Caranx melampygus is common on a range of lagoon, pinnacle and seaward reefs. While often alone, paired or in very small groups, sometimes this species forms large schools of hundreds of individuals that race along the seaward reef slope. Small schools can often be seen swimming in very shallow water under the small boat marina piers at Kwajalein, where they chase schooling baitfish. Larger individuals may cause ciguatera poisoning, and eating them should be avoided. A large jack, its maximum size is reported to be about 117cm, although more commonly they are around 60cm.
They will often hang around schools of caesionids such as these Pterocaesio tile, looking for an easy meal.
Large schools will occasionally swim past along the steep seaward reef slope, sometimes coming up to look while passing a diver.
Created 2 January 2018