Home range, activity and distribution patterns of a temperate rocky-reef fish, Cheilodactylus fuscus

Red morwong (Cheilodactylus fuscus; Cheilodactylidae: Perciformes), are lar ge temperate rocky reef fish that are patchily distributed in local aggrega tions of 3 to > 100 fish. The home ranges and aggregating behaviour of red morwong were investigated using external tags (n = 114, over 35 mo) and ult rasonic transmitters (n = 9 over 20 d) at coastal and estuarine sites in so utheast Australia. Adult red morwong had a mean home range during the day o f 1865 m(2) (SE = 268). Night movement, determined by ultrasonic telemetry, indicated a significantly greater mean home range of 3639 m(2) (SE = 416). Home range did not differ significantly with size or sex. Fish movements w ere greatest and aggregation 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 ot her aggregations. During the day, fish were commonly found on bouldered hab itat. During the night, these site-specific aggregations fragmented as fish dispersed over a variety of substrata, with crepuscular peaks in activity. Therefore, estimates of habitat-specificity and feeding patterns collected only by day may give misleading results.