Revista de Biología Tropical, ISSN: 2215-2075, Vol. 73(S1): e63625, enero-diciembre 2025 (Publicado Mar. 03, 2025)

Diversity of freshwater crab: new distributional data for four species

(Decapoda: Pseudothelphusidae) from Meso- and South American countries

Célio Magalhães 1,2; https://orcid.org/0000-0003-4858-2575

Ingo S. Wehrtmann 3,4; https://orcid.org/0000-0002-6826-7938

1. Laboratory of Bioecology and Crustacean Systematics (LBSC), Department of Biology, Faculty of Philosophy,

Sciences and Letters at Ribeirão Preto (FFCLRP), University of São Paulo (USP), São Paulo, Brazil; celiomag@usp.br

(*Correspondence)

2. Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Brazil.

3. Museo de Zoología of the Centro de Investigación en Biodiversidad y Ecología Tropical (CIBET), Universidad de Costa

Rica, San José, Costa Rica; ingo.wehrtmann@ucr.ac.cr

4. Centro de Investigación en Ciencias del Mar y Limnología (CIMAR), Universidad de Costa Rica, San José, Costa Rica.

Received 07-III-2024. Corrected 30-VIII-2024. Accepted 24-I-2025.

ABSTRACT

Introduction: The Pseudothelphusidae is a very diverse family of primary freshwater crabs widely distributed

throughout the Neotropical region, but the true extent of the geographic distribution of several species is poorly

known because many of them occur in very remote areas with only a single or very few records available.

Objective: Here we present new country records for four species of pseudothelphusid crabs from Meso- and

South American countries.

Methods: The data about the geographic distribution are based on specimens deposited in crustacean collections

of institutions from Brazil, Germany, and USA; illustrations of the male first gonopod were prepared in stereo-

microscope equipped with a camera lucida.

Results: Occurrence records of Phygiopilus acanthophallus from Mexico, Fredius stenolobus from Guyana, and

Kunziana irengis from Brazil are published for the first time, and the occurrence of Raddaus mertensi from

Honduras is confirmed. Comments on the morphology of the male first gonopod of each species are given,

their range extensions are discussed, and the importance of these new records for conservation assessments is

highlighted.

Conclusions: The new data expand the area of occurrence of these four species of Pseudothelphusidae freshwater

crabs, providing new data that are relevant for taxonomic and biogeographical studies as well as for the develop-

ment of better regional and national assessments of the conservation status of the aquatic fauna.

Key words: Amazonia; biogeography; conservation; distribution records; geographical range; Guayana Shield;

Neotropical region; Kingsleyinae; Raddausinae.

RESUMEN

Diversidad de cangrejos de agua dulce: nuevos datos de distribución para cuatro especies

(Decapoda: Pseudothelphusidae) de países de Meso y Sudamérica

Introducción: Pseudothelphusidae es una familia muy diversa de cangrejos primarios de agua dulce ampliamen-

te distribuida por toda la región Neotropical, pero la verdadera extensión de la distribución geográfica de varias

especies es poco conocida porque muchas de ellas viven en zonas muy remotas de las que sólo se dispone de un

único registro o de muy pocos.

https://doi.org/10.15517/rev.biol.trop..v73iS1.63625

SUPPLEMENT

2Revista de Biología Tropical, ISSN: 2215-2075 Vol. 73(S1): e63625, enero-diciembre 2025 (Publicado Mar. 03, 2025)

INTRODUCTION

Freshwater covers less than 1 % of the

world’s surface area but harbors almost 10 %

of all described species (Darwall et al., 2018;

Dijkstra et al., 2014; Dudgeon et al., 2006;

Mittermeier et al., 2010). Despite the indisput-

able importance of freshwater ecosystems in

economic, cultural, aesthetic, scientific, and

educational terms (see Dudgeon et al., 2006),

we are facing a freshwater biodiversity crisis

due to catastrophic declines in freshwater spe-

cies and the degradation of these hydrological

ecosystems (Darwall et al., 2018; Harrison et

al., 2018; World Wildlife Fund [WWF], 2020).

The Living Planet Report 2020 revealed a 94

% decline of the Living Planet Index for Latin

America and the Caribbean, the most striking

result observed in any region (WWF, 2020).

True or primary freshwater crabs (see

Cumberlidge & Ng, 2009; Yeo et al., 2008) form

with approximately 1 400 species an important

part of the freshwater biodiversity in tropi-

cal and subtropical regions around the world

(Yeo et al., 2008). The freshwater crab species

diversity in the Neotropics — 311 species in

three families (Trichodactylidae, Epiloboceri-

dae and Pseudothelphusidae) — is only sur-

passed by that of east and southeastern Asia

(Cumberlidge et al., 2014). According to the

IUCN Red List conservation assessment, 34 %

of the pseudothelphusids have an elevated risk

of extinction, and 56 % of these species are too

poorly known to assess (see Cumberlidge et

al., 2014). Moreover, a recent assessment of the

freshwater crabs in Colombia, which harbors

the highest number of species in the Neo-

tropics, revealed that pseudothelphusids are

the most threatened freshwater crab species in

this country (Acevedo-Alonso & Cumberlidge,

2021, Acevedo-Alonso & Cumberlidge, 2022).

These data highlight the urgent need to obtain

additional information about freshwater crab

species inhabiting the Neotropics, especially

about Pseudothelphusidae.

The Pseudothelphusidae is a very diverse

family of primary freshwater crabs widely dis-

tributed throughout the Neotropical region,

but the true extent of the geographic distribu-

tion of several species is poorly known because

many of them occur in very remote areas with

only a single or very few records available. For

such species, therefore, all data relating to new

occurrences are relevant as they are important

for both taxonomic and biogeographic studies

as well as for the development of regional and

national assessments of the conservation status

of the fauna. Here, we present new country

records for three species of pseudothelphusid

crabs: Phygiopilus acanthophallus Smalley, 1970

Objective: Aquí presentamos nuevos registros nacionales para cuatro especies de cangrejos pseudotelfusidos de

países de Meso- y Sudamérica.

Métodos: Los datos sobre la distribución geográfica se basan en especímenes depositados en colecciones de crus-

táceos de instituciones de Brasil, Alemania y Estados Unidos; se prepararon ilustraciones del primer gonópodo

masculino en un microscopio estereoscópico equipado con una cámara lúcida.

Resultados: Se publican por primera vez los registros de ocurrencia de Phygiopilus acanthophallus en México,

Fredius stenolobus en Guyana y Kunziana irengis en Brasil, y se confirma la presencia de Raddaus mertensi en

Honduras. Se dan comentarios sobre la morfología del primer gonópodo masculino de cada especie, se discuten

sus extensiones de distribución y se destaca la importancia de estos nuevos registros para las evaluaciones de

conservación.

Conclusiones: Los nuevos datos de la distribución geográfica amplían las áreas de ocurrencia de estas cuatro

especies de cangrejos dulceacuícolas de la familia Pseudothelphusidae, proporcionando nuevos datos que son

relevantes para estudios taxonómicos y biogeográficos, así como para el desarrollo de mejores evaluaciones regio-

nales y nacionales del estado de conservación de la fauna acuática.

Palabras clave: Amazonia; biogeografía; conservación; registros de distribución; rango geográfico; escudo de

Guayana; región Neotropical; Kingsleyinae; Raddausinae.

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 73(S1): e63625, enero-diciembre 2025 (Publicado Mar. 03, 2025)

from Mexico and two from South Ameri-

can countries: Fredius stenolobus Rodríguez

& Suárez, 1994 from Guyana and Kunziana

irengis (Pretzmann, 1971) from Brazil, as well as

the confirmation of the occurrence of Raddaus

mertensi (Bott, 1956) in Honduras. Consider-

ing that accurate information on the geographic

occurrence and distribution of these species is

scarce, here we discuss these new records and

range extensions and highlight the importance

of such data for the conservation assessment of

freshwater crabs in the Neotropics.

MATERIALS AND METHODS

The new records are based on specimens

that are preserved in ethanol 70 % and deposited

at the following institutions: Forschungsinstitut

und Naturmuseum Senckenberg (SMF), Frank-

furt am Main, Germany; Instituto Nacional

de Pesquisas da Amazônia (INPA), Manaus;

Museu de Zoologia, Universidade de São Paulo

(MZUSP), São Paulo, Brazil; and Nation-

al Museum of Natural History, Smithsonian

Institution (USNM), Washington D.C., U.S.A.

Measurements of carapace are presented in

millimeters; carapace width (cw) was mea-

sured across the carapace at its widest point,

and carapace length (cl) was measured along

the midline, from the frontal to the posterior

carapace margin. The abbreviation “G1” refers

to the male first gonopod and “coll.”/“colls.” to

collector(s). The Portuguese word “igarapé”

means creek or a small forest stream. The only

locality without geographic coordinates origi-

nally informed in the label was tentatively geo-

referenced using Google Earth® software and

these coordinates are given in brackets. Line

drawings were made by CM using a Wild M8

(Wild, Heerbrugg, Switzerland) stereomicro-

scope equipped with a drawing tube attached,

then scanned and edited in Adobe Photoshop®

CS 2 software. The plates were mounted in

CorelDraw® X3 software.

RESULTS

Distributional data of four species of pseu-

dothelphusid crabs, two of Raddausinae and

two of Kingsleyinae, are presented for four

Meso- and South American countries: P. ac an -

thophallus in southeastern Mexico, R. mertensi

in western Honduras, F. stenolobus in west-cen-

tral Guyana, and K. irengis in northern Brazil.

Raddausinae Álvarez, Ojeda, Souza-Carvalho,

Villalobos, Magalhães, Wehrtmann

& Mantelatto, 2020

Phrygiopilus acanthophallus Smalley, 1970

(Fig. 1A)

Material examined: 2 males (cw 11.8,

cl 8.0; cw 24.3, cl 15.2), 2 females (cw 19.5,

cl 11.3; damaged), USNM 1180974, Mexico,

Chiapas, near San Jose [San Jose de las Pal-

mas, ~16°08’15”N 91°38’27”W], 28 miles ESE

of Comitán [Comitán de Domínguez], 7–20.

IV.1950, F.A. Pitelka coll.

Diagnosis: See Smalley (1970) and Rodri-

guez (1982).

Distribution: Guatemala (Alta Verapaz,

Baja Verapaz, Zacapa) (Rodriguez, 1982; Smal-

ley, 1970; Wehrtmann et al., 2016) and Mexico

(present study).

Remarks: The identity of present speci-

mens was determined by Martha R. Cam-

pos in June 1997, but this information has

never been formally published (http://n2t.

net/ark:/65665/3f6df1a83-408a-4140-8897-

1ae4806b9974).

The G1 of the largest male from Chiapas,

Mexico (USNM 1180974) resembles that of the

holotype regarding its general morphology and,

particularly, the proportions of the supra-apical

process (Fig. 1A).

Raddaus mertensi (Bott, 1956)

(Fig. 1B, Fig. 1C)

Material examined: 1 male (cw 35.1, cl

22.5), 1 female (cw 24.5, cl 16.6), SMF 31690,

Honduras, Ocotepeque, Guarin, cerro El Pital,

14°23.92’N 89°09.19’W, 14.V.1997, G. Köhler

coll.

Diagnosis: See Rodriguez (1982).

Distribution: Guatemala (Chiquimula)

(Wehrtmann et al., 2016), El Salvador (Santa

4Revista de Biología Tropical, ISSN: 2215-2075 Vol. 73(S1): e63625, enero-diciembre 2025 (Publicado Mar. 03, 2025)

Ana) (Bott, 1956), and Honduras (Ocotepeque)

(Acevedo-Alonso & Cumberlidge, 2022; pres-

ent study).

Remarks: The occurrence of R. mertensi

in Honduras has already been reported by

Acevedo-Alonso & Cumberlidge (2022) in a

study on the conservation status of mountain

species. However, these authors neither speci-

fied the distributional data of the specimen(s)

nor reported the voucher material on which the

record was based. The record presented herein

confirms the occurrence of the species in the

Ocotepeque department of Honduras.

The G1 of the specimen from Honduras

is similar to that of the holotype except for the

crenulation in the distal margin of the mesial

process, which is slightly more pronounced

in the Honduras specimen; furthermore, the

small, rounded protuberance on the cephalic

surface of the mesial process, which is present

Fig. 1. Phrygiopilus acanthophallus, USNM 1180974, left male first gonopod, entire stem in mesial view (A); Raddaus

mertensi, SMF 31690, right male first gonopod, distal portion in mesocaudal view (B) and laterocephalic view (C); Fredius

stenolobus, MZUSP 24496, left male first gonopod, distal portion in mesocaudal view (D); Kunziana irengis, INPA 2565, left

male first gonopod, distal portion in mesial view (E) and caudolateral view (F).

Revista de Biología Tropical, ISSN: 2215-2075, Vol. 73(S1): e63625, enero-diciembre 2025 (Publicado Mar. 03, 2025)

in the G1 of the holotype, is barely noticeable in

the Honduras specimen (Fig. 1C).

Kingsleyinae Bott, 1970

Fredius stenolobus Rodríguez & Suárez, 1994

(Fig. 1D)

Material examined: 1 male (cw 42.2, cl

28.3), MZUSP 24492, Guyana, Potaro-Siparuni,

creek tributary of Kuribrong river, 05º27’N

59º31’W, 28.III.2011, F.C.T. Lima coll.

Diagnosis: See Rodríguez & Suárez (1994).

Distribution: Venezuela (Bolívar)

(Magalhães & Pereira, 2003; Mora-Day & Blan-

co-Belmonte, 2008; Rodríguez & Suárez, 1994),

Brazil (Roraima) (Zanetti et al., 2018), and

Guyana (present study).

Remarks: The G1 of the present specimen

is partially damaged, with a fissure at the base

of the apical complex, just between the mesial

process and the cephalic spine (Fig. 1D). Even

so, it can be seen that the G1 morphology of

the Guyana specimen is very similar to that of

specimens from the Orinoco (see Rodríguez

& Campos, 1998: 766, fig. 2A, B) and Amazon

basins (see Zanetti et al., 2018: 4, fig. 1G). The

only noticeable difference is in the G1 mar-

ginal process: in the present specimen, there is

a small subdistal concavity whereas this con-

cavity is very shallow in the specimen from the

Amazon basin and indistinct in the specimen

from the Orinoco basin.

Kunziana irengis (Pretzmann, 1971)

(Fig. 1E, Fig. 1F)

Material examined. 1 male (cw 23.0, cl

15.3), 1 female (soft carapace), MZUSP 45521,

Brazil, Roraima, Uiramutã, Serra do Sol, Parque

Nacional do Monte Roraima (= Mount Ror-

aima National Park), igarapé Caramambai, near

the bridge to the community Caramambatai,

05º07’58.8”N 60º35’08.8”W, 1005 m elev., col-

lected with dip net, captured while copulating,

10.XII.2019, J. Zuanon, G.T. Vilara and R. Bold-

rini colls.; 1 male (cw 13.8, cl 8.4) 1 female (cw

19.5, cl 12.5), MZUSP 45522, Brazil, Roraima,

Uiramutã, Serra do Sol, Parque Nacional do

Monte Roraima (= Mount Roraima Nation-

al Park), unnamed 2nd/3rd order stream, on

the trail to the Ingarikó farm, 05º06’52.1”N

60º36’34.0”W, 1003 m elev., 05.XII.2019, J.

Zuanon and D.A. Bastos colls.; 2 males (cw

20.0, cl 14.0; cw 21.3, cl 14.3) 1 female (cw 15.0,

cl 10.5), CCDB 7811, Brazil, Roraima, Uira-

mutã, Serra do Sol, Parque Nacional do Monte

Roraima (= Mount Roraima National Park),

unnamed 3rd order stream, 05º07’07.5”N

60º36’21.0”W, 1043 m elev., 30.XI.2019, J.

Zuanon and D.A. Bastos colls.; 1 male (cw

30.5, cl 19.7) 2 females (cw 23.3, cl 15.4; cw

30.3, cl 19.2), INPA 2565, Brazil, Roraima,

Uiramutã, Serra do Sol, Parque Nacional do

Monte Roraima (= Mount Roraima Nation-

al Park), 05º07’36.2”N 60º35’36.7”W, 1008 m

elev., 29.XI.2019, J. Zuanon and D.A. Bastos

colls.; 1 female (cw 22.8, cl 16.2), INPA 2566,

Brazil, Roraima, Uiramutã, Serra do Sol, Parque

Nacional do Monte Roraima (= Mount Rorai-

ma National Park), unnamed 1st order stream,

at the beginning of the trail to the Ingarikó

farm, 05º07’37.7”N 60º35’58.6”W, ~1000 m

elev., 30.XI.2019, J. Zuanon and D.A. Bastos

colls.; 2 females (cw 22.6, cl 15.1; cw 22.7, cl

15.7), INPA 2567, Brazil, Roraima, Uiramutã,

Serra do Sol, Parque Nacional do Monte Rorai-

ma (= Mount Roraima National Park), igarapé

Sokopi (3nd/4th order stream), 05º07’27.7”N

60º35’49.3”W, 1005 m elev., 01.XII.2019, J.

Zuanon and D.A. Bastos colls.

Diagnosis: See Magalhães et al. (2009).

Distribution. Guyana (Potaro-Siparuni)

(Magalhães et al., 2009; Pretzmann, 1971) and

Brazil (Roraima) (present study).

Remarks. The monospecific genus Kun-

ziana is characterized by a very unusual G1

morphology in which the apical processes

exhibit a combined strong twist in cephalic

direction with a longitudinal bending towards

the basal portion of the stem, causing the apical

field of spines to face downwards (Magalhães et

al., 2009: 42, fig. 1E–I). Such peculiar morphol-

ogy can also be seen in the G1 of the Brazilian

specimen of K. irengis examined herein, which,

however, exhibits a slightly more developed

patch of apical spinules on the distal portion

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of the caudal surface, and the apical plate is

not so distinctly bilobed (Fig. 1F). These small

differences could be attributed to the differ-

ent sizes of the specimens examined or intra-

specific variability.

DISCUSSION

Species distribution: This is the first pub-

lished record of P. acanthophallus from Mexico.

The species was previously known only from

Guatemala, in the departments of Alta Verapaz

(Rodriguez, 1982; Smalley, 1970) and Zacapa

(Wehrtmann et al., 2016), from the Caribbean

Sea drainage area. The location of the present

record in the department of Chiapas is located

in the upper-median portion of the Usumacinta

River basin, which empties into the Gulf of

Mexico. The species, therefore, has a distribu-

tion that encompasses river systems draining

into two versants. This new occurrence in

Chiapas, near the border with Guatemala, also

suggests that the species must have a wider

distribution in northwestern Guatemala, since

it would also be expected to occur in the upper

portion of the Usumacinta River basin.

Documented records of R. mertensi were

so far available only from its type locality, the

Department of Santa Ana, in northwestern El

Salvador (Bott, 1956) and from the Department

of Chiquimula, eastern Guatemala, in the Pacif-

ic versant (Wehrtmann et al., 2016). Although

the occurrence of the species has already been

mentioned from Honduras (Acevedo-Alonso &

Cumberlidge, 2022), this is the first document-

ed record from the country, and such occur-

rence is not unexpected since the three known

occurrences of the species are situated relatively

close to each other in the region where the

borders of the three countries converge, all in

aquatic systems of the Pacific drainage.

Fredius stenolobus had already been record-

ed from the Caroni and Caura River basins in

the state of Bolívar, Venezuela (Magalhães &

Pereira, 2003; Mora-Day & Blanco-Belmonte,

2008; Rodríguez & Suárez, 1994), which are

part of the Orinoco River basin, and from the

Branco River basin in the state of Roraima,

Brazil (Zanetti et al., 2018), an affluent of the

Negro River, one of the main northern tributar-

ies of the Amazon basin. Its occurrence in the

Kuribrong River, an affluent of the Potaro River,

which is part of the Essequibo River basin in

west-central Guyana, is the first record of the

species from this country. The present new

record, therefore, reveals that F. stenolobus has

a distribution that covers three different river

basins draining the Guayana Shield region in

northern South America.

Kunziana irengis has been originally found

in the Guyanase side of the Maú/Ireng River

basin (Magalhães et al., 2009; Pretzmann, 1971),

the river that delineates the border between

western Guyana and Brazil. The present record

in creeks that are tributaries of the Contigo

River (tributary of the Surumu → Tacutu →

Branco → Negro → Amazon Rivers) confirms

that it also occurs in Brazilian territory, as

suggested by Magalhães et al. (2009). Both the

Contigo River and the Maú/Ireng River, which

also flows into the Tacutu River, are some of

the northernmost tributaries of the Amazon

basin. Although the known occurrences of the

species in Guyanese territory are located on

the southern flank of the Wokomung Massif,

whose streams drain into the Maú/Ireng River

basin, Magalhães et al. (2009) did not rule out

the possibility that the species is also present

in the Essequibo River basin, in streams that

form the headwaters of the Potaro River in the

northern portion of the aforementioned massif.

The presence of common elements of the

aquatic fauna between the Essequibo and Bran-

co River basins, as it is the case of F. stenolobus

and K. irengis reported herein, as well as for

other species of pseudothelphusid crabs (Man-

telatto et al., 2022), can be understood in the

context of the hydrogeomorphologic complex

history of the region. This region was drained

by the Proto-Berbice River basin that flew

during Late Cretaceous to Early Quaternary

from the southwest of the state of Roraima to

the northeast of present-day Guyana. Tectonic

and climatic events during the Plio-Pleistocene,

however, promoted a rearrangement of the

basin, especially the southward reversion of the

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Branco River and its entire northern catchment

area, including the Maú/Ireng river drainage,

into the Amazon basin, with a still existing con-

nection area, the Rupununi Portal, a wetland

region between the Tacutu and upper Esse-

quibo rivers (Cremon et al., 2016; Ferreira et

al., 2007; Lujan & Armbruster, 2011; Schaefer

& Vale, 1999).

Conservation assessment: The IUCN

global conservation assessment carried out in

2008 contains information only for three of

the four species treated in this contribution:

P. acanthophallus and R. mertensi were listed

as “Vulnerable”, while F. stenolobus was clas-

sified as “Least Concern”. The fourth species,

K. irengis, was not included in the 2008 IUCN

global assessment, since it was considered as

incertae sedis and as a non-valid species (C.

Magalhães, personal observation, Sept. 2007).

Only after this assessment, Magalhães et al.

(2009) confirmed Kunziana as a valid genus

and redescribed K. irengis. In the case of the

three freshwater crab species included in the

IUCN conservation assessment, all of them

are lacking information about population size,

population trends, and abundance. Moreover,

their assessment was based on only three (R.

mertensi and F. stenolobus) or four (P. a c a n -

thophallus) locations. In all three cases, the

results of our study not only add new geo-

graphical reports/locations, but also include a

new country previously not recorded for the

species. Such information is important since

it is the basis for the calculation of two evalu-

ation criteria (Extent of occurrence and Area

of occupancy) used for the assessment of the

IUCN categories (International Union for Con-

servation of Nature [IUCN], 2012). Moreover,

regular updating of the data is essential, as

shown by the example of Colombia, the country

with the highest number of freshwater crab in

the Neotropics: between the first (2008) and

the latest (2018) assessment, the percentage

of threatened species in Colombia showed a

dramatic increase from 26 % in 2008, to 34

% in 2015, to 62 % in 2018 (Acevedo-Alonso

& Cumberlidge, 2021). Therefore, additional

studies are constantly necessary not only to

update and expand our knowledge about the

different freshwater crab species but also to

broaden and improve the information about

threats affecting these macroinvertebrates.

A relatively high number of data-defi-

cient species could lead to underestimations of

the numbers of threatened freshwater species

(Cumberlidge et al., 2014). In the case of K.

irengis, this species has not even been assessed

yet and only few specimens have been col-

lected so far. The limited information available

about the habitat of this species indicates that

it occurs in clean rocky mountain streams

with elevations ranging from 1 077 to 1 485 m

(Magalhães et al., 2009). Just as in Colombia

(see Acevedo-Alonso & Cumberlidge, 2021;

Acevedo-Alonso & Cumberlidge, 2022), these

montane environments might be threatened

by increasing rates of deforestation, pollution,

and human population growth. Serra do Sol, in

the setentrional region of the state of Roraima,

Brazil, is a mountainous region covered by

savannah and forest situated within the Rapo-

sa-Serra do Sol Indigenous Land inhabited by

indigenous people from several ethnic groups,

an area that has experienced intense political

conflicts between developers and the native

population due to the region’s mineral, agricul-

tural, and tourist potential (Lauriola, 2003; Sar-

tori & Bethonico, 2018). Therefore, there is an

urgent need to obtain additional information

about K. irengis and to identify current threats

to its habitat to develop adequate conservation

measures for this species.

Although these new records only slightly

expand the geographic distribution areas of

these four Pseudothelphusidae freshwater crab

species, they provide relevant new data for

taxonomic and biogeographic studies, as well

as for the development of better regional and

national assessments of the conservation status

of the aquatic fauna.

Ethical statement: the authors declare

that they all agree with this publication and

made significant contributions; that there is

no conflict of interest of any kind; and that we

8Revista de Biología Tropical, ISSN: 2215-2075 Vol. 73(S1): e63625, enero-diciembre 2025 (Publicado Mar. 03, 2025)

followed all pertinent ethical and legal proce-

dures and requirements. All financial sources

are fully and clearly stated in the acknowledg-

ments section. A signed document has been

filed in the journal archives.

ACKNOWLEDGEMENTS

We thank Jansen Zuanon and Douglas

A. Bastos for making available the crustacean

material collected during their expedition to

Serra do Sol for our study. CM also acknowl-

edges the assistance of Marcos Tavares

(MZUSP), the late Michael Türkay (SMF), and

Rafael Lemaitre and Karen Reed (USNM) dur-

ing study visits to their respective institutions.

ISW would like to acknowledge the support of

the Universidad de Costa Rica through project

No. C2721. We also acknowledge the valuable

comments of two anonymous reviewers, which

contributed to improving the manuscript.

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