Length - weight relationships of freshwater fish from the Murray-Darling River System in inland New South Wales, with particular reference to the Golden PerchMacquaria ambigua

Abstract

Length - weight relationships for 29 fish species occurring in the Murray-Darling River System in inland NSW were determined using data collected principally between 1957 and 1970. In Golden Perch Macquaria ambigua, this relationship is examined with regard to locality, year and sex. In the Murrumbidgee River large females were more rotund than males. In the Murray River fish caught in November appeared to be more rotund than those caught in September supporting an increase in ovary size to be expected at this time of year, and 1960 fish were more rotund than fish from 1963 and 1964 also reflecting time of year and river heights. Twenty one of the species were examined with regard to all fish and sex differences. The remaining eight were examined for all fish combined only. In most cases a single curve adequately describes the relationship for each species, except when the population includes large numbers of maturing females or when substantial sexual dimorphism occurs, such as in Philypnodon grandiceps ...