ON THE LIFE-HISTORY OF THE LESSER GURNARD (SCORPAENIFORMES, TRIGLIDAE) INHABITING THE AGULHAS BANK, SOUTH-AFRICA

Growth analysis based on sectioned sagittal otoliths revealed the less er gurnard Chelidonichthys queketti on the Agulhas Bank to be relative ly fast growing and long lived, with ages of up to 7 years being recor ded. Total length at age (mm) was described best by the specialized vo n Bertalanffy growth model as L-T=306.1 (1 -e(0-53(t+0.18))). First ap proximations of total, natural and fishing mortality rates were determ ined at 0.73, 0.38 and 0.35 year(-1) respectively. The adult populatio n was male dominated with a sex ratio of 1 female : 1.2 males with the mean size of males and females being similar. The lesser gurnard is a n iteroparous species with females maturing by the end of the first ye ar of life (195 mm L-T), thereafter spawning throughout the year with reproductive activity peaking over spring and late summer. The lesser gurnard appears to exhibit similar life-history patterns to other trig lid species in that it can be classified as a generalist. Generalistic life-history characteristics such as a fast growth rate, early sexual maturity at a relatively large size, a non-seasonal spawning pattern, feeding on a variety of prey organisms and the ability to inhabit var ious substrata could all contribute to it maintaining a high biomass o n the Agulhas Bank. (C) 1997 The Fisheries Society of the British Isle s.