Age and growth studies on barramundi, Lates calcarifer (Bloch), in Northern Australia

Abstract

The growth of L. calcarifer was investigated in five river systems in northern Australia. Pairs of scales taken at the time of tagging and upon recapture, and seasonal data on marginal scale increments were used to verify that checks were laid down annually. Checks were formed between September and December, depending on the particular river and year. A seasonal pattern in growth was apparent from the marginal increment data and from the seasonal growth data on age 0+ fish. Growth was most rapid in the wet season (January to March). For each river system, back-calculated length at age data were obtained. Also, von Bertalanffy growth curves were fitted to both the back-calculated length at age data and length increment data from tagging. Growth curves fitted to both types of data were compared within and between rivers. No overall growth curve for L. calcarifer was obtained as there was considerable variation in growth between rivers.