Home-range, activity and distribution patterns of a temperate rock-reef fish, Cheilodactylus fuscus. Marine Biology

Abstract Red morwong (Cheilodactylus fuscus; Cheilo-dactylidae: Perciformes), are large temperate rocky reef fish that are patchily distributed in local aggregations of 3 to>100 fish. The home ranges and aggregating be-haviour of red morwong were investigated using external tags (n 114, over 35 mo) and ultrasonic transmitters (n 9 over 20 d) at coastal and estuarine sites in south-east Australia. Adult red morwong had a mean home range during the day of 1865 m2 (SE 268). Night movement, determined by ultrasonic telemetry, indicat-ed a significantly greater mean home range of 3639 m2 (SE 416). Home range did not dier significantly with size or sex. Fish movements were greatest and ag-gregation sizes varied most during the non-reproductive mid-summer period. Tagged fish (N 20) displaced 200 to 900 m returned in 1 to 3 d to the point of capture, often traversing open sand habitat and other aggrega-tions. During the day, fish were commonly found on bouldered habitat. During the night, these site-specific aggregations fragmented as fish dispersed over a variety of substrata, with crepuscular peaks in activity. There-fore, estimates of habitat-specificity and feeding patterns collected only by day may give misleading results