Embryonic development and fecundity of the squat lobster Munida gregaria (Decapoda, Galatheidae) in Northern Patagonia

DELLATORRE F.; GONZÁLEZ PISANI X.

JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM

CAMBRIDGE UNIV PRESS

Año: 2011 vol. 91 p. 695 - 704

0025-3154

In this study, fecundity of Munida gregaria in northern Patagonia was analysed in relation to size and compared with otherstudies in different sites along its latitudinal distribution. Also, morphological changes in embryos reared in the laboratory,and the chronology of its appearance were observed. Fecundity (total number of eggs in a clutch) was strongly correlated tosize (carapace length in mm) (R ¼ 0.638) and the regression equation fitted by least squares was Log(F) ¼ 21.37 + 3.85 .log(CL). Size specific fecundity was higher than in southern locations along Patagonia. Recently extruded eggs are smallerthan in southern Patagonia measuring an average of 530 mm in diameter and 0.043 mm3 in volume. When ready tohatch, those measures increased by 30% and 50% respectively. Complete embryonic development lasted an average of 27.9days at fixed temperature of 118C. Five development stages were defined based on morphological changes: (1) from fertilizationto the appearance of embryonic primordium (2?3.5 days); (2) embryonic tissues occupying less than half of the egg perimeterin lateral view (7?10 days); (3) embryonic tissues without pigments and occupying more than half of the egg perimeterin lateral view (5?8 days); (4) embryos with reddish eye pigments and chromatophores (4?6 days); and (5) ocular globecompletely pigmented (3?4 days).