Biology of the Antarctic eelpout Pachycara brachycephalum

The aim of this study was to relate the distribution of the Antarctic eelpout, Pachycara brachycephalum, to available physiological data, and to detect constraints in life history and biology. A population of Pachycara brachycephalum from the Antarctic Peninsula was investigated with regard to its growth and fecundity. At this sampling site, the species occurs in water depths around 400 m, much shallower than where it is found in high Antarctic waters. The age of this species was determined by applying the annulus count method to the otoliths. Growth parameters, which show no strong sexual dimorphism, are L∞=36.0cm; k=0.12k=0.12; t0=-1.75t0=-1.75 (male) and L∞=36.0cm; k=0.10k=0.10; t0=-2.99t0=-2.99 (female). The maximum age found was 14 years, and maturity is reached after 5 years. At the end of July, females spawn about 80 eggs with a diameter of 9 mm. The smallest fish found so far was an early juvenile of 4.4 cm. The life style characteristics of this species are similar to other polar and boreal eelpout species, supporting the uniformity of the Zoarcidae in general traits.