Population structure, recruitment, and mortality of the freshwater crab Dilocarcinus pagei stimpson, 1861 (Brachyura, trichodactylidae) in Southeastern Brazil

Freshwater crabs of the family Trichodactylidae are widely distributed in major river basins of the South American continent. The population structure of one species, Dilocarcinus pagei, was analyzed in an artificial reservoir in Southeastern Brazil, recording data on the sex ratio, recruitment, and...

Full description

Bibliographic Details
Authors: Taddei, Fabiano Gazzi, Davanso, Thiago Maia [UNESP], Castiglioni, Lilian, Herrera, Daphine Ramiro [UNESP], Fransozo, Adilson [UNESP], Da Costa, Rogério Caetano [UNESP]
Format: article
Status:Published version
Publication Date:2015
Country:Brasil
Institution:Universidade Estadual Paulista (UNESP)
Repository:Repositório Institucional da UNESP
Language:English
OAI Identifier:oai:repositorio.unesp.br:11449/172070
Online Access:http://dx.doi.org/10.1080/07924259.2015.1081638
http://hdl.handle.net/11449/172070
Access Level:Open access
Keyword:Crustacea
Ecology
Juvenile recruitment
Reproduction
Description
Summary:Freshwater crabs of the family Trichodactylidae are widely distributed in major river basins of the South American continent. The population structure of one species, Dilocarcinus pagei, was analyzed in an artificial reservoir in Southeastern Brazil, recording data on the sex ratio, recruitment, and mortality. A total of 1339 crabs were collected and included 804 males and 535 females (3 ovigerous and 4 with hatchlings); the sex ratio was 1:0.61 (males: females). Two modes of male and female carapace width (CW) were recorded, with means of 14.4 mm (n = 407) and 38.9 mm (n = 394) for males and 17.9 mm CW (n = 269) and 39.2 mm (n = 267) for females. The mean size of males (CW = 26.6 ± 13.8 mm) was significantly larger than that of females (CW = 28.5 ± 12.8 mm). The data indicated that recruitment occurs in summer (January-March), with the reproductive period in spring (October-December), periods with the highest rainfall and temperature values in the region. Reproduction leads to the death of the parents, influencing the sex ratio, which oscillates mainly during the reproductive period.