Rev. biol. mar. oceanogr. 49(1): 81-90

Article

Relative growth and reproductive parameters in a population of Microphrys bicornutus (Brachyura, Majoidea) from Bocas del Toro, Caribbean Sea, Panama

María Paz Sal-Moyano¹, Ana Milena Lagos-Tobias², Darryl L. Felder³ and Fernando L. Mantelatto⁴

¹Instituto de Investigaciones Marinas y Costeras (IIMyC), Laboratorio de Humedales y Ambientes Costeros, Estación Costera J.J. Nágera, Departamento de Biología, Universidad Nacional de Mar del Plata, Funes 3350, 7600, Mar del Plata, Argentina

²Programa de Biología, Universidad del Magdalena, Carrera 32#22-08, Santa Marta, Colombia

³Department of Biology, Laboratory for Crustacean ResearchThis email address is being protected from spambots. You need JavaScript enabled to view it., University of Louisiana -Lafayette, Lafayette, LA 70504-2451, United States

⁴Laboratory of Bioecology and Crustacean Systematics, Department of Biology, Faculty of Philosophy, Sciences and Letters at Ribeirão Preto (FFCLRP), University of São Paulo (USP), Postgraduate Program on Comparative Biology, Av. Bandeirantes 3900, 14040-901, Ribeirão Preto, São Paulo, Brazil

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Size structure within a population, relative growth of secondary sexual characters in both sexes, and fecundity of females were assessed from field samples of Microphrys bicornutus in the vicinity of Bocas del Toro, Caribbean Sea, Panama. The study was based upon 135 individuals captured by hand and a kick net. Carapace width ranged from 6.5 to 14.4 mm for ovigerous females, 4.2 to 16 mm for non-ovigerous females, and 5.9 to 17.4 mm for males. The relative growth of carapace length versus carapace width was isometric in males and negatively allometric in females. Relative growth of the chela length and abdomen width, compared to the carapace width, exhibited 2 phases, immature and mature, for males and females, respectively. The carapace widths at which 50% of males and females reached morphometric maturity were 13.6 and 8.5 mm, respectively. The mean value of the reproductive output was 3.6, the relative fecundity was 2041.91 eggs, and the relative size at the onset of sexual maturity was 0.4. As in most brachyuran species, the studied population of M. bicornutus showed a strong positive correlation between fecundity and body size. Differences in those parameters for previously studied populations from Venezuela, Jamaica and Brazil may be due to latitudinal or regional environmental effects.

Key words:  Caribbean Sea, fecundity, relative growth, sexual maturity, spider crab