CCAMLR

A revision of the calculation of total international catch at age of Champsocephalus gunnari over the period 1976/77 to 1990/91 is presented. This uses iterative application of two age length keys to obtain age distributions, according to a method described by Kimura and Chikuni (1987). It is proposed that the revised catch at age be used for future assessment of the C. gunnari fishery at South Georgia using VPA.

Ovarian maturation in Notothenia coriiceps is known to include a period during which yolk deposition begins to take place. This 'adolescent' phase was thought originally to last for about one year. The results from a two year study at Signy Island indicate that this adolescent phase lasts for about four years. There is also some evidence to indicate that not all sexually mature fish spawn each season. Two reproductive strategies are considered, one where adverse conditions are accompanied by a failure to spawn and an alternative where fecundity is controlled by the number of small oocytes which ripen.

The Lepidonotothen squamifrons group has been described to be comprised of 3 species: L squamifrons (Günther, 1880). L kempi (Norman, 1937) and L macrophthalma (Norman, 1937). All 3 species closely resemble each other and morphological and meristic characters utilized to distinguish between species are overlapping. Enzyme electrophoresis of enzyme polymorph isms has been applied to specimens morphologically recognized as L squamifrons and L kempi from various localities in the Scotia Arc region and the Kerguelen Islands to assist in clarifying their taxonomic status. Results suggest that both 'species' represent only populations of one species. Evidence is presented that the third species of the group, L macrophthalma, may also be identical with L squamifrons and that the L squamifrons 'group' is comprised of only one species, Lepidonotothen squamifrons (Günther, 1880). We found no statistically significant difference in allele frequencies between specimens from geographically isolated shelf areas of the Scotia Arc. This does not necessarily mean that the Scotia Arc region is inhabited by a single population but suggests some gene flow between shelf areas via larval drift for which evidence exists.