Size at morphological sexual maturity of the spider crab libinia spinosa (brachyura) in Patagonian gulas

GONZÁLEZ PISANI X. ; BARÓN P.; LOPÉZ GRECO LAURA

BIOCELL

Biocell

Lugar: Buenos Airres; Año: 2009 vol. 32 p. 209 - 209

0327 9545

In the Brachyuran crabs, the size of the chelipeds is relevant for male mating success and the width of the pleon to maximize the egg carring capacity of the females during incubation. The detection of discontinuities in some morphometric relationships associated to these structures allows to establish the size of morphologic maturity, generally related to the puberty molt. With the aim of determining the size of morphological maturity in Libinia spinosa, 385 individuals (206 females and 179 males) of different sizes were captured in the northern Patagonian gulfs (41-43ºS) by trapping and SCUBA diving at depths between 5 and 40 m. Width of carapace (CW) and different dimensions of the chelipeds and pleon were measured. In females, discontinuities were detected in the relationship pleon width (PW) and the CW, both morphologically immature and mature individuals being present in the range of 41.3-50.9 mm CW. The smallest ovigerous female had a CW of 41.3mm. For males, a breakpoint was detected in the relationship of cheliped length (CL) and CW at 37 mm CW (size rangel of 32-43mm) AC. The size at morphologic maturity of females was similar to that found in Leurocyclus tuberculosus (40.33 mm CW), another Majoidea associated to the captures of L. spinosa, and the size obtained for the males was lower than the size registered for that species (55 mm CW).