Age, growth and reproductive biology of diamond-shaped squid Thysanoteuthis rhombus (Oegopsida: Thysanoteuthidae)

Abstract

T. rhombus captured in the E tropical Atlantic and SW Pacific between 1976 and 1990 were examined. The maximum ages found were observed in a mature female of 750 mm ML (305 d) and in a mature male of 770 mm mantle length (ML) (309 d). The life span of T. rhombus was estimated to be about one yr. T. rhombus is one of the fastest-growing squids: by age 300 d. they reached 750 to 800 mm ML and 17-17.5 kg body weight (BW). The increase in both ML and BW during ontogenesis was best fitted by a logistic growth curve. It is suggested that T. rhombus is an intermittent spawner with multiple filling and excavation of oviducts. -from Authors