Abstract
Structural changes of the soft-bottom community of a tropical intertidal mud flat (more than 30% silt + clay) in the Gulf of Nicoya, Costa Rica, were evaluated from February, 1984 through February, 1985. Core samples (core area: 17.7 cm2) were collected, at semi-monthly intervals, within a 484 m 2 area and to a depth of 15 cm into the sediment. Samples were preserved in 10% buffered formalin in sea water stained with Rose Bengal. Organisms retained on a 500 mieron mesh sieve were considered as macrofauna.
A total of 92 species of macro-invertebrates and the gobiid fish, Gobionellus sagitulla (Gunther) were collected. The community was numerically dominated by deposit feeders. The ostracod, Cyprideis pacifica Hartmann and an undescribed cumacean (Bodotriinae) were the most common organisms found, representing 4 3.4% of the total. The polychaetes, Mediomastus californiensis Hartman, Paraprionospio pinnata (Ehlers), and Lumbrineris tetraura (Schmarda) accounted for 19.2% of the total. An unidentified flatworm (Turbellaria) represented 8.3% of the total number of individuals. Mean density of macro fauna (± 1 SO) was 13,827 ± 10, 1 85 individuals per m2. Diversity (H’) ranged from 1.75 to 3.36 per date (28 cores) and equitability (Evenness) ranged from 0.48 to 0.87.
Cluster, principal components, and multiple discriminant analyses revealed a seasonal pattern of the community (dry and rainy seasons). Most species appear to reproduce throughout the year. Peaks of reproductive activity, however, were detected for a group of species.
In addition to biological and physical disturbance, spatial and temporal variability of water currents and water characteristics, coupled with an inferred preponderance of planktotrophic larvae, are considered as the main factors promoting changes in community structure.
The importance of deposit feeding invertebrates, the types of feeding modes and habitat utilization, and the existence of seasonal patterns, make this community similar to certain temperate zone counterparts. To emphasize these similarities, and for convenience in referring to this assemblage of species, the community is named after a surface deposit-feeding spionid polychaete, a burrowing pinnotherid crab, and a scavenger snail, as the Paraprionospio pinnata - Pinnixa valerii - Nassarius luteostoma community.
References
Bartels, C.E., K.S. Price, Myrna Bussing and W.A. Bussing. 1983. Ecological assessment of finfish as indicators of habitats in the Gulf of Nicoya, Costa Rica. Hydrobiologia 112: 197-207.
Broom, M.J. 1982. Structure and seasonality in a Malaysian mud flat community. Estuar. cstl Shelf Sci. 15: 135-150.
Buchanan, J.B. 1971. Sediments, p. 30-52. In N.A. Holme and A.D. McIntyre (Eds). Methods for the Study of the Marine Benthos. Blackwell Sci. Pub., Oxford.
Cruz, R.A. 1984. Algunos aspectos de la reproducción en Anadara tuberculosa (pelecypoda: Arcidae) de Punta Morales, Puntarenas, Costa Rica. Rev. Biol. Trop. 32: 45-50.
Dauer, D.M. 1985. Functional morphology and feeding behaviour of Paraprionospio pinnata (polychaeta: Spionidae). Mar. Biol. 85: 143-151.
Dean, H.K., D. Maurer, J. A. Vargas & C. H. Tinsman. 1986. Trace metal concentrations in sediment and invertebrates from the Gulf of Nicoya, Costa Rica. Mar. Pollut. Bull. 17: 128-131.
DeVries, M., C.E. Epifando & A.I. Dittel. 1983. Reproductive periodicity of the tropical crab Callinectes arcuatus Ordway in the Gulf of Nicoya, Costa Rica. Estuar. cstl Shelf Sci. 17: 709-716.
Dexter, D.M. 1972. Comparison of the community structues in a Pacific and an Atlantic Panamanian sandy beaches. Bull. Mar. Sci. 22: 449-462.
Dittel, A.I., C.E. Epifanio & J.B. Chavarría. 1985. Population biology of the portunid crab Callinectes arcuatus Ordway in the Gulf of Nicoya, Costa Rica, Central America. Estuar. cstl Shelf Sci. 20: 593-602.
Dixon, W.J. 1974. Biomedical Computer Programs. University of California Press, Berkeley. 450 p.
Epifanio, C.E., D. Maurer & A.I. Dittel. 1983. Seasonal changes in nutrients and dissolved oxygen in the Gulf of Nicoya, a tropical estuary on the Pacific coast of Central America. Hydrobiologia 101: 231-238.
Field, J.G., K.R. Clarke & R.M. Warwick. 1982. A practical strategy for analysing multispecies distribution patterns. Mar. Ecol. Prog. Ser. 8: 37-52.
Goeke, K., Marcella Vitola & G. Rojas. 1981. Oxygen consumption patterns in a mangrove swamp on the Pacific Coast of Costa Rica. Rev. Biol. Trop. 29: 143-154.
Gonor, J.A. & P.F. Kemp. 1978. Procedures for quantitative ecological assessments in intertidal environments. EPA-600/3-78-087. U.S. Environmental Protection Agency, Corvallis. 104 p.
Grant, J., 1983. The relative magnitude of biological and physical sediment reworking in an intertidal community. J. Mar. Res. 41: 673-689.
Gray, J.S. 1974. Animal-sediment relationships. Oceanogr. Mar. Biol. Ann. Rev. 12: 223-261.
Gray, J.S. 1981. The Ecology of Marine Sediments. Cambridge University Press, Cambridge. 185 p.
Green, R.H. & G.L. Vascotto. 1978. A method for the analysis of environmental factors controlling patterns of species composition in aquatic communities. Water Res. 12: 583-590.
Holland, A.F. & T.T. Polgar. 1 976. Seasonal changes in the structure of an intertidal community. Mar. Biol. 37: 341- 348.
Howard, J.D. & J. Dorjes. 1972. Animal-sediment relationships in two beach related tidal flats, Sapelo Island, Georgia. J. Sedim Petrol. 42: 608-623.
Johnson, R.G. 1972. Conceptual models of benthic marine communities. In T.J.M. Schopf (Ed .) Models in Paleo biology. p. 14 8-159. Freeman, Cooper & Co, San Francisco.
Lee, H. 1978. Seasonality, predation and opportunism in high diversity soft-bottom, communities in the Gulf of Panama. Ph. D. Dissertation. University of North, Carolina, Chapel Hill. 210 p.
Maurer, D. & J.A. Vargas. 1984. Diversity of soft-bottom benthos in a tropical estuary: Gulf of Nicoya, Costa Rica. Mar. Biol. 81: 97-106.
Maurer, D., C.E. Epifanio, H. Dean, S. Howe, J. A. Vargas, A.I. Dittel & M.M. Murillo. 1984. Benthic invertebrates of a tropical e stuary: Gulf of Nicoya, Costa Rica. J. nat. Hist. 18: 47-61.
Mills, E.L. 1969. The community concept in marine zoology with comments on continua and stability in some marine communities: a review. J. Fish. Res. Bd. Canada 26: 1415-1428.
Nichols, F.H. & J.K. Thompson. 1986. Persistence of an introduced mud flat community in South San Francisco Bay, California. Mar. Ecol. Prog. Ser. 24: 83-97.
Nie, N.H., C.H. HuIl, J.G. Jenkins, K. Steinbrenner, & D.H. Bent. 1975. Statistical Package for the Social Sciences, 2nd Ed. McGraw Hill, New York. 670 p.
Petersen; C.J. 1914. Valuation of the sea II. The animal communities of the sea bottom and their importance for marine zoogeography. Rep. Danish Biol. Sta. 21: 1-44.
Pimentel, R.A. 1978. Morphometrics. Kendal-Hunt Pub. Co., Iowa. 276 p.
Rathbun, M. 1931. A new Pinnotherid crab from Costa Rica. J. Wash. Acad. Sci. 21: 262-263.
Reise, K. 1985. Tidal Flat Ecology. Springer-Verlag, Berlin. 191 p.
Shin, P.K. 1982. Multiple Discriminant Analysis of macrobenthic infaunal assemblages. J. exp. mar. Biol. Ecol. 59: 38-50.
Sokal, R.R. & F.J. Rohlf. 1969. Biometry. W.H. Freeman & Co., San Francisco. 776 p.
Tabachnick, B.G. & L.S. Fidell. 1983. Using multivariate statistics. Harper & Row Pub., New York. 509 p.
Thistle, D. 1981. Natural physical disturbances and communities of marine softbottoms. Mar. Ecol Prog. Ser. 6: 223-228.
Thorson, G. 1957. Bottom communities (Sublittoral of shallow shelf). Mem. Geol Soc. Am. 67: 461-534.
Vargas, J.A., H.K. Dean, D. Maurer & Pilar Orellana. 1985. Lista preliminar de los invertebrados asociados a los sedimentos del Golfo de Nicoya, Costa Rica. Brenesia 24: 327-342.
Vargas, J.A. 1986. A description of the structure of a tropical intertidal mud flat community. Ph. D. Dissertation. University of Rhode Island, Kingston. 180 p.
VilIalobos, C. 1980. Variation in population structure in the genus Tetraclita (Crustacea: Cirripedia) between temperate and tropical populations. III. T. stalactifera in Costa Rica. Rev. Biol. Trop. 28: 193-291.
Voorhis, A. D., C.E. Epifanio, D. Maurer, AJ. Dittel & J.A. Vargas. 1983. The estuarine character of the Gulf of Nicoya, en embayment on the Pacific Coast of Central America. Hydrobiologia 99: 225-237.
Wade, B. 1972. A description of a highly diverse soft-bottom community in Kingston Harbour, Jamaica. Mar. Biol. 13: 57-69.
Whitlatch, R.B. 1977. Seasonal changes in the community structure of the macrobenthos inhabiting the intertidal sand and mud flats of Barnstable Harbor, Massachusetts. Biol. Bull. 152: 275-294.
Comments
This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright (c) 1987 Revista de Biología Tropical