Efecto de períodos de ayuno en el crecimiento de la zoea I de Petrolisthes violaceus (Guérin, 1831) (Decapoda: Anomura: Porcellanidae)

Abstract

The present study describes consequences of starvation upon growth (wet and dry weight) and survival of zoea I - larvae of Petrolisthes violaceus, a common species of the Chilean intertidal belt. The experimental design included five groups (1-5 days after hatching without food, respectively) as well as one starvation treatment and one control (larvae were fed daily). Food (Artemia franciscana) consisted in 15 nauplii per ml. Temperature was kept at 19°C and salinity at 34/oo.The larvae which were fed daily achieved the highest biomass increase, gaining 94.7% of its initial dry weight. In other experiments (2-5 days of initial feeding) a slight biomass increase was observed. Larvae fed only one day and those under starvation conditions lost biomass: starved larvae a continuos biomass decrease up to 18.9% of its initial dry weight. The Point of Reserve Saturation was at 4 days. The first zoeal stage of P. violaceus demostrated a low starvation resistance, since zoea I was not capable to complete the molt cycle in the absence or with brief periods (1-3 days) of food. Furthermore, larvae molted only when they inceased their initial body weight by more then half (55.4%). Our results suggest that larvae of P. violaceus possess a high capacity of assimilation since they start loosing biomass not before two days of starvation.This capacity may permit to compensate the biomass loss caused by food deprivation.