Examination of female energy dynamics and larval quality in the southern king crab, Lithodes santolla: Annual and interannual variability

Abstract

The southern king crab, Lithodes santolla, constitutes one of the most important fishery resources in the Beagle Channel. In this study, we considered that Lithodes santolla females showing better physiological conditions may produce larvae with higher survival rates. To determine whether this quality may be useful for the enhancement of natural crab stocks, in the present study, we aimed to evaluate several biochemical parameters considering the size and ovigerous condition of the female parent. Primiparous (<80 mm CL) and multiparous (>80 mm CL) females, as well as ovigerous and non-ovigerous females, were evaluated. The patterns of accumulation or use of several macromolecules (glycogen, lipids and proteins) in different organs and development stages (midgut gland, ovary, eggs, larval stages and first crabs) were also evaluated along two reproductive seasons. The possibility that some females could be producing larvae with high survival was evaluated through the relationship between the female midgut gland and ovarian quality and the larvae. The results obtained indicate that the energy content of L. santolla females is highly variable according to the year, season, and month, and between primiparous and multiparous females. We hypothesized that this variability in the energetic quality is explained by differences in the female's diet: food availability or food quality during ovary maturation. Most of the energy reserves of the ovary are transferred to the offspring. The only female parent-brood connection is through the energy reserves transferred to the eggs 10 months earlier, and we hypothesize that this depends on the previous environmental and female feeding conditions during ovarian development. Moreover, zoea I larvae showed high variability in survival, not influenced by their own energy reserves or by the reserves of the eggs or the ovary. The physiological variables here analyzed did not allow identifying better females that can produce larvae with higher survival.