Effect of starvation and refeeding on the ultrastructure of the perigastric organ (hepatopancreas) in the whiteleg shrimp Litopenaeus vannamei (Boone, 1931) (Decapoda: Caridea: Penaeidae)

摘要

Farmed caridean shrimps can experience starvation periods attributable to disease outbreaks or adverse environmental conditions. The hepatopancreas, or perigastric organ, of decapods, being the principal organ for storage of nutrients that can be mobilized during non-feeding periods, plays a fundamental role during starvation. We studied the ultrastructural changes in the perigastric organ of whiteleg shrimp Litopenaeus vannamei (Boone, 1931), a commonly farmed species, during starvation and refeeding. Starvation induced a progressive increase of cellular immunity (haemocytic infiltration, both hyaline and granular and/or semigranular haemocytes), necrosis (swelling of organelles and cytolysis), and autophagy (formation of phagophores, autophagosomes, autolysosomes, and multivesicular and residual bodies). The complete depletion of lipid droplets and a few signs of apoptosis (chromatin condensation and nuclear fragmentation) were also observed during starvation. Refeeding resulted in a partial recovery of the perigastric organ. Findings demonstrate the capacity of the perigastric organ to recover when refed for ten days after five days of starvation. Longer starvation periods severely affect the perigastric organ, causing potential economic losses to famers.