Comparison of body size, relative growth and size at onset sexual maturity ofUca uruguayensis(Crustacea: Decapoda: Ocypodidae) from different latitudes in the south-western Atlantic

Abstract

Some crustaceans show variations of their reproductive biology within their geographical distribution, and knowledge about such variations is important for the comprehension of their reproductive adaptations. This study compared two populations of the fiddler crab Uca uruguayensis from two locations on the south-western Atlantic coast: Ubatuba Bay, São Paulo, Brazil and Samborombón Bay, Buenos Aires, Argentina. The population features analysed were the body size variation (carapace width ¼ CW) and the size at the onset of sexual maturity (SOM) in order to test the hypothesis that the size at SOM, should be the same in relative terms (RSOM), independently of the latitudinal position. In the Brazilian population the CW ranged from 4.18 to 11.60 mm for males and 3.90 to 9.80 mm for females, and in the Argentinean population from 3.60 to 14.10 mm for males and 2.85 to 12.00 mm for females. In the Brazilian population the SOM was 7.1 (RSOM ¼ 0.58) and 5.9 mm CW (RSOM ¼ 0.57) for males and females, respectively, and in the Argentinean population it was 7.0 (RSOM ¼ 0.42) and 6.75 mm CW (RSOM ¼ 0.53) for males and females, respectively. This fact is probably related to a great plasticity in the life history features of Uca uruguayensis under different environmental conditions.

Comparative biology of the crab Goniopsis cruentata: geographic variation of body size, sexual maturity, and allometric growth

“…Accordingly, crabs can avoid exposure to extremely hot and dry conditions through reduced active behavior to prevent water loss. This could potentially restrict feeding times, resulting in reduced food intake in Ceará and a reduced growth rate (Hirose et al 2013). However, our results contradict the general trend of larger body sizes toward high latitudes that has been reported found for many crustaceans (e.g., Jones and Simons 1983;Wehrtmann et al 2012;Hirose et al 2013).…”

“…We might expect that if body size and maturity vary between populations under different environmental conditions, the allometric growth of reproductive structures will as well. However, to our knowledge, studies that have attempted to test such variation are rare (but see Hirose et al 2013).…”

Relative growth in the fiddler crab Uca uruguayensis Nobili, 1901 (Brachyura, Ocypodidae) from Garças River mangrove, Guaratuba Bay, southern Brazil

“…While the male´s maximum CW of the populations from Ubatuba, SP (Brazil) and from Samborobón (Argentina) measured 11.60 mm and 14.10 mm, respectively (Hirose et al, 2013), that of Guaratuba Bay was 8.33 mm. This difference is still more striking when compared with the population from Maldonado, Uruguay (= 16.0 mm CW), which is almost twice the size determined for Guaratuba`s males (Nobili, 1901).…”

“…A total of ten species of Uca are known from Brazil, among which, seven had their relative growth studied: Uca rapax Smith, 1870 from Rio de Janeiro State (Castiglioni et al, 2006;Costa and Soares-Gomes, 2008) and from São Paulo State (Castiglioni and Negreiros-Fransozo, 2004); Uca thayeri Rathbun, 1900(Negreiros-Fransozo et al, 2003; Uca burgersi Holthuis, 1967 (Benetti and; Uca leptodactyla Rathbun, 1898 from São Paulo State (Cardoso and Negreiros-Fransozo, 2004) and from Santa Catarina State (Masunari and Swiech-Ayoub, 2003); Uca mordax Smith, 1870 ; Uca maracoani Latreille, 1802-1803 from Paraná State; and Uca uruguayensis Nobili, 1901 from São Paulo State and from Samborombón, Argentina (Hirose et al, 2013).…”

Temporal distribution in the abundance of the fiddler crab Uca (Leptuca) uruguayensis Nobili, 1901 (Decapoda: Ocypodidae) from Garças River mangrove, Guaratuba Bay, southern Brazil

“…The population of the Guaratuba Bay is composed of the smallest individuals (males 2.33 to 8.33 mm, non-ovigerous females 2.52 to 7.79 mm and ovigerous females 5.05 to 6.95 mm). The population from Itacuruçá mangrove, Rio de Janeiro, measured 4.57 to 12.00 mm (males) and 5.00 to 10.86 mm (females) (Bedê et al, 2008), from Indaiá River mangrove, São Paulo, measured from 4.18 to 11.60 mm (males) and 3.90 to 9.80 mm (females) (Hirose et al, 2012), and from Argentina, maximum CW values measured were 14.47 mm (males) and 13.43 mm (females) (Spivak et al, 1991) and 14.10 mm (males) and 12.00 mm (females) (Hirose et al, 2012). Differences in food availability seem to be the main cause for this strong CW discrepancy among populations from different localities (Colpo and NegreirosFransozo, 2004).…”