Ontogenetic changes in energetic reserves, digestive enzymes, amino acid and energy content of Lithodes santolla (Anomura: Lithodidae): Baseline for culture

Abstract

The southern king crab (SKC) Lithodes santolla is an important commercial species in southern South America. Fishing pressure has caused the deterioration of its stocks. Currently, culture techniques are being developed for producing SKC juveniles to enhance the natural population and to recover the fishing stock. Therefore, it is necessary to know about physiology, energetic and nutritional requirements for SKC maintenance in hatchery. Thus, this study aims to evaluate the biochemical and physiological changes in the midgut gland, muscle and hemolymph of juveniles, pre-adults and adults of wild SKC. The energetic reserves, digestive enzymes activity, amino acid profile and energy were quantified in twelve juveniles, ten pre-adult, and ten adult crabs. Juveniles showed high glycogen and low lipids in the midgut gland, and low proteins and low lactate in muscle. In the hemolymph, juveniles had high lipids. Pre-adults had high glycogen and lipids in the midgut gland, and both high protein and lactate in muscle. In the hemolymph, pre-adults had high lipids. Adults had low glycogen and high lipids in midgut gland, and both high proteins and high lactate in muscle. In hemolymph, adults had high glucose and lactate. Juveniles and pre-adults had high proteinase activity, whereas adults had high lipase activity. Major essential amino acids of SKC were arginine, methionine, and tryptophan, and the non-essential amino acids were glycine, aspartic acid and glutamic acid. On another hand, SKC had similar energy in the midgut gland and muscle, regardless of the ontogenetic stage. Moreover, we demonstrated that the biochemical energy calculation underestimates the actual measured values by a calorimeter. Thus, our results help to understand the physiological changes, energetic and nutritional requirements of L. santolla, and this study is a baseline for research on diet formulation for maintaining this species under culture conditions.

Evaluation of Morphological and Quality Parameters in Adult Male Red King Crabs (Paralithodes camtschaticus) Raised to Commercial Weight from Juveniles

“…Another element that could contribute to suboptimum LH conditions is the natural shift in the conditions for wild RKCs from juvenile to adult. During the ontogenetic stages, from juvenile RKCs, their natural habitat and, thus, food source may change, and that size gain and habitat shift often occur concomitantly [26,30]. In our study, the same habitat and feed (shrimp, herring, sea urchins, and capelin) were used through the entire LH period of 23 months.…”

Effects of Dietary L-TRP on Immunity, Antioxidant Capacity and Intestinal Microbiota of the Chinese Mitten Crab (Eriocheir Sinensis) in Pond Culture

“…A study has shown that the effect of TRP in diets likely depends on the species and developmental stages [ 58 ]. In addition, juvenile crabs have higher amino acid requirements than pre-adults and adult crabs [ 59 ]. Therefore, our results suggest that the proper addition of L-TRP, according to the body size of the animals, may reduce oxidative damage.…”