TREVALLY, BLUDGER
The bludger trevally is a widespread species of large marine fish in the jack family, Carangidae. The bludger is of intermediate importance to fisheries throughout its range, taken by hook and line and variousnetting methods. It is of some value to anglers also, considered a good gamefish, but generally regarded as poor eating due to its soft oily flesh, which is used as bait by many anglers. The name ‘bludger’ is said to either refer to the blunt head of the species, or the destination of the fish when caught by professional fishermen who treat the fish as discard. It can reach a recorded maximum weight of 14.5 kg
The bludger has a body shape very similar to the yellowspotted trevally, being more elongated and subcylindricall than most of the genus Carangoides. As a juvenile, the fish is ovate, becoming more elongated with age, with the convex dorsal profile of the head and nape becoming less steep with age also. The dorsal fin is in two distinct parts, the first consisting of 8 spines while the second is composed of 1 spines and 28 to 32 soft rays, with the anterior lobe of this fin being shorter than the head length. The anal fin has two anteriorly detached spines followed by 1 spine attached to 24 to 26 soft rays and the pelvic fin has 1 spine and 18 to 20 soft rays. The lateral line has a gentle anterior arch which is slightly longer than the straight section of the lateral line, with the intersection below the sixteenth to twentieth soft ray of the dorsal fin. The curved section contains 78 to 80 scales while the straight section consists of 15 to 19 scales and 21 to 27 scutes. The breast is scaleless until the origin of the pelvic fins and up to the origin of the pectoral fins. In adults, the mouth cleft is level with the eye, with the both jaws containing bands of villiform teeth which become wider anteriorly. There are 27 to 31 gill rakers in total and 25 vertebrae.
The species has a rather soft mouth and weak jaws, limiting the types of prey available to it, with studies showing prawns, small crabs, mantis shrimps and small fish are its main prey. Taken by hook and line as well as gill nets and various types of fish trap. Separate catch statistics are not kept for the species, as it is often not distinguished from other trevallies. The blugder is also of some interest to anglers, although the level of interest differs between countries. In South Africa it is considered a good catch by boat anglers and spearfishermen and is generally regarded as high quality table fare. In Australia it is still considered a good gamefish.
Internationally
The bludger trevally is distributed throughout the tropical to subtropical regions of the Indian and west Pacific Oceans, ranging from South Africa in the west, along east Africa and north to the Red Sea. Its distribution in the Indian Ocean extends east to India, South East Asia, Indonesia and as far south as northern Australia. In the Pacific Ocean, it extends as far north as Japan and out to New Caledonia, Tonga and the Kapingamarangi Atoll.
The bludger inhabits moderately deep offshore waters on rocky and coral reef structures, rarely found in inshore waters.
Australia
The bludger trevally is present in the northern shores of Australia. They are found from north west Western Australia around the tropical north to the Great Barrier Reef Queensland.