Relationship between energy allocation and gametogenesis in Aulacomya atra (Bivalvia: Mytilidae) in a sub-Antarctic environment

PÉREZ, A.F.; BOY, C.C.; CURELOVICH, J.; PÉREZ BARROS, P.; CALCAGNO, J.A.

REVISTA DE BIOLOGIA MARINA Y OCEANOGRAFIA

INST OCEANOLOGIA

Lugar: Valparaíso; Año: 2013 vol. 48 p. 459 - 469

0717-3326

The gametogenesis and temporal variation in energy allocation to different organs of Aulacomya atra, from the Beagle Channel (Tierra del Fuego) were analyzed. Our results show that A. atra presents an extended spawning period from late winter to spring when the lowest value of MGI (mantle-gonad index) and the maximum number of spawned individuals were observed. The increasing MGI in maturing males occurs with a decreasing energy density of the mantle-gonad (EDMG), indicating an increment of mass of lower energy values in males. The increasing MGI in maturing females is accomplished with an increase in mass of higher energy values, increasing EDMG. Consequently, similar energy content of mantle-gonad (ECMG) is reached by means of different strategies in both sexes; males maintain gonads of bigger size but with lower energy by unit of mass than females. Besides, we observed a drop in the digestive gland index (DGI) in concordance with an increase in the MGI of mature individuals, and a trend towards the depletion of ED and EC in the digestive gland during gonadal maturation. Our results evidence the role of the digestive gland as an energy reservoir and a different energy allocation strategy between sexes during gonadal maturation.