of Gamboa, and another

ten from Panama Bay, Pedro Miguel locks. The

specimens of these 31 records are deposited

in NMNH (Orrell, 2022). These records do

not include morphological information. The

references of the seven records corresponding

to Mexico (six of them without morphological

information) and the only one from Colombia

are included in Table 2.

Remarks of Craspedacusta sowerbii

Lankester, 1880 [= Limnocodium Allman,

1880 = Mycrohydra Potts, 1885, according

to Schuchert (2022)]: Freshwater hydrozoan

commonly observed in the medusa stage. The

species blooms seasonally, having mainly a sub-

tropical to temperate distribution (Gasith et al.,

2011; Jakovčev-Todorović et al., 2010; Jankows-

ki, 2001; Jankowski et al., 2008; Karaouzas et al.,

2015). Its life cycle includes both polyp (assum-

ing asexual reproduction) and free–swimming

stages (involved in sexual reproduction) (Gasith

et al., 2011). The free swimming-pelagic stage is

sporadic, lasting only few weeks, usually dur-

ing the late summer and autumn (Minchin et

al., 2016). The polyp stage is often overlooked

because of its small size (usually less than one

millimeter) and both stages are rarely reported

together (Failla et al., 2017).

The polyp form, previously described as

Microhydra ryderi (Potts, 1885), are cylindrical,

without tentacles. They are commonly solitary

Tabl e 1

Calpasoma dactylopterum Fhurmann, 1939 from Argentina, Uruguay and Brazil. (*) No information.

Country Region Morphological description Author

Argentina University of Buenos Aires

(vegetation from Corrientes)

Small polyps (0,4 mm in length). Hyaline tentacles.

Basitrich eurytele. Small propangles

Dioni (1974)

Uruguay Rodó Park (artificial pond)

Montevideo

Same characteristics as Argentine polyps. Dioni (1974)

Brazil University City of Sao Pablo Light grey polyps (0.5 mm in length). Hyaline tentacles.

Consider the polypoid form of Craspedacusta

Froehlich (1963)

Southeast of Sao Paulo state (*) Domaneschi &

Coneglian (1983)

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

Tabl e 2

Cordylophora caspia Pallas, 1771 from Argentina, Uruguay, Chile, Brazil, Colombia and Mexico. (*) No information.

Country Region Morphological description Author

Argentina Río Santiago (tributary

of Río de la Plata estuary)

Slightly and whitish colony. Hydrants 11-17

mm length. 8 to 28 fine and filiform tentacles.

Hydrocauli base with rings. Abundant oval female

gonophores

Gaggero (1923)

Chascomús lake

(Rio Salado basin)

Albicola form. Slightly and yellowish hydrocauli

(0.18 mm diameter). Stenoteles and desmonemes.

Ringuelet & Olivier

(1954)

Lobos Lake (Rio Salado

basin)

Lacustris form. Dark brown hydrocauli and stolons

(0.155 mm diameter). 15-20 tentacles. Abundant

round and oval gonophores (one to eight embryos)

Ringuelet & Olivier

(1954)

Puerto Yeruá (Entre Ríos) (*) Liotta & Wagner (2003)

Nahuel Rucá lagoon

(Buenos Aires)

Albicola form. Gastrozooids 1.21 to 3.95 mm

length. Four to seven fine and filiform tentacles.

Cylindrical stolons. Hydrocauli base with rings.

Desmonemes and heterotrichous microbasic

eurytele. Menont (12.5 μm in diameter).

Deserti et al. (2015)

Uruguay Las Brujas stream, tributary

of the Santa Lucia River

(Montevideo)

Albicola form. Dark, brown and cylindrical stolons.

Fusiform gastrozooids with 15 tentacles.

Cordero (1941b)

Chile Fjord Comau (Los Lagos

region)

(*) Galea (2007)

Brazil Paraná river, Foz do Iguaçu

(Paraná)

Hydrocauli 0.3 to 2 cm length. Abundant male and

female gonophores

Haddad & Nakatani

(1996)

Estuary of Rio Ubatuba

(Sao Paulo)

Male and female colonies. Hydrocauli up to 3.5 cm

length. 9 to 16 tentacles. Elliptical gonophores.

Silveira & Boscolo

(1996)

Funil Plant, Itatiaia

(Rio de Janeiro)

Regularly branched colonies. Hydrocauli base with

rings. 16-20 tentacles. Gonophores ovate invested

in a gonangium-like extension of perisarc.

Grohmann (2008)

Reservoir Governador

José Richa (Paraná)

(*) Borges (2008) & da Silva

(2021)

Colombia Santa Marta Branched colonies. 12-16 tentacles per hydrant.

Oval gonophores

Wedler (2017)

Mexico Mandinga lagoon (Veracruz) (*) Rioja (1959)

San Juan river (Nuevo León) (*) Guajardo et al. (1987)

Mandinga Estuary (Veracruz) (*) López-Ochoterena &

Madrazo-Garibay (1989)

Gulf of Mexico, Veracruz and

Campeche

(*) Okolodkov et al. (2007)

Gulf of Mexico (*) Authors consider a nonindigenous species Calder & Cairns (2009)

Veracruz Reef System

National Protected Area (Gulf

of Mexico)

Monopodial colony. Pale pink or yellowish

hydrants. 14-27 scattered filiform tentacles.

Eurytele and desmoneme.

Jerónimo (2013)

Cayo Arenas Reef (Gulf of

Mexico)

(*) Mendoza-Becerril et al.

(2020)

6Revista de Biología Tropical, ISSN: 2215-2075 Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

or form small colonies of two to four polyps

(Russell, 1953). As explained above, Calpasoma

sp. is usually considered to be the polypoid ten-

tacular form of Craspedacusta sp.

The species C. sowerbii develops a resting

stage under unfavorable environmental condi-

tions, an adaptation that confers it high survival

potential and enhances its dispersal capacity.

There is a consensus about its human mediated

introduction through fish and aquatic plants

and it is considered globally as an invasive spe-

cies of lakes (Dumont, 1994; Fritz et al., 2009;

Marsden & Hauser, 2009).

In South America, this genus has been

found in Argentina, Brazil, Uruguay, Chile and

Venezuela (Table 3). Brazil and Chile, respec-

tively, contain the greatest number of records,

however nine of the 13 total citations from

Tabl e 3

Craspedacusta sowerbii Lankester, 1880 from Argentina, Uruguay, Chile, Brazil, Venezuela, Mexico, Panama, Belize and Costa

Rica. (*) No information.

Country Region Morphological description Author

Argentina Lake of General San Martin Park

(Mendoza)

Female adults. 11 mm umbrellar diameter.

Mouth with four lips. Four perradial

channels. Four larger perradial tentacles.

First, second and third order tentacles.

Velum. Heterotrichous microbasic eurytele.

Oval gonads.

Ringuelet (1950)

Lake of General San Martin Park

(Mendoza)

Reexamination of material deposited by

Ringuelet (1950) in La Plata Museum

Vannucci & Tundisi

(1962)

La Florida (San Luis) and Horco

Molle reserve (Tucumán)

(*) Richard (1990)

Rio III Reservoir (Córdoba) Female specimens. Medusae 7-16 mm

diameter. Gonads with pistolera form.

Boltovskoy & Battistoni

(1981)

Valle Medio (Rio Negro) (*) Validated by GBIF Tormo (2014)

Uruguay Artigas and Durazno departments Female medusae 8-10 mm diameter and 4-5

mm high

Mañé Garzón &

Carbonell (1971)

Del Medio Lagoon (upper basin

of the Santa Lucía river) (Florida

department)

Live colony (666.5-1 152.2 μm length).

Solitary polyps (450-663 μm length).

Transparent hydroids without tentacles.

Nematocysts surrounding the hypostome

forming a spherical capitulum. Frustules

elongated and rod-like

Failla Siquier et al.

(2017)

Chile Tranque Marga-Marga

(Valparaiso)

Medusae 5-10 mm diameter. Four to seven

series of tentacles

Porter & Schmitt (1942)

Valparaiso (*) Vannucci & Tundisi

(1962)

Laguna Grande de San Pedro

(Concepción)

Adult female medusae 10.21 diameter.

Velum and manubrium. Four perradial

channels. Oval gonads. First, second and

third order tentacles. Oval and elongated

nematocysts

Quezada (1969)

Playa Tranquila, Lanalhue lake,

Contulmo (Arauco)

Medusae 8-15 mm diameter Quezada & Aurora

(1973)

Peñuelas reservoir (Valparaiso) (*) Schmid-Araya & Zúñiga

(1992)

Carilafquén lagoon (Araucania

region)

(*) Figueroa & de los Ríos

(2010)

Illahuapi lagoon, De Los Ríos

(Ranco)

Medusae 4-20 mm diameter. Four types of

tentacles. Four gonads.

Caputo Galarce et al.

(2013, 2018)

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

Country Region Morphological description Author

Del Bío-Bío, De La Araucania and

De Los Ríos region

(*) Single haplotype. Fuentes (2015)

Santa Elena (Bío-Bío region) Medusae 2.3 cm length. Four visible gonads Fraire-Pacheco et al.

(2017)

Mediterranean and Valdivian

ecoregion

(*) Single, unique C. sowerbii haplotype in

both ecoregions.

Fuentes et al. (2019)

Lake Illahuapi and San Pedro

(Valdivian ecoregion)

Illahuapi medusae 1.6 and 2.2 cm2 umbrellar

area, slightly brownish gonads. San Pedro

medusae 1.4 and 3.2 cm2 umbrellar area,

whitish gonads. Two studied lakes host

clonal population

Caputo Galarce et al.

(2021)

Los Lagos region (Llanquihue) (*) Collected in 2020. Validated by GBIF iNaturalist

Brazil Porto Alegre (Rio Grande do Sul) (*) Polyps and medusae. Gliesch (1930)

Belo Horizonte (Minas Gerais) (*) Only female medusae Martins (1941)

Belo Horizonte (*) Sawaya (1957)

São Paulo (*) Polypoid form Froehlich (1963)

Minas Gerais (*) Bandeira de Mello et al.

(1971)

Curitiba (*) Loyola e Silva & Oliveira

(1988)

Serra da Mesa HPP Reservoir

(Goiás)

(*) De Filippo et al. (1999)

Lajeado UHE (*) Reis Pereira (2002)

Lagoa Misteriosa (Mato Grosso

do Sul)

Juvenile 7.8 mm diameter. Adults 25 mm

diameter

Silva & Roche (2007)

14 de Julho Plant, Cotiporã (Rio

Grande do Sul)

Medusae 5- 3 mm diameter Schwarzbold et al. (2010)

Lagoa Azul, Prados (Minas Gerais

state)

(*) Souza & Ladeira (2011)

Passo Fundo (Rio Grande do Sul) Medusae 8.1-11.5 mm diameter.

Nematocysts in groups on papillae.

Marginal cnidocyst ring. Four simple radial

channels. Hanging, pouchlike gonads on

radial channels.

Savaris et al. (2013)

São Valentim (Rio Grande do Sul) Medusae 5-15 mm diameter Restello et al. (2015)

Venezuela Lagartijo Reservoir (*) Infante & Infante (1994)

Lagartijo and Camatagua

reservoir, Aragua and Guanapito

(Guárico)

(*) Guajardo et al. (1987)

Mexico Rodrigo Gomerza reservoir

(Nuevo León)

(*) Guajardo et al. (1987)

Adolfo López Mateos reservoir,

Badiraguato (Sinaloa)

Female medusae 10-19 mm bell diameter.

iNaturalist reports C. sowerbii also for this

site. Validated by GBIF

Moreno-Leon & Ortega-

Rubio (2009)

Panama Gatun Lake, Panama Canal Male medusae 9-19 mm diameter Smith (1925)

Gatun Lake, La Chorrera, Panama

Oeste

(*) Collected in 2019. Validated by GBIF iNaturalist

Belize Green Hills Butterfly Ranch (Cayo

District)

(*) Collected in 2124. Not yet validated. iNaturalist

Costa Rica Arenal reservoir (Guanacaste) (*) Murillo (1989)

8Revista de Biología Tropical, ISSN: 2215-2075 Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

Brazil, do not contain any type of morphologi-

cal information. The second oldest record of

C. sowerbii from Brazil was made for Martins

(1941) and he was the first author to assume

that this species has been introduced to the

country through fish imported from Europe.

The records from Brazil, Mexico, Panama,

Belize and Costa Rica are listed in Table 3.

Remarks of Hydra Linnaeus, 1758 [=

Pelmatohydra Schulze, 1914 = Clorohydra

Schulze, 1914 according to Schuchert (2022)]:

Sessile and solitary polyps that occurs in all

continents, except Antarctica (Jankowski et

al., 2008; Kaliszewicz, 2013). This genus can

be found in any reasonably unpolluted body

of freshwater during any season (Bossert &

Galliot, 2012). It is usually more abundant

in lentic waters, often attached to submerged

and floating macrophytes (Elliot et al., 1997;

Schwartz et al., 1983).

All Hydra sp. species constitute a mono-

phyletic clade (Collins et al., 2006) and are

clustered into four morphological groups:

viridissima, vulgaris, oligactis, and braueri, cor-

roborated by DNA analyses (Campbell, 1983;

Martínez et al., 2010).

Table 4 lists the most relevant results

for the genus Hydra in the mentioned study

area. Additionally, for Argentina, another four

records refer to Hydra plagiodesmica, but do not

provide morphological details (Alzugaray et al.,

2013, 2019, 2021; Poggio Herrero et al., 2014).

Also, Hydra have been reported in tributaries

Tabl e 4

Hydra Linnaeus, 1758 from Argentina, Uruguay, Chile, Brazil, Paraguay, Venezuela, Peru, Ecuador, Colombia, Panama,

Mexico, Costa Rica and Trinidad and Tobago. (*) No information.

Country Region Specie Morphological description Author

Argentina Río Salado (Santa Fé) Hydra

plagiodesmica

Green. Column 0-12 mm length. Six to

eight fine and long tentacles with three

distinctive growth patterns. Protandric

hermaphrodite. Embryotheca with

penta or hexagonal prisms. Pyriform

stenoteles, oval desmonemes, oval and

elongated holotrichous isorhiza

Dioni (1968)

Los Padres lagoon

(Buenos Aires)

Hydra

viridissima

Green. Column 1.82-3.10 mm

length. Five or six short, transparent

and moniliform tentacles. Pyriform

stenoteles, spherical desmonemes,

seed-shaped atrichous isorhiza and two

morphotypes of holotrichous isorhiza

Deserti (2016)

Nahuel Rucá lagoon

(Buenos Aires)

Hydra

viridissima

Green. Column 0.60-2.89 mm length.

Six to eight tentacles. Holotrichous

isorhiza slightly larger than the

stenoteles.

Deserti (2016)

Los Padres lagoon

(Buenos Aires)

Hydra vulgaris Brown. Column 1.98-9.88 mm length.

Six to nine moniliform large tentacles.

Dioecious. Round embryotheca.

Holotrichous isorhiza with paramecium

shape

Deserti, &

Zamponi

(2011)

La Brava (Buenos

Aires)

Hydra vulgaris Brown. Medium-sized. Five to eight

large, transparent and moniliform

tentacles with discontinuous pattern

growth. Separate sexes.

Deserti, (2016)

Nahuel Rucá (Buenos

Aires)

Hydra vulgaris Five to seven tentacles. Same

characteristic observed in La Brava

Deserti, (2016)

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

Country Region Specie Morphological description Author

Los Padres, Nahuel

Rucá, La Brava lagoons

(Buenos Aires)

Hydra vulgaris

pedunculata

Brown. Stalk. Column 1.97-9.88 mm

length. Six or seven transparent,

moniliform large tentacles with growth

pattern discontinuous.

Deserti et al.

(2011) and

Deserti, (2016)

Nahuel Rucá (Buenos

Aires)

Hydra

pseudoligactis

Brown. Column 2.12-5.78 mm

length. Stalk. Six to nine transparent,

moniliform and large tentacles with

pattern growth typical of braueri group.

Deserti et al.

(2012)

Uruguay Santiago Vasquez,

Bellaca Canyon, stream

Miguelete and Arrozal

Treinta y Tres

Chlorohydra

viridissima

Green. Columns 0.5-5.5 mm in length.

Seven to ten tentacles. Some specimens

had simultaneously testes and ovaries.

Ootheca surrounded by a thin capsule

and attached by a conical funiculus to a

broad rim.

Cordero

(1941b)

Santiago Vasquez,

Bellaca Canyon, stream

Miguelete

Hydra

attenuata

thomseni

Orange to red. Straight column 4-12 mm

in length. Six to nine large tentacles with

pattern growth discontinuous. Stenoteles

with two measurements, pyriform

desmonemes, elliptical holotrichous

isorhiza and oval atrichous isorhiza.

Dioecius. Embryotheca with spines

Cordero

(1941b)

Chile Santiago de Chile Hydra grisea Orange. Column 14 mm in length. Six to

ten large tentacles. Unclear description

of nematocysts (measurements refer to

stenoteles, but drawings to atrichous

isorhiza)

Burger (1906)

Ñuñoa near Santiago

de Chile

Hydra viridis Green. Columns up to 6 mm in length.

Eight to ten tentacles. Only highlights

the longest stinging capsules (we assume

that it refers to stenoteles)

Burger (1906)

Strait of Magellan

(Punta Arenas)

Hydra

magellanica

Small stenoteles, oval holotrichous

ishorriza, elongated and oval atrichous

isorhiza

Schulze (1927)

Brazil Pernambuco state Hydra sp. (*) Schubart (1938)

Ceará state Hydra

viridissima

(*) Green Cordero (1939)

Alagôas, Paraiba and

Ceará states

Hydra iheringi Orange. Column 3-6 mm length. Four

to six tentacles

Cordero (1939)

São Paulo state Hydra

viridissima

Green. Column 1.55 mm length. Five to

nine short tentacles. Separated sexes

Carvalho

Whole (1978)

São Paulo state Hydra

intermedia

Brown. Column 2-12 mm length. Five

to nine short tentacles, arise on buds

successively. Dioecius. Embryotheca

with short spines

Carvalho

Whole (1978)

University of

São Carlos,

(São Paulo state)

Hydra

viridissima

Green. Column 0.8-2 mm length Massaro &

Rocha (2008)

10 Revista de Biología Tropical, ISSN: 2215-2075 Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

Country Region Specie Morphological description Author

São Paulo state Hydra

salmacidis

Brown. Columns 8.6-12.5 mm length.

Four to eight filiform tentacles. Pattern

growth simultaneous. Monoecious,

protandrous with sex reversal. Rounded

embryotheca with small spines.

Stenotele larger than other types

Silveira et al.

(1997)

Paraguay Rio Paraná Hydra

paranensis

Light yellowish. Columns 4-5 mm

length. Oval stenoteles, oval and

elongated holotrichous isorhiza

Cernosvitov

(1935)

Hernandarias (Alto

Paraná)

Hydra sp.(*) Collected in 2016. Not yet validated iNaturalist

Venezuela Paraiso (Caracas) Hydra

viridissima

Green. Column 1-2 mm length.

Monoecius

Cordero

(1941b)

Paraiso (Caracas) Hydra sp. Pale yellow. Column up to 5 mm

length. Five to seven tentacles with

simultaneous growth. Oval stenoteles,

desmonemes and atrichous ishorriza,

oval and elongated holotrichous

isorhiza. Dioecious

Cordero

(1941b)

Peru Ojo del Milagro,

Characato district

(Arequipa)

Hydra vulgaris (*) Huarachi &

González

(2012)

ACTS Field Station

and Canopy Walkway,

Maynas (Loreto region)

Hydra sp. (*) Brown. Collected in 2019. Validated

by GBIF

iNaturalist

Ecuador Cumbayá (Quito),

Ibarra (Imbabura),

Pedro Moncayo

(Pichincha) and

Calvario and Sendero

Llaviucu (Azuay)

Hydra sp. (*) Collected in 2005, 2009, 2017, 2019

and 2021 Not yet validated

iNaturalist

Cumbayá and Huayna-

Capac (Azuay)

Hydra

viridissima

(*) Collected in 2019 and 2021.

Validated GBIF

iNaturalist

Colombia Bogotá (Cundinamarca)

and Santa Marta

(Magdalena)

Hydra sp. (*) Brown. Collected in 2019 and 2022.

Not yet validated

iNaturalist

Bogotá Hydra

viridissima

(*) Collected in 2017 and 2022.

Validated by GBIF

iNaturalist

Panama Antón River, Antón

Valley (Coclé)

Hydra vulgaris (*) Martinez et al.

(2010)

La Cabaña

(Boca del Toro)

Hydra sp.(*) Brown. Collected in 2017. Not yet

validated

iNaturalist

Mexico Lake Arareko

(Chihuahua)

Hydra vulgaris (*) Martinez et al.

(2010)

La Luna and El Sol

lakes (crater of the

Nevado de Toluca)

(State of Mexico)

Hydra vulgaris (*) Part of the benthic fauna Oseguera et al.

(2016)

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

of the Río Paraná, however these works provide

little information associated with the speci-

mens, not even mention their colors (Marchese

& Drago, 1983; Paporello de Amsler, 1987).

The same happens with the records from Sauc-

esito and Las Tunas rivers (Río Paraná) (Pavé &

Marchese, 2005) and from Lake Nahuel Huapi,

Rio Negro (Trochine et al., 2008, 2009). The

same occurs with H. vulgaris which has been

reported in Argentina in five locations: two

from Córdoba province, one from Neuquén

province and two from Buenos Aires (Martínez

et al., 2010). These records do not include

morphological information associated with the

specimens. Finally, during 2019 and 2020, H.

viridissima was reported in Argentina from the

capital of Santa Fé province and specimens of

brown hydras from the department of Punilla,

Córdoba province, respectively and the data

was validated by GBIF site (iNaturalist, 2022).

In Bolivia, there are records of hydras in

the lagoons of the Trinidad flood zone (Pouilly

et al., 2004). However, they are somewhat

doubtful because do not provide additional

data on these observations (such as coloration,

size or number of specimens) on its own obser-

vations or those of other researchers, so we do

not know if they have been omitted or if their

occurrence is a mere assumption.

For Brazil, Cordero (1939) based the deci-

sion to name a new species for the genus Hydra

on the fact that the specimens differed from

others described for South America on the

dimensions of their nematocysts. Considering

the coloration and the presence of peduncle, the

species could belong to H. oligactis group or to

H. vulgaris pedunculata, a subspecies of the H.

vulgaris group.

In addition to the results listed in Table

4, there are four more records from Brazil:

from Governador José Richa plant in south-

ern, and brown polyps collected in Lago Sul

in Brasilia, and Rio Paranaíba in Minas Gerais

(Da Silva-Bertão et al., 2021; iNaturalist,

2022), all citations without morphological data

of the specimens.

In the case of Chile and in addition to

the records listed in Table 4, include the

findings of H. vulgaris from Punta Arenas

and H. viridissima from Puerto Guadal, all

of them without morphological descriptions

(Martínez et al., 2010).

The records of Hydra sp. listed in Table 4

from Colombia, Ecuador, Costa Rica, Mexico,

Panamá, Perú and Trinidad and Tobago, do not

contain morphological descriptions.

Summary on the state of the of freshwater

hydrozoan in the Neotropical region

There are approximately 170 records of

freshwater hydrozoans from fifteen countries of

the Neotropical region. Panama has the greatest

Country Region Specie Morphological description Author

Dolores, Tepotzotlán

(State of Mexico)

Hydra sp. (*) Rivera De la

Parra et al.

(2016)

Santiago (Nuevo

León), Lerma (State of

México) and Coyoacán

(Mexico City)

Hydra

viridissima

(*) Collected in 2018 and 2020.

Validated by GBIF

iNaturalist

Presa del Llano,

Villa del Carbón

(State of Mexico)

Hydra oligactis (*) Collected in 2021. Not yet validated.

Only consider as brown hydras

iNaturalist

Costa Rica Arenal lagoon, Piedras

River, De Los Ahogados

River and tiny brook near

Limonal (Guanacaste)

Hydra vulgaris (*) Martinez et al.

(2010)

Trinidad and

Tobago

Dibe, Port of Spain (Diego

Martin region)

Hydra sp.(*) Brown. Collected in 2021. Not yet

validated

iNaturalist

12 Revista de Biología Tropical, ISSN: 2215-2075 Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

number of records, followed by Brazil, Argen-

tina, Chile, Mexico, and Uruguay (Fig. 1). Most

of the records from Panama are represented by

preserved specimens of C. caspia deposited in

NMNH, rather than bibliographic citations.

Among the various countries, C. sowerbii

leds the records from Brazil and Chile, Hydra

sp. from Argentina and Uruguay, and Cordy-

lophora sp. from Mexico. The genus Hydra

sp. is the most of cited overall. For this genus,

Argentina has the greatest number of records

and diversity of species (four species and one

subspecies), followed by Brazil with four spe-

cies, three of which are endemic. Chile and Par-

aguay share the same situation as Brazil, with

the endemics H. magellanica and H. paranensis,

respectively, the latter species being the second

oldest report of the genus for South America.

The first official record of freshwater

hydrozoans in the Neotropical region was made

with the discovery of Hydra sp. in Chile by

Burger in 1906. However, the author does not

guarantee the name of this species and only

mentions the morphological similarities with

H. grisea Linnaeus, 1767, which was originally

described only from North America and later

considered synonymous with H. vulgaris. Con-

sequently, these specimens are now cited as

Hydra sp. officially.

Since this first record, many species have

been described, leading to some limitations,

for example, over the time many of these spe-

cies have been rejected and accepted as syn-

onyms, primarily for H. vulgaris Pallas, 1766.

This species has nine synonyms: H. grisea

Linnaeus, 1767; H. vulgaris var. aurantiaca

Ehrenberg, 1838; H. carnea L. Agassiz, 1851; H.

trembleyi Haacke, 1879; H. americana Hyman,

1931; H. littoralis Hyman, 1931; Moerisia alberti

Leloup, 1938; H. magnipapillata Itô, 1947 and

recently, H. shenzhensis Wang & Deng, 2012

(Schuchert, 2022).

A similar case occurs with H. circum-

cincta Schulze, 1914 of the braueri group, that

has seven synonyms, of which H. attenua-

ta Pallas, 1766 is the most cited in the lit-

erature (Schuchert, 2022). However, Lenhoff

(1983), Campbell (1987) and Holstein et al.

Fig. 1. Distribution and morphologies of the four genera of freshwater hydrozoans for the study area. A. South America.

B. Central America, the Caribbean and Mexico and C. Morphologies of the four genera (modified from Campbell, 2016).

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

(1990), considered H. attenuata as synonym

of H. vulgaris. H. littoralis, H. vulgaris and H.

magnipapillata are species restricted to North

American territory, Europe, and Japan, respec-

tively. Today, these three species are considered

as H. vulgaris.

While Campbell (1987) and Holstein et al.

(1990) consider H. oligactis as a cosmopolitan

species, Jankowski et al. (2008) restricts the

oligactis group to North America and Eurasia.

In addition, they consider the species of the

vulgaris group as cosmopolitan with slight dif-

ferences between H. vulgaris from boreal and

southern zones.

Such has been the confusion in this genus

that even Wagner (1833) described the new

species Hydra aculeata, a species later con-

sidered a basonym of Hydractinia aculeata, a

marine colonial hydrozoan that belongs to the

suborder Filifera.

Cordero (1941b) described the subspecies

H. attenuata thomseni from Uruguay, which

was later rejected as a parent of H. attenuata =

H. circumcincta. However, it was subsequently

promoted to a species and renamed H. thom-

seni by Schuchert in 2022. In addition, Cor-

dero (1941b) reported on specimens found in

Venezuela but did not assign them the species

rank. The observed morphological character-

istics of these specimens resemble those of the

North American species H. littoralis, which is a

synonym of H. vulgaris. Therefore, it is highly

likely that Cordero’s finding corresponds to

the cosmopolitan H. vulgaris, as in the case

of Burger (1906). The variety of reproductive

strategies in this group reinforces the notion

that Cordero’s finding corresponds to H. vul-

garis (Campbell, 1987; Lenhoff, 1983).

The records of H. vulgaris from other ten

countries, expands knowledge about their dis-

tribution and reinforces the idea of Jankowski

et al. (2008) that it is a cosmopolitan species.

The records of Martínez et al. (2010) from

Chile show that the species has reached the

southernmost point of the American continent

and could even validate the idea that the speci-

mens found by Burger (1906) from Santiago de

Chile corresponded to the species H. vulgaris.

The species H. magellanica, described by

Schulze (1927) from the Strait of Magellan,

could belong to the vulgaris group or even be a

synonym of H. vulgaris. Although it currently

retains its species status (Schuchert, 2022), a

new review may be needed given the antiquity

of its finding and the contributions made by

Martínez et al. (2010).

The anatomical difference found in the

subspecies H. vulgaris pedunculata is not mani-

fested at the molecular level, since the conspic-

uous and translucent peduncle, is a variation

that could respond solely to a phenotypic mani-

festation (Deserti, 2016). Martínez et al. (2010)

and Schwentner & Bosch (2015) worked with

Hydra sp. sequences of DNA from Chile and

Argentina, which are available in GenBank, that

showed clear differences in their mitochondrial

and nuclear markers, despite occurring sympat-

rically. Schwentner & Bosch (2015) proposed

that this difference may indicate that H. vul-

garis pedunculata should be promoted in rank,

declared as a new species. However, the results

obtained in the study of biodiversity of the

genus carried out by Deserti (2016), completely

rule out this interpretation, but does not dis-

card the possibility that other species exist. It is

a clear example of the existence of intraspecific

morphological variations that may have been,

until today, one of the causes of misinterpreta-

tion in the naming of new species.

Other variations or subspecies have been

reported in the literature, such as H. vulgaris

var. aurantiaca Ehrenberg, 1838 and H. attenu-

ata thomseni for Uruguay (Cordero, 1941a). In

WoRMS, the first one has been synonymized as

H. vulgaris (Schuchert, 2020). The second one,

as mentioned earlier, has been promoted to the

rank of species.

The viridissima group have been reported

in eight countries: Argentina, Brazil, Chile,

Uruguay, Venezuela, Mexico, Ecuador and

Colombia, represented by the species H. viridi-

ssima. Argentina is the only country with a

second species of this group: H. plagiodesmica,

but its description does not clearly distinguish

it from the species H. viridissima, H. sinensis

and H. hadleyi, so the validity of the species has

14 Revista de Biología Tropical, ISSN: 2215-2075 Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

been questioned (Campbell, 1987; Grayson,

1971). However, in WoRMS it is considered as

a valid report.

The genus Calpasoma sp. is the least rep-

resented and cited with only four records from

South America. Given the difficulty of finding

it, due to its small size and soft body, it is likely

that its abundance is underestimated. In fact, if

we consider this polyp as part of the life cycle of

Craspedacusta sp., the records of Calpasoma sp.

should coincide, at least asynchronously, with

those of that jellyfish stage.

The case of invasive freshwater hydrozoans

The genus Craspedacusta sp. is the third

one of freshwater hydrozoans with the largest

number of records. The first report was made

by Smith (1925) for Panama, but Chile is the

country with more records of this genus and

where the only molecular analysis on this genus

until today has been done.

This genus includes a still uncertain num-

ber of hydromedusan species (Jankowski et al.,

2008). The most reported around the world is

C. sowerbii Lankester, 1880. As in the genus

Hydra sp., the taxonomy of Craspedacusta sp.

is unsettled because of the large morphologi-

cal plasticity of the medusa stage (Lewis et

al., 2012). Of the three species recognized as

valid by the barcode of life database, C. kiat-

ingi, C. sowerbii and C. sinensis, only C. sow-

erbii is recognized as a global invader of lakes

(Fritz et al., 2009).

Although C. sowerbii is considered an inva-

sive species, native of the Yangtze River basin

in China, the type specimens described came

from a water–lily tank in Regent’s Park, Lon-

don, England in 1880 (Kramp, 1961; Lankester,

1880). For Oualid et al. (2019) it is somewhat

ironic that the type locality and the origin of

this species are not the same, besides they point

out that, in the type locality of C. sowerbii, the

aquatic plants of the water–lily tank in Regent’s

Park (i.e., the potential dispersal vector) were

imported from Brazil, and not from China, a

fact that could complicate more the scenario

about the true origin of this species.

Another problem related to the genus

Craspedacusta sp. is the difficulty of finding its

polyp form. For Duggan & Eastwood (2012), C.

sowerbii is more common and widespread than

it appears from jellyfish observations, making it

difficult to estimate the timing of the introduc-

tion of this species to a given region using only

the jellyfish findings.

As this species of hydromedusa is reported

in lists of exotic species, the correct identi-

fication of the different lineages becomes an

urgent challenge to correctly understand the

number of invasion events and the species of

the genus Craspedacusta that could be involved.

(Oualid et al., 2019).

The colonial polyp Cordylophora caspia

that has been reported in Argentina, Uruguay,

Chile, Brazil, Colombia and Mexico, is also

considered an alien species that besides causing

ecological damage, adds an economic problem

since it clogs the hydraulic and cooling systems

of hydroelectric plants (Grohmann, 2008). This

is one of the reasons for the considerable num-

ber of reports of this species for Panama in dif-

ferent sections of the Panama Canal, all of them

without morphological information.

The citation of Gaggero (1923) of C. lacus-

tris in Argentina, is the first mention of the

genus Cordylophora from South America and

the records of Hildebrand (1939) in Panama,

the first one for Central America.

The taxonomy of this genus is character-

ized by the same interpretation problems as

Hydra sp. and Craspedacusta sp., even some

works have suggested that C. caspia may be

a complex of species, because its high degree

morphological plasticity (Folino-Rorem et. al.,

2005). These authors stated that at least C. cas-

pia and C. lacustris are synonyms but suggested

the integration of molecular and morphological

analyses to clarify this question.

The analysis presented here demonstrates

three important points: 1) freshwater hydro-

zoans are a frequent group in the Neotropical

fauna; 2) given the appearance of the four

genera in very dissimilar natural environments

(even a point as southern as the Strait of Magel-

lan), we can infer the existence of this group

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

of cnidarians in those territories for which

there are still no official reports; and 3) a re-

examination of the cited species is imperative,

with solid molecular bases that clear up those

doubts about the really valid species, which

would allow to establish the true geographic

and phylogenetic distribution map, especially

for those invasive species,

KEYS TO CNIDARIA (modified from Deserti et al. 2020)

CLASS HYDROZOA: Families

Note: Cordylophora caspia is a synonym of C. lacustris Allman, 1844.

1 Medusae or solitary polyps with or without buds .................................... 2

1’ Branching colonies with polyps with several tentacles and a stolon attached to a substratum

Oceaniidae, one species: Cordylophora caspia Pallas, 1771 [Argentina, Brazil, Chile, Uruguay,

Colombia, Mexico and Panama]

2(1) Medusa form or polyps < 1 mm in length .................................. Olindiidae

2’ Single polyps >1 mm in length ........... Hydridae, one genus: Hydra [Argentina, Brazil,

Chile, Uruguay, Paraguay, Peru, Venezuela, Colombia, Mexico, Panama, Costa Rica, Bolivia,

Ecuador and Trinidad and Tobago]

HYDROZOA: OLINDIIDAE: Genera

Note: these two forms may be conspecific.

1 Polypoid and medusoid forms; polyps colonial, lacking tentacles .... Craspedacusta sowerbii

Lankester, 1880 [Argentina, Brazil, Chile, Uruguay, Venezuela, Mexico, Panama, Belize and

Costa Rica]

1’ Only solitary polypoid forms with tentacles .... Calpasoma dactylopterum Fhurmann, 1939

[Brazil, Argentina and Uruguay]

HYDROZOA: HYDRIDAE: HYDRA: Groups and species

1 Polyps not green; stenotele >11 mm in length; embryotheca either not piled or not roughly spheri-

cal ............................................................................. 2

1’ Green polyps due to endosymbiotic algae; nematocysts small; viridissima group ......... 4

2(1) Holotrichous isorhiza narrowly oval or reniform, width <0.5 length; embryotheca not flat-

tened .......................................................................... 3

2’ Holotrichous isorhiza broadly fusiform; embryotheca flattened against substratum ..braueri

group

3(2) Young bud lateral tentacles arising conspicuously early; conspicuous peduncle; embryotheca

smooth and thin .................................................... oligactis group

3’ Young bud tentacles arising in slightly staggered sequence or discontinuous; embryotheca

thick with numerous radial spines ....................... vulgaris group [Cosmopolitan]

4(1) Holotrichous isorhiza reniform; embryotheca with one narrow chamber proximal to embryo

Hydra viridissima Pallas, 1766 [Cosmopolitan]

4’ Holotrichous isorhiza stubby, not reniform; embryotheca with basal chambers in young

embryos ................................. Hydra plagiodesmica Dioni, 1968 [Argentina]

16 Revista de Biología Tropical, ISSN: 2215-2075 Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

Ethical statement: the authors declare that

they all agree with this publication and made

significant contributions; that there is no con-

flict of interest of any kind; and that we fol-

lowed all pertinent ethical and legal procedures

and requirements. All financial sources are fully

and clearly stated in the acknowledgments sec-

tion. A signed document has been filed in the

journal archives.

ACKNOWLEDGMENTS

SNS was supported by São Paulo

Research Foundation (FAPESP) grant number

2019/03552-0 and CNPq (Research Productiv-

ity Scholarship) grant number 301293/2019-8.

REFERENCES

Alzugaray, M. E., Adami, M. L., Diambra, L. A., Hernández-

Martínez, S., Damborenea, C., Noriega, F. G., &

Rondero, J. R. (2013). Allatotropin: An Ancestral

Myotropic Neuropeptide Involved in Feeding. PLoS

ONE, 8(10), e77520. https://doi.org/10.1371/journal.

pone.0077520

Alzugaray, M. E., Gavazzi, M. V., & Ronderos, J. R. (2019).

Calcium signalling in early divergence of Meta-

zoa: Mechanisms involved in the control of mus-

cle-like cells contraction in Hydra plagiodesmica.

Canadian Journal of Zoology, 824, 812–824. https://

doi.org/10.1139/cjz-2018-0295

Alzugaray, M. E., Gavazzi, M. V., & Ronderos, J. R. (2021).

G protein-coupled receptor signal transduction and

Ca2+ signaling pathways of the allatotropin/orexin

system in Hydra. General and Comparative Endo-

crinology, 300, 113637. https://doi.org/10.1016/j.

ygcen.2020.113637

Bandeira De Mello, M. L. I., Melucci Cavenaghi, T. M.

C. Melucci Cavenaghi& Resende, E. S. (1971).

Nova ocorrência de medusa de água doce em

Minas Gerais. Ciência e Cultura, Sâo Paulo, 23,

265. https://memoria.bn.br/docreader/DocReader.

aspx?bib=003069&pagfis=9976

Boltovskoy, A., & Battistoni, P. A. (1981). La medusa Cras-

pedacusta sowerbyi en el embalse Río Tercero, Córdo-

ba, Argentina. Physis, 39(97), 78.

Borges, P. D. (2008). Aspectos do ciclo de vida da espécie inva-

sora Cordylophora caspia (Cnidaria) no reservatório da

Usina Hidrelétrica Governador José Richa, Rio Iguaçu,

Paraná. Universidade Federal do Paraná. https://

acervodigital.ufpr.br/bitstream/handle/1884/30409/

Monografia%20Patricia%20Dammski%20Borges.

pdf?sequence=1&isAllowed=y

Bossert, P., & Galliot, B. (2012). How to use Hydra as

a model system to teach biology in a classroom.

International Journal of Developmental Biology, 56,

637–652.

Bouillon, J., & Boero, F. (2000). Synopsis of the families

and genera of the Hydromedusae of the world, with

a list of the worldwide species. Thalassia Salentina,

24, 47–296.

Buchert, A. (1960). Craspedacusta sowerbyi Lank., eine

Siisswasser Meduse und ihre beiden. Polyp-typen in

der Ungarischen Fauna. Acta Zoologica Hungary, 6,

29–54.

Burger, O. (1906). El jénero Hydra habitante de las aguas

dulces de Chile. Anales de la Universidad de Chile,

119, 135–139.

CABI Digital Library. (2023, March 28). Cordylophora in

Invasive Species Compendium. CABI Digital Library.

https://www.cabidigitallibrary.org

Calder, D. R., & Cairns, S. D. (2009). Hydroids (Cnidaria:

Hydrozoa) of the Gulf of Mexico. In D. L. Felder & D.

K. Camp (Eds.), Gulf of Mexico. Origin, waters, and

biota (Vol. 4. Biodiversity, pp. 381–394). Texas A&M

University Press.

Campbell, R. D. (1983). Identifying Hydra species. In H. M.

Lenhoff (Ed.) Hydra Research Methods (pp. 19–28).

Plenum Press.

Campbell, R.D. (1987), A new species of Hydra (Cnidaria:

Hydrozoa) from North America with comments on

species clusters within the genus. Zoological Jour-

nal of the Linnean Society, 91, 253–263. https://doi.

org/10.1111/j.1096-3642.1987.tb01510a.x

Caputo-Galarce, L., Riquelme, K. V., Osman, D. Y., & Fuen-

tes, R. A. (2013). A new record of the non-indigenous

freshwater jellyfish Craspedacusta sowerbii Lankes-

ter, 1880 (Cnidaria) in Northern Patagonia (40°

S, Chile). BioInvasions Records, 2, 263–270. http://

dx.doi.org/10.3391/bir.2013.2.4.01

Caputo-Galarce, L., Huovinen, P., Sommaruga, R., &

Gómez, I. (2018). Water transparency affects the

survival of the medusa stage of the invasive freshwater

jellyfish Craspedacusta sowerbii. Hydrobiologia, 817,

179–191.

Caputo-Galarce, L., Fuentes, R., Woelfl, S., Castañeda, L. E.,

& Cárdenas, L. (2021). Phenotypic plasticity of clonal

populations of the freshwater jellyfish Craspedacusta

sowerbii (Lankester, 1880) in Southern Hemisphere

lakes (Chile) and the potential role of the zooplank-

ton diet. Austral Ecology, 46, 1192–1197. https://doi.

org/10.1111/aec.13087

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

Carvalho-Wolle, L. (1978). Hydra intermedia sp. nov. and

notes on Chlorohydra viridissima (Pallas) (Cnida-

ria). Boletim de Zoologia, 3, 143–152. https://doi.

org/10.11606/issn.2526-3358.bolzoo.1978.121657

Cernosvitov, L. (1935). Ueber zwei Hydren aus Paraguay.

Zoologischer Anzeiger, 109(11–12), 307–311.

Collins, A. G. (2002). Phylogeny of Medusozoa and the

evolution of cnidarian life cycle. Journal of Evo-

lutionary Biology, 15(3), 418–432. https://doi.

org/10.1046/j.1420-9101.2002.00403.x

Collins, A. G., Schuchert, P., Marques, A. C., Jankowski,

T., Medina, M., & Schierwater, B. (2006). Meduso-

zoan phylogeny and character evolution clarified

by new large and small subunit rDNA data and an

assessment of the utility of phylogenetic mixture

models. Systematic Biology, 55, 97–115. https://doi.

org/10.1080/10635150500433615

Cordero, E. (1939). Observaciones sobre algunas especies

sudamericanas del género Hydra. I. Hydra en el

nordeste de Brasil. Anais da Academia Brasileira de

Ciências, 11, 335–340.

Cordero, E. (1941a). Observaciones sobre algunas especies

sudamericanas del género Hydra. II. Hydra y Cord-

ylophora en el Uruguay. Anais da Academia Brasileira

de Ciências, 13(3), 173–183.

Cordero, E. (1941b). Observaciones sobre algunas especies

sudamericanas del género Hydra. III. (1) Hydra en

Venezuela. (2) La acción de Hydra iheringi sobre las

larvas de ciertos peces del nordeste de Brasil. Anais

da Academia Brasileira de Ciências, 13(3), 195–201.

Da Silva-Bertão, A. P., Leite, R. V. V., Horodesky, A., Pie,

M. R., Zanin, T. L., Netto, O. S. M., & Ostrensky, A.

(2021). Ecological interactions between invasive and

native fouling species in the reservoir of a hydroelec-

tric plant. Hydrobiologia, 848, 5169–5185.

De Filippo, R., Batalha, F., & Nunes, A. J. B. (1999). Primeira

ocorrência de Craspedacusta sowerbyi Lankaster, 1880

(Cnidária, Limnomedusae) no Reservatório da UHE

Serra da Mesa, Goiás, Brasil (Caderno de Resumos,

VII Congresso Brasileiro de Limnologia, Vol. 2, pp.

487). Universidade Federal de Santa Catarina.

Deserti, M. I. (2016). Biodiversidad, biología y ecología

del género Hydra (Cnidaria: Hydrozoa) en ambientes

acuáticos continentales del sudeste de la Provincia de

Buenos Aires y algunos comentarios sobre el hidrozoo

colonial Cordylophora caspia [Unpublished doctoral

disssertation]. Universidad Nacional de Mar del Plata.

Deserti, M. I., & Zamponi, M. O. (2011). Hydra vulgaris

Pallas, 1766, (=Hydra attenuata) (Cnidaria; Hydro-

zoa) from the Los Padres Lagoon (Buenos Aires

province, Argentina). Revista Brasileira de Biociências,

9(4), 82–487.

Deserti, M. I., Zamponi, M. O., & Escalante, A. H. (2011).

The genus Hydra from Argentina. I. Hydra vulgaris

pedunculata subsp. nov. (Cnidaria, Hydrozoa). Revis-

ta Real Academia Galega de Ciencias, 30, 5–14.

Deserti, M. I., Zamponi, M. O., & Escalante, A. H. (2012).

The genus Hydra from Argentina. II. Hydra pseudo-

ligactis Hyman, 1931 (Cnidaria; Hydrozoa), a new

record. Revista Real Academia Galega de Ciencias,

31, 5–14.

Deserti, M. I., Escalante, A. H., & Acuña, F. H. (2015). New

record for the distribution of the colonial hydroid

Cordylophora caspia (Pallas, 1771) (Cnidaria: Hydro-

zoa) in Argentina. Check List, 11(1), 1515. https://doi.

org/10.15560/11.1.1515

Deserti, M. I., Grohmann, P., & Stampar, S. N. (2020).

Phylum Cnidaria. In C. Damborenea, D. C. Rogers

& J. H. Thorp (Eds.), Thorp and Covich’s Freshwa-

ter Invertebrates (Fourth Edition) Volume 5: Keys

to Neotropical and Antarctic Fauna (pp. 93–99).

Academic Press.

Dioni, W. (1968). Hydra (Chlorohydra) plagiodesmica sp.

nov., una hidra verde del río Salado, República Argen-

tina (Cnidaria, Hydrozoa). Physis, 28(76), 203–210.

Dioni, W. (1974). Noticia sobre un raro hidroide de agua

dulce de la Argentina y Uruguay, Calpasoma dactylop-

tera. Physis, 33(86), 147–150.

Domaneschi, O., & Coneglian, A. M. (1983, february 5).

Observações sobre o ciclo de vida de Calpasoma dac-

tiloptera e Mycrohydra ryderi (Cnidaria, Hydrozoa,

Limnomedusae) do Estado de São Paulo [Paper pre-

sentation]. X Congresso Brasileiro de Zoologia, Belo

Horizonte, Brazil.

Duggan, I. C., & Eastwood, K. R. (2012). Detection and

distribution of Craspedacusta sowerbii: observations

of medusae are not enough. Aquatic Invasions, 7,

271–275.

Dumont, H. J. (1994). The distribution and ecology of

the fresh- and brackish-water medusae of the world.

Hydrobiologia, 272, 1–12.

Failla, M. G., Serra, W. S., & Martínez, C. (2017). First

record of Craspedacusta sowerbii lankester, 1880

(Hydrozoa, Limnomedusae) in a natural freshwater

lagoon of Uruguay, with notes on polyp stage in

captivity. Brazilian Journal of Biology, 77(4), 665–672.

Figueroa, D., & de los Ríos, P. (2010) First report of Cras-

pedacusta sowerbii (Cnidaria) (Lankester, 1880) for

Patagonian waters (38° S, Chile): a possible presence

of invasive species and its potential ecological impli-

cations. Brazilian Journal Biology, 70(1), 227–228.

https://doi.org/10.1590/S1519-69842010000100032

Folino, N. C. (2000). The freshwater expansion and classifi-

cation of the colonial hydroid Cordylophora (Phylum

Cnidaria, Class Hydrozoa). In J. Pederson (Ed.),

18 Revista de Biología Tropical, ISSN: 2215-2075 Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

Marine Bioinvasions: Proceedings of the First National

Conference (pp. 139–144). Massachusetts Institute of

Technology Sea Grant College Program.

Folino-Rorem, N. C., Darling, J. A., & D’Ausilio, C. A. 2009.

Genetic analysis reveals multiple cryptic invasive spe-

cies of the hydrozoan genus Cordylophora. Biological

Invasions, 11, 1869–1882.

Fraire-Pacheco, K., Arancibia-Avila, P., Concha, J., Eche-

verría, F., Salazar, M. L., Figueroa, C., Espinoza, M.,

Sepúlveda, J., Jara-Zapata, P., Jeldres-Urra, J., & Vega-

Román, E. (2017). A new report of Craspedacusta

sowerbii (Lankester, 1880) in southern Chile. BioInva-

sions Records, 6(1), 25–31.

Froehlich, C. G. (1963). Ocorrência de forma polipóide de

Craspedacusta sowerbii Lank. (Limnomedusae) em

São Paulo. Anais da Academia Brasileira de Ciências,

35(3), 21–422.

Fuentes, R., Cárdenas, L., Abarzua, A., & Caputo, L. (2019).

Southward invasion of Craspedacusta sowerbii across

mesotrophic lakes in Chile: geographical distribution

and genetic diversity of the medusa phase. Freshwater

Science, 38, 193–202.

Fritz, G. B., Pfannkuchen, M., Reuner, A., Schill, R. O., &

Brümmer, F. (2009). Craspedacusta sowerbii, Lankes-

ter 1880 – Population dispersal analysis using COI

and ITS sequences. Journal of Limnology, 68, 46–52.

Gaggero, P. (1923). Cordylophora lacustris Allman en el Río

de la Plata. Annales de la Sociedad Científica Argenti-

na, 96, 264–268.

Galea, H. R. (2007). Cnidaria, Hydrozoa: latitudinal distri-

bution of hydroids along the fjords region of southern

Chile, with notes on the world distribution of some

species. Check List, 3(4), 308–320.

Gasith, A., Gafny, F., Hershkovitz, Y., Goldstein, H., & Galil,

B. S. (2011). The invasive freshwater medusa Craspe-

dacusta sowerbii Lankester, 1880 (Hydrozoa: Olin-

diidae) in Israel. Aquatic Invasions, 6(1), S147–S152.

Gliesch, R. (1930). A medusa de água doce Microhydra

spec. Egatea, 15, 145-148.

Grayson, R. F. (1971). The freshwater hydras of Europe. I.

A review of the European species. Archiv für Hydro-

biologie, 68, 436–449.

Grohmann, P. (2008). Bioincrustation caused by a hydroid

species in the turbine cooling system at the funil

hydroelectric power plant, Itatiaia, Rio de Janeiro,

Brazil. Naturalia, Rio Claro, 31, 16–21.

Guajardo, M. G., Sanchez, H. V., & Salvador Contreras,

Y. (1987) The cnidarians Craspedacusta sowerbyi

new-record and Cordylophora lacustris new-record

Hydrozoa for the Mexican fauna in Nuevo León.

Publicaciones Biológicas del Instituto de Investigaciones

Científicas, 2(2), 51–54.

Haddad, M. A., & Nakatani, K. (1996). Primeiro registro

de Cordylophora caspia (Pallas, 1771) (Cnidaria,

Hydroida) em águas continentais brasileiras [Paper

presentation]. XIV Congresso Brasileiro de Zoologia,

Porto Alegre, Brazil.

Hildebrand, S. F. (1939). The Panama Canal as a passa-

geway for fishes, with lists and remarks on the fishes

and invertebrates observed. Zoologica, 24(3), 15–45.

Holstein, T. & Emschermann, P. (1995). Cnidaria: Hydro-

zoa. Kamptozoa (Süßwasserfauna von Mitteleuropa

1/2,3). Gustav Fischer Verlag.

Holstein, T., Campbell, R., & Tardant, P. (1990). Identity

crisis. Nature, 346, 21–22.

Huarachi, R., & González, R. (2012). Hydra vulgaris Pallas,

1766 (Hydrozoa: Hydridae) como bioindicador de la

calidad de aguas del río Chili, Arequipa, Perú. The

Biologist, 10(2), 125–137.

iNaturalist. (2022, October 30). Comisión Nacional para el

Conocimiento y Uso de la Biodiversidad. http://www.

naturalista.mx

Infante, A., & Infante, O. (1994). Limnological Studies

in a Tropical Man-Made lake (Lagartijo Reservoir)

Venezuela. Internationale Revue Der Gesamten Hydro-

biologie Und Hydrographie, 79, 17–25. https://doi.

org/10.1002/iroh.19940790105

Jakovčev-Todorović D., Ðikanović V., Skorić S., & Cakić,

P. (2010). Freshwater jellyfish Craspedacusta sower-

byi Lankester, 1880 (Hydrozoa, Olindiidae)– 50

years’observations in Serbia. Archive of Biological

Sciences, 62(1), 123–127.

Jankowski, T. (2001). The freshwater medusae of the

world– a taxonomic and systematic literature study

with some remarks on other inland water jellyfish.

Hydrobiologia, 462, 91–113.

Jankowski, T., Collins, A. G., & Campbell, R. (2008). Global

diversity of inland water cnidarians. Hydrobiologia,

595, 35–40.

Jerónimo-Aguilar, S. (2013). Hidroides (Cnidaria: Hydro-

zoa) del Sistema Arrecifal Veracruzano, México [Doc-

toral disssertation, Universidad Nacional Autónoma

de México]. Repositorio Institucional de la UNAM.

https://repositorio.unam.mx/contenidos/334518

Jones, M. L., & Rützler, K. (1975). Invertebrates of the upper

chamber, Gatún Locks, Panama Canal, with emphasis

on Trochospongilla leidii (Porifera). Marine Biology,

33, 57–66.

Jormalainen, V., Honkanen, T., Vuorisalo, T., & Laihonen,

P. (1994). Growth and reproduction of an estuarine

population of the colonial hydroid Cordylophora

caspia (Pallas) in the northern Baltic Sea. Helgoländer

Meeresuntersuchungen, 48, 407–418.

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

Kaliszewicz, A. (2013). Is larger better in sit-and-wait pre-

dators? Competitive superiority in Hydra. Hydrobiolo-

gia, 714(1), 105–114.

Karaouzas, I., Zogaris, S., Lopes-Lima, M., Froufe, E.,

Varandas, S., Teixeira, A., & Sousa, R. (2015). First

record of the freshwater jellyfish Craspedacusta sower-

bii Lankester, 1880 in Greece suggests distinct Euro-

pean invasion events. Limnology, 16, 171–177.

Kramp, P. L. (1961). Synopsis of the medusae of the world.

Journal of the Marine Biological Association of the

United Kingdom, 40, 7–382.

Kuhl, G. (1947). Zeitrafferfilm-Untersuchungen tiber den

Polypen von Craspedacusta sowerbyi (ungeschlecht-

liche Fortpflanzung, Okologie, und Regeneration).

Abhandlungen der Senckenbergischen Naturforschen-

den Gesellschaft, 473, 1–72.

Lankester, E. R. (1880). On a new jelly–fish of the order Tra-

chomedusae, living in fresh water. Science, os-1(3),34.

https://doi.org/10.1126/science.os-1.3.34

Lenhoff, H. M. (1983). Hydra: Research methods. Plenum

Press.

Lewis, C., Migita, M., Hashimoto, H., & Collins, A. G.

(2012). On the occurrence of freshwater jellyfish in

Japan 1928–2011: eighty-three years of records of

mamizu kurage (Limnomedusae, Olindiidae). Pro-

ceedings of the Biological Society of Washington, 125,

165–179. https://doi.org/10.2988/11-31.1

Liotta J., & Wagner M. (2003). Actualización del diagnósti-

co de estado ambiental: Aspectos físicos y bioecológi-

cos (Proyecto n° ASR/B7-3100/IB/98/0143). MA BIO.

López-Ochoterena, E., & Madrazo-Garibay, M. (1989).

Protozoarios ciliados de México XXXIII. Estudio

biológico de algunas especies de las subclases Suctoria

y Peritrichia, asociados al hidrozoario Cordylophora

caspia (Pallas) en la Laguna de Mandinga, Veracruz.

Revista de la Sociedad Mexicana de Historia Natural,

40, 65–70.

Loyola e Silva, J., & Oliveira, S. (1988). O surto de Medusa

de água doce. Ciência Hoje, 7, 50–51.

Lytle, C. F. (1961). Patterns of budding in the freshwater

hydroid Craspedacusta. In H. M. Lenhoff & W. F. Loo-

mis (Eds.), Biology of Hydra and Some Other Coelente-

rates (pp. 317–336). University of Miami Press.

Mañé Garzón, F., & Carbonell, C. S. (1971). Sobre la medu-

sa de agua dulce Craspedacusta sowerbyi Rey-Lank,

1880, en el Uruguay. Boletín de la Sociedad Zoológica

del Uruguay, 1, 10.

Marchese, M., & Drago, I. E. (1983). Zoobentos de los prin-

cipales tributarios del río Paraná medio en el tramo

Goya-Diamante: Su relación con el cauce principal y

cauces secundarios. Revista de la Asociación de Cien-

cias Naturales del Litoral, 14(2), 95–109.

Marsden, J. E., & Hauser, M. (2009). Exotic Species in Lake

Champlain. Journal of Great Lakes Research, 35(2),

250–265. https://doi.org/10.1016/j.jglr.2009.01.006

Martínez, D. E., Iñiguez, A. R., Percell, K. M., Willner, J. B.,

Signorovitch, J., & Campbell, R. D. (2010). Phylogeny

and biogeography of Hydra (Cnidaria: Hydridae)

using mitochondrial and nuclear DNA sequences.

Molecular Phylogenetics and Evolution, 57(1), 403–

410. https://doi.org/10.1016/j.ympev.2010.06.016

Martins, A.V. (1941). Sobre a ocorrência da medusa de

água doce Craspedacusta sowerbyi Lankester, 1880,

em Minas Gerais. Revista Brasileira de Biologia, 1(2),

227–230.

Massaro, F. C., & Rocha, O. (2008). Development and

population growth of Hydra viridissima Pallas, 1766

(Cnidaria, Hydrozoa) in the laboratory. Brazilian

Journal of Biology, 68(2), 379–383.

Matthews, D. C. (1966). A comparative study of Craspeda-

custa sowerbyi and Calpasoma dactyloptera life cycles.

Pacific Sciences, 20, 246–259.

McClary, A. (1959). The effect of temperature on growth

and reproduction in Craspedacusta sowerbii. Ecology,

40, 158–162. https://doi.org/10.2307/1929945

Mendoza-Becerril, M. A., González-Muñoz, R., Jerónimo-

Aguilar, S., Tello-Musi, J. L., Genzano, G., Marques,

C., Melo-Merino, S. M., Mendoza, T., Castillo-Cupul,

R. E., Homá-Canche, P., Ugalde, D. & Simões, N.

(2022, September 21). Cnidarians from the Gulf of

Mexico and Mexican Caribbean at the “Colección de

Cnidarios del Golfo de México y Caribe Mexicano” at

the UMDI-Sisal, Facultad de Ciencias, UNAM, México.

GBIF. https://doi.org/10.15468/7s7j5n.

Minchin, D., Caffrey, J. M., Haberlin, D., Germaine, D.,

Walsh, C., Boelens, R., & Doyle, T. K. (2016). First

observations of the freshwater jellyfish Craspeda-

custa sowerbii Lankester, 1880 in Ireland coincides

with unusually high water temperatures. BioInvasions

Records, 5(2), 67–74.

Moreno-Leon, M. A., & Ortega-Rubio, A. (2009). First

record of Craspedacusta sowerbyi Lankester, 1880

(Cnidaria: Limnomedusae: Olindiidae) in Mexico

(Adolfo Lopez Mateos reservoir), with notes on their

feeding habits and limnological dates. Biological Inva-

sions, 11, 1827–1834.

Murillo, R. (1989). Presencia de Craspedacusta Sowerbyi en

el embalse de Arenal provincia de Guanacaste, Costa

Rica. Uniciencia, 6(1-2), 113–114.

Okolodkov, Y. B., Bastida-Zavala, R., Ibáñez, A. L., Chap-

man, J. W., Suárez-Morales, E., Pedroche, F., & Gutié-

rrez-Mendieta, F. J. (2007). Especies acuáticas no

indígenas en México. Ciencia y Mar, 11(32), 29–67.

Orrell, T. (2022, September 20). Natio-

nal Museum of Natural History Extant

20 Revista de Biología Tropical, ISSN: 2215-2075 Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

Specimen Records. GBIF. https://www.gbif.org/

dataset/821cc27a-e3bb-4bc5-ac34-89ada245069d

Oseguera, L. A., Alcocer, J., & Escobar, E. (2016). Macroin-

vertebrados bentónicos de dos lagos tropicales de alta

montaña en el volcán Nevado de Toluca, en la región

central de México. Hidrobiológica, 26(3), 419–432.

Oualid, J. A., Iazza, B., Tamsouri, N. M., El Aamri, F.,

Moukrim, A., & López González, P. J. (2019). Hidden

diversity under morphology-based identifications of

widespread invasive species: The case of the well-

known hydromedusa Craspedacusta sowerbii Lankes-

ter 1880. Animal Biodiversity and Conservation, 42(2),

301–316. https://doi.org/10.32800/abc.2019.42.0301

Paporello de Amsler, G. (1987). Fauna asociada a las raíces

de Eichhornia crassipes en una laguna del valle aluvial

del rio Paraná (“Los Matadores”, Santa Fe, Argentina).

Revista de La Asociación de Ciencias Naturales Del

Litoral, 181, 93–103.

Pavé, P. J., & Marchese, M. (2005). Benthic invertebrates

as indicators of water quality in urban rivers (Para-

ná-Entre Ríos, Argentina). Ecología Austral, 15(2),

183–197.

Pennak, R. W. (1989). Fresh-water Invertebrates of the Uni-

ted States: Protozoa to Mollusca (3rd ed.). John Wiley

& Sons.

Poggio Herrero, I. V., Mariame, M. P., Rodríguez, C., Fane-

lli, S. L., Porta, A., Fort, M., & Mastrantonio Garrigo,

G. (2014). Aplicación de bioensayos a la evaluación

ecotoxicológica de efluentes de tambo. Publicación

técnica - Estación Experimental Agropecuaria Anguil,

97, 8-2014, 64–66

Porter, C. E., & Schmitt, W. L. (1942). The first free-living

freshwater jellyfish from South America. Science,

96(2501), 515.

Potts, E. (1885). First use of name Microhydra ryderi. Scien-

ce, 5, 123.

Pouilly, M., Beek, S. G., Moraes M. R., & Ibañez, C. (2004).

Diversidad biológica en la llanura de inundación del

Río Mamoré. Importancia ecológica de la dinámica

fluvial. Centro de Ecología Simón I.

Quezada, A. E. (1969) Hallazgo de Craspedacusta sowerbyi

Lankester,1880 (Coelenterata, Hydrozoa), en Con-

cepción, Chile. Boletín de la Sociedad de Biología de

Chile, 45, 31–35.

Quezada, Q. & Aurora, E. (1973). Nueva localidad para

Chile de Craspedacusta sowerbyi Lankester, 1880

(Coelenterata, Hydrozoa). Boletín de la Sociedad de

Biología de Concepción, 46, 227.

Rahat, M., & Campbell, R. D. (1974). Nematocyte migra-

tion in the polyp and one-celled tentacles of the minu-

te fresh-water coelenterate Calpasoma dactyloptera.

Transactions of the American Microscopical Society,

93(3), 379–385. https://doi.org/10.2307/3225438

Reis Pereira, V. L. (2002). A limnologia e o gerenciamien-

to integrado do reservatório da usina hidreléctrica

Lusi Eduardo Magalhaes– UHE Lajeado, Tocantins

[Doctoral dissertation, Universidade de São Paulo].

Biblioteca Digital USP. https://teses.usp.br/teses/dis-

poniveis/18/18139/tde-25012017-151631/pt-br.php

Reisinger, E. (1957). Zur Entwicklungsgeschichte und Ent-

wicklungsmechanik von Craspedacusta (Hydrozoa,

Limnotrachylina). Zeitschrift für Morphologie und

Ökologie der Tiere, 45(6), 656–698.

Restello, R. M., Didone, M. A., & Carus, C. (2015). Medusa

de água doce: Craspedacusta sowerbii (Lankester,

1880) (Hydrozoa, Limnomedusae) no Alto Uruguai

do Rio Grande do Sul. Perspectiva, 39(145), 179–182.

Richard, E. (1990). La curiosa medusita de agua dulce.

Subaquatica, 2(6), 28–29.

Ringuelet, R. A. (1950). La medusa de agua dulce Craspeda-

custa sowerbyi Lank. en la Argentina. Notas del Museo

de La Plata, Zoología, 134(15), 133–150.

Ringuelet, R. A., & Olivier, S. (1954). Anotaciones sobre

Cordylophora caspia (Pallas) en la Argentina (Hydro-

zoa). Notas del Museo de La Plata, Zoología, 147(17),

67–70.

Rioja, E. (1959). Estudios hidrobiológicos. XII: Hallazgo de

la Cordylophora caspia (Pallas) (hidroideo gimnoblás-

tido en la laguna de Mandinga, Veracruz). Anales del

Instituto de Biología, Universidad Nacional Autónoma

de México, 30(1–2), 151–157.

Rivera De la Parra, L., Sarma, S. S. S., & Nandini, S. (2016).

Effects of predation by Hydra (Cnidaria) on clado-

cerans (Crustacea: Cladocera). Journal of Limnology,

75(S1), 39–47.

Roch, F. (1924). Experimentelle Untersuchungen an Cor-

dylophora caspia (Pallas) [=lacustris Allman] über

die Abhängigkeit ihrer geographischen Verbreitung

und ihrer Wuchsformen von den physikalisch-che-

mischen bedingungen des umgebenden Mediums.

Zeitschrift für Morphologie und Ökologie der Tiere,

2, 350–426.

Roos, P. J. (1979). Two-stage life cycle of a Cordylophora

population in the Netherlands. Hydrobiologia, 62(3),

231–239.

Russell, F. S. (1953). The medusae of the British Isles II:

Anthomedusae, Leptomedusae, Limnomedusae, Tra-

chymedusae and Narcomedusae. Cambridge Univer-

sity Press.

Savaris, M., Lampert, S., & Haddad, M. A. (2013). Craspe-

dacusta cf. sowerbii Lankester, 1880 (Cnidaria: Hydro-

zoa: Limnomedusae): New record for the middle

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 71(S3): e56470, agosto-diciembre 2023 (Publicado Set. 22, 2023)

plateau region of the state of Rio Grande do Sul, Bra-

zil. Check List, 9(44), 906–908.

Sawaya, M. P. (1957). Ocorrencia de Craspedacusta sowerb-

yi (medusa de água doce) no Estado do Rio de Janeiro.

Ciência e Cultura, 9(2), 77.

Schmid-Araya, J. M. & Zúñiga L. R. (1992). Zooplank-

ton community structure in two Chilean reservoirs.

Archiv fur Hydrobiologie, 123, 305–335.

Schubart, O. (1938). Considerações sobre as investigações

nas águas de Pernambuco. Arquivos do Instituto de

Pesquisas Agronómicas Pernambuco, 1, 26–57.

Schulze, P. (1927). Zur Kenntnis und geographischen Ver-

breitung der Süsswasserpolypen. Zoologischer Anzei-

ger, 74, 129–140.

Schuchert, P. (2022). World Hydrozoa Database. Retrieved

March 11, 2023, from https://www.marinespecies.

org/hydrozoa

Schwartz, S., Hann, B. J., & Hebert, P. D. (1983). The fee-

ding ecology of Hydra and possible implications in

the structuring of pond zooplankton communities.

Biological Bulletin, 164, 136–142.

Schwarzbold, A., Volkmer-Ribeiro, C., Vasconcelos, M. C.,

Schneck, F., & Sponchiado, M. (2010). Ocorrência de

Craspedacusta sowerbii (Hydrozoa: Limnomedusae)

(Lankester, 1880) no reservatório da Usina Hidrelé-

trica 14 de Julho, Rio Grande do Sul, Brasil. Revista

Brasileira de Biociências, 8(3), 305–307.

Schwentner, M., & Bosch, T. C. (2015). Revisiting the age,

evolutionary history and species level diversity of the

genus Hydra (Cnidaria: Hydrozoa). Molecular Phylo-

genetics and Evolution, 91, 41–55.

Silva, W. M., & Roche, K. F. (2007). Occurrence of the

freshwater jellyfish Craspedacusta sowerbii (Lankes-

ter, 1880) (Hydrozoa, Limnomedusae) in a calca-

reous lake in Mato Grosso do Sul, Brazil. Biota

Neotropica, 7(1), 173–176. https://doi.org/10.1590/

S1676-06032007000100028

Silveira, F., & Boscolo, H. K. (1996). Primeira oco-

rrencia de Cordylophora caspia (Pallas, 1771)

(Hydrozoa, Clavidae) para o Estado de Sao Paulo

[Paper presentation].

XIV Congresso Brasileiro de Zoologia, Porto Alegre, Brazil.

Silveira, F., Gómez, C. S., & Silva, Z. D. (1997). New species

of Hydra Linnaeus, 1758 (Cnidaria, Hydrozoa) from

Southeastern Brazil. Boletim do Museum Nacional,

373, 1–15.

Smith, F. (1925). Fresh-water medusae in the Panama Canal

zone. Science, 61, 588–589.

Souza, M., & Ladeira, M. (2011). Craspedacusta sowerbyi

Lankester, 1880 (Cnidaria: Hydrozoa: Olindiidae):

New record in Minas Gerais state, Brazil. Check List,

7(5), 610–611. https://doi.org/10.15560/7.5.610

Spira, M. (1964). Observations of Calpasoma dactyloptera

(Trachylina). Israel Journal of Zoology, 13(3), 134.

Trochine, C., Balseiro, E. G., & Modenutti, B. E. (2008).

Zooplankton of fishless ponds of Northern Patagonia:

insights into predation effects of Mesostoma ehren-

bergii. International Review of Hydrobiology, 93(3),

312–327. https://doi.org/10.1002/iroh.200711011

Trochine, C., Modenutti, B. E., & Balseiro, E. G.

(2009). Chemical signals and habitat selection by

three zooplankters in Andean Patagonian ponds.

Freshwater Biology, 54, 480–494. https://doi.

org/10.1111/j.1365-2427.2008.02125.x

Vannucci, M., & Tundisi, J. (1962). Las medusas existentes

en los museos de La Plata y Buenos Aires. Comu-

nicaciones del Museo Argentino de Ciencias Natura-

les Bernardino Rivadavia, Ciencias Zoológicas, 3(8),

203–215.

Wagner, R. (1833). Ueber eine neue im adriatischen Meere

gefundene Art von nackten Armpolypen und seine

eigenthümliche Fortpflanzungsweise. Isis, 1833,

256–260.

Wedler, E. (2017). Hidroides del Mar Caribe con énfasis en la

región de Santa Marta, Colombia. Instituto de Inves-

tigaciones Marinas y Costeras (Serie de Publicaciones

generales del INVEMAR.