Aspects of the gonadal cycle in the antarctic bivalve Laternula elliptica

Abstract

Vitellogenesis and oocyte growth in Laternula elliptica, a common hermaphrodite bivalve living in the softmuddy bottoms of the Antarctic continent, are reported. Formation of the gelatinous layer surrounding the oocyte, gonadic development,accumulation of mature oocytes, and spawning events were studied through histological evidence. Gonads were observed toreach maturity at a size of 49 mm. Vitellogenesis has been found to last seven months, and storage of oocytes before spawningwas observed. It has been observed that once sexually mature, the animals remain with sperm cells and oocytes available duringthe entire year, suggesting that individuals would be prepared to spawn at any moment, probably depending on environmentalconditions.