A brief outline of the biology of the Antarctic silverfish, Pleuragramma antarcticum Boulenger, 1902 (Nototheniidae) from the Antarctic Indian Ocean

The Antarctic silver fish (Pleuragramma antarcticum) is one of the most numerous species in the outer waters of Antarctica. In the Indian sector of the Southern Ocean there are at least three relatively isolated groups. Fish aged from 0+ to 3+ years live in the epi- mesopelagic zone where there are macro aggregations of plankton, while fish aged from 3+ to 12+ years form near-bottom, pelagic schools. Fish belonging to various spatial groups have different growth characteristics, Females mature when they reach 13-16 cm in length and 4-6 years of age. Males reach maturity at 12-18 cm in length and 4-7 years of age. The potential absolute and relative fertility of this species is one of the highest for high-latitude Antarctic fish. Spawning occurs in the winter-spring period. P. antarcticum is a plankton-eater and is itself an important part of the diet of species higher up the food-chain. P. antarcticum has a fairly high level of instantaneous natural mortality, mainly due to its position on the food chain. It would probably be unwise to commence exploratory commercial fishing of this species in areas of international monitoring.