Timescale of ovarian maturation in Notothenia coriiceps (Richardson); evidence for a prolonged adolescent phase

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.