Population Structure of the Freshwater Crab Trichodactylus Fluviatilis Latreille, 1828 (Decapoda, Trichodactylidae) in Ubatuba, Northern Coast of Sao Paulo State, Brazil

Abstract

The available information on the biology of freshwater crabs, in contrast with marine crabs, remains very scarce making it an important and interesting target for new studies. The objective of the present study was to determine basic parameters of the population structure ofTrichodactylus fluviatilis in Ubatuba, northern coast of the State of Sao Paulo, Brazil. MontWy nocturnal collections were carried out by hand, from March 1998 to February 1999. A total of 306 individuals were captured, 138 males and 168 females. Ovigerous females were not caught during the sampling period, which is probably the result of their cryptic behavior during egg incubation. Female mean size (23.53 ± 4.8 mm CW) was significantly larger than males (22.32 ± 4.8 mm CW)o There was no significant deviation from a I: 1 sex ratio during the studied period and the size distribution of the sampled population presented a normal distribution.

Reproductive behaviour of three species of freshwater crabs of the family Trichodactylidae (Crustacea: Decapoda) including forced copulation by males

“…Maternal care has been described in T. fluviatilis Latreille 1828 (Alarcon et al 2002), Sylviocarcinus australis Milne-Edwards 1853 (Magalhães & Türkay 1996;Mansur & Hebling 2002) and Sylviocarcinus pictus Milne -Edwards 1853(Sant'Anna et al 2013, and in other freshwater crab families such as potamoideos (Gherardi et al 1988;Micheli et al 1990;Cumberlidge 1999;Wehrtmann et al 2010) and Geosesarma notophorum Ng and Tan 1995 (Ng & Tan 1995). Maternal care has also been observed in anomuran crabs of the genus Aegla, including Aegla perobae Hebling and Rodrigues 1977(Rodrigues & Hebling 1978, Aegla violacea Bond Buckup 1994 (Well Bond-Buckup et al 1996) and Aegla uruguayana Schmitt 1942(López Greco et al 2004).…”

“…Besides contributing information about which characteristics determine the continuity of populations, the results of this study could spur advances in applied sciences and predict the state of stocks with conservationist import that is at the centre of all our investigations. Relatively few studies have investigated the behaviour of freshwater tricodactílid crabs (Renzulli & Collins 2001;Alarcon et al 2002;Mansur & Hebling 2002;Williner & Collins 2002;Zimmermann et al 2009;Sant'Anna et al 2014). Mating behaviour, spawning and maternal care during hatching have been described for other families of freshwater crabs Geothelphusa dehaani White 1847 (Minei 1976), Spiralothelphusa hydrodroma Herbest 1794 (Adiyodi 1988), Potamon potamios palestinensis Oliver 1804 (Gherardi & Micheli 1989), Potamon fluviatile Herbest 1785 (Micheli et al 1990) and for other crustaceans (Andrews 1916;Mason 1970;Ingle & Thomas 1974;Barki & Karplus 1999;López Greco et al 2004;Almerão et al 2010).…”

Littoral Communities. Macrocrustaceans

“…The post-hatching spatial and trophic competition decreases in the first reproductive event of these sympatric species (Collins 2000). The intimate mother-juvenile relationship at the first stages in trichodactylids (Alarcón et al 2002;Mansur and Hebling 2002) and aeglids includes parental care, which decreases the risks in juveniles. After the asynchronous hatching, juveniles of A. uruguayana remain between 3 and 4 days with the female (López Greco et al 2004).…”

“…This is reflected in different mortality rates for males and females, recruitment pulses and differential movements, according to sex and habitat preferences for each sex (Díaz and Conde 1989). In other tropical and subtropical crabs, simple modes in the size distribution are observed, reflecting differences with populations of temperate regions (Alarcón et al 2002).…”

Juvenile Hatching and Maternal Care in Aegla Uruguayana (Anomura, Aeglidae)

“…violacea (see Rodrigues and Hebling, 1978;BondBuckup et al, 1996;Bueno and Bond-Buckup, 1996), and in freshwater crayfishes species, such as Austropotamobius pallipes (see Reynolds et al, 1992), Cherax quadricarinatus von Martens, 1868 (see Levi et al, 1999), Cambaroides japonicus de Haan, 1842 (see Kawai and Scholtz, 2002), and in the South American Parastacidae, Parastacus pugnax, P. nicoleti, and Samastacus spinifrons (see Rudolph and Ríos, 1987;Rudolph and Iracabal, 1994). Within the Brachyura, maternal care is found in freshwater crabs with direct development, as in the Trichodactylidae species Trichodactylus fluviatilis Latreille, 1828, Dilocarcinus pagei Stimpson, 1861, and Sylviocarcinus australis Magalhães and Tukay, 1996 (see Alarcón et al, 2002;Mansur and Hebling, 2002), in Potamoidea (Gherardi et al, 1988;Micheli et al, 1990;Cumberlidge, 1999), in Geosesarma notophorum Ng andTan, 1995 (see Ng andTan, 1995), and in various species of Grapsoidea with abbreviated development (Diesel, 1989;Diesel 1992;Diesel et al, 2000).…”