Survival and condition of southern king crab Lithodes santolla larvae in cultivation:

TAPELLA, FEDERICO; SOTELANO, M. PAULA; ROMERO, MARÍA CAROLINA; LOVRICH, GUSTAVO ALEJANDRO

Shanghai Ocean University, China

Congreso; International Symposium on Aquaculture, Biology and Management of Commercially Important crabs-2009; 2009

Shanghai Ocean University and Chinese Crustacean Society

The Southern King Crab (SKC) constitutes the most important crab fishery in Southern South America. Landings peaked during the 70’s and afterwards declined until 90’s, when the Beagle Channel 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, an alternative to enhance the SKC population may be the massive production of juveniles to subsidize the natural population. This study is a part of a research program for improving the knowledge of SKC larval cultivation and early life history. Since larval hatching of a single batch occurs during 4-5 weeks, our aim was to determine the larval survival (LS) to crab 1 stage (C1) at different hatching periods (early, middle and late), and its relationship with female size. Ovigerous females were caught at the Beagle Channel (54ºS, 68ºW) and maintained individually in a recirculation seawater system during the whole hatching period., At early, middle and late of the hatching period (5-7, 15-17 and 25-27 days from hatching beginning, respectively), energetic condition of recently hatched larvae was assessed and larvae were cultured at 15 ind•L-1. All cultures were performed at 8ºC and without food since larvae are endotrophic. Water was changed thrice a week and previously filtered to 20µm and UV-sterilized. Daily, dead larvae and molts were removed, and survival and development time (DT) to C1 was calculated. LS was different among periods (ANOVA, p=0.01, n=6). Larvae from the middle period showed a higher survival (87.5±9.3%; Tukey, p<0.05) than those hatched at the beginning or end of the hatching period (49.2±32.8 y 40.8±26.3%, respectively). DT to C1 and energetic content of larvae were similar (ANOVA, p=0.22, n=6; p=0.57, n=7, respectively) among hatching periods (~59.9±1.2 days and 24.19±0.43 kJ•g-1). Finally, although linear regression between LS and female size was marginally not significant (p=0.07, n=14), our data indicate that LS increase with female size. Information here provided is useful to optimize survival of SKC larvae in hatcheries to produce large numbers of C1 for both laboratory experiments and stock enhancement program.