LIFE HISTORY ASPECTS OF THE WEST AUSTRALIAN SALAMANDERFISH, LEPIDOGALAXIAS SALAMANDROIDES MEES

WA Museum Records and Supplements | Updated 1 decade ago

Abstract: A field study of the ecology and general life history of the West Australian salamanderfish, Lepidogalaxias salamandroides, was conducted near Northcliffe, Western Australia, during 1986. This species mainly occurs between the Blackwood and Kent rivers, a linear distance of about 180 km. Circumstantial evidence for aestivation including the reappearance of fish in formerly dry pools immediately after a rainfall is presented. Monthly sampling provided data on size-sex composition, population structure, growth rates and diet. Most individuals captured were either juveniles under 25 mm SL (31.6%) or small adults, 25-39 mm SL (55.6%). Most fish probably live two years but a few may reach four years. The largest female was 67 mm and the largest male taken was 53 mm SL. Males could be distinguished from females at 25 mm SL. Females were generally larger than males and the overall sex ratio was approximately 1:1. Length-frequency analysis showed two generations in the population during September-January. The largest fish disappeared from the population in January. New recruits appeared in September-October and were most numerous in November. Juveniles and small adults dominated the population in January-February. Adult females grow about 2.2 mm/month from May-January, and juveniles increase 0.8 mm/month from September-January. The diet consisted mainly of the larval stages of chironomid midges and small crustaceans.