Abstract
The present study shows spatial patterns in the faunal assemblage of decaying wood and sediments, with emphasis on the polychaetes. The survey was executed across a salinity gradient in a tropical mangrove estuary of Costa Rica. To capture the organisms we analyzed decomposing logs found in the Térraba mangrove and sediment samples were taken with a corer in the sand bottom. Seven different phyla were found in the sediment samples. Of the 192 individuals found in the sediment samples, 18 were polychaetes belonging to nine families and 11 species. Analyses of decaying wood resulted in 2 564 individuals distributed in five phyla. Polychaetes accounted for 429 individuals belonging to eight families and 16 species. Although, polychaetes were more abundant in decaying wood, and their diversity was lower. The abundance of polychaetes in decaying wood was negatively correlated with the number of individuals of Mollusca, Hexapoda and Crustacea. A change in the composition of polychaetes in decaying wood was found along the salinity gradient of this estuarine zone. Dissimilarities in the composition of benthic fauna in decaying wood and sediments in the Térraba mangrove showed that biodiversity was increased by the microhabitats inside the mangrove forest. Finally, several genera or species of polychaetes are new records for Costa Rica and the Central American Pacific Coast.
Highlights
Mangroves are transition ecosystems between marine and terrestrial habitats
The first goal was the collecting of decapod species (Echeverría-Sáenz et al, 2003), in the present study we identified other faunal groups found in these samples
Polychaetes were found in only four of the 10 sediment samples and accounted for 18 individuals belonging to nine families and 11 species
Summary
Mangroves are transition ecosystems between marine and terrestrial habitats. They are representative of tropical and subtropical regions where they reach their greatest development (Lacerda et al, 1993; Jiménez, 1994; Mainardi, 1996; Oshiro, Silva, & Silva, 1998). As mangroves are a combination of marine, terrestrial and freshwater habitats a great variety of fauna can be found (Jiménez, 1994), and their existence depends on the tides, time of the year, life cycle, (Wehrtmann & Dittel, 1990; Dittel, Epifanio, & Lizano, 1991; Lacerda et al, 1993; 2001; Macintosh, 1988) In spite of this known high biodiversity, there are few studies that include detailed quantification and identification of organisms (Skov, Vannini, Shunula, Hertnoll, & Cannicci, 2002). The relationship of this fauna of decaying wood with the salinity gradient in a tropical mangrove of Costa Rica is analyzed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
