THE SIGNIFICANCE OF LENGTH AT SEXUAL MATURITY, MESH SIZE AND CLOSED FISHING WATERS TO THE COMMERCIAL FISHERY FOR THE CATFISH CNIDOGLANIS-MACROCEPHALUS IN AUSTRALIAN ESTUARIES

The total lengths and numbers of Cnidoglanis macrocephalus caught in t he closed and open fishing waters of Wilson Inlet, using a gill net co mprising a wide range of mesh sizes, were recorded. These data were th en compared with those obtained for the commercial fishery. The result s strongly indicate that (I) the density and percentage contribution o f large fish are lower in open than in closed fishing waters, (II) fem ale fish were more readily caught than male fish and (III) the minimum legal mesh size and minimum legal length for C. macrocephalus should be increased to prevent fish being caught before they reach sexual mat urity.