Survival and condition of southern king crab Lithodes santolla larvae in cultivation: tools for stock enhancement.

TAPELLA, F; SOTELANO, M.PAULA; ROMERO, MC; LOVRICH, GA

Shanghai

Simposio; International Symposium on Aquaculture, Biology and Management of Commercially Important Crabs; 2009

Shanghai Ocean University

The Southern King Crab (SKC) constitutes the most important crab fishery in Southern SouthAmerica. Landings peaked during the 70’s and afterwards declined until 90’s, when the BeagleChannel was declared overfished. This promoted areas with different fishing efforts. However,in spite of this restriction 14 years after the fishery closing, stock partially recovered . Thus, analternative to enhance the SKC population may be the massive production of juveniles tosubsidize the natural population. This study is a part of a research program for improving theknowledge of SKC larval cultivation and early life history. Since larval hatching of a single batchoccurs during 4-5 weeks, our aim was to determine the larval survival (LS) to crab 1 stage (C1) atdifferent hatching periods (early, middle and late), and its relationship with female size.Ovigerous females were caught at the Beagle Channel (54ºS, 68ºW) and maintained individuallyin a recirculation seawater system during the whole hatching period., At early, middle and late ofthe hatching period (5-7, 15-17 and 25-27 days from hatching beginning, respectively), energeticcondition of recently hatched larvae was assessed and larvae were cultured at 15 ind•L-1. Allcultures were performed at 8ºC and without food since larvae are endotrophic. Water waschanged thrice a week and previously filtered to 20µm and UV-sterilized. Daily, dead larvae andmolts were removed, and survival and development time (DT) to C1 was calculated. LS wasdifferent among periods (ANOVA, p=0.01, n=6). Larvae from the middle period showed a highersurvival (87.5±9.3%; Tukey, p<0.05) than those hatched at the beginning or end of the hatchingperiod (49.2±32.8 y 40.8±26.3%, respectively),. DT to C1 and energetic content of larvae weresimilar (ANOVA, p=0.22, n=6; p=0.57, n=7, respectively) among hatching periods (~59.9±1.2days and 24.19±0.43 kJ•g-1). Finally, although linear regression between LS and female size wasmarginally not significant (p=0.07, n=14), our data indicate that LS increase with female size.