Aspects of the biology of galjoen Coracinus capensis (Cuvier) off the South-Western Cape, South Africa

Abstract

Various aspects of the biology of galjoen, an important shore-angling fish along much of the southern African coast, are described from samples collected between February 1984 and July 1985. Galjoen live in shallow, often very turbulent, waters where they feed mainly on sessile invertebrates such as bivalve molluscs and barnacles, and on amphipods and algae. The average size of fish sampled was 359 ± 59 mm total length, females, at 380 ± 62 mm, being significantly larger than males, at 349 ± 39 mm. Females grow faster than males, attaining some 550 mm or 3,3 kg at 12 years of age, whereas males of the same age reach only 440 mm or 1,5 kg. Fish of both sexes attain sexual maturity in their sixth year, at which stage females measure 340 mm and males 310 mm. Galjoen are serial spawners with a breeding season that extends from October to March, peaking in December. Mature females produce approximately 370 eggs per gramme of body mass at each spawning. The above data are used to assess the current conservation status of galjoen. The existing legislative package is seen as appropriate to management of this sought-after species. © 1986 Taylor & Francis Group, LLC.