Contributions to the biology of the Cape gurnard, Trigla capensis (Pisces : Triglidae): age, growth and reproduction

Abstract

Study of otoliths of the Cape gurnard,Trigla capensis, has established that the rings are annular. An opaque zone is formed from February to Jury and a hyaline zone during the spawning season from August to March. Females grow faster than males. The Von Bertalanffy growth equation of the females was found to be

L_t = 71,4(1-e^{0 ,100(t + 0,41)}) and for the males

L_t = 58,6(1-e^{-0, 100(t + 0,28)}). Male fishes are sexually mature at a total length of37cm at the end of the fifth year. The female fishes are all sexually mature at a total length of 35 cm at the age of four years.