Energy storage and utilization in relation to gametogenesis in Argopecten irradians concentricus (say)

Abstract

A seasonal cycle of growth and energy storage prior to gonad development followed by utilization of pre-stored reserves for gametogenesis was observed in Argopecten irradians concentricus (Say) collected from the Anclote Estuary near Tarpon Springs, Florida. Somatic growth occurred in spring as adductor muscle, mantle, and digestive gland body components increased in dry weight and protein content. Reserve energy was stored in the digestive gland as lipid and in the adductor muscle, the primary energy storage site, as glycogen and protein. Gametogenesis in summer was associated with an increase in gonad dry weight and lipid and protein contents and took place at the expense of the previously stored energy reserves. Digestive gland lipid utilization was associated with initiation of the oocyte growth phase. Decrease in adductor muscle glycogen content was significantly correlated with increase in oocyte diameter during cytoplasmic growth and vitellogenesis. Adductor muscle protein was utilized to meet maintenance demands during the later gametogenic stages and spawning. After spawning in autumn, energy reserves were depleted, possibly contributing to the high mortality characteristic of post-spawn scallops of this subspecies.