Blue Runner
Caranx crysos
    Ecological Descriptors
Habitat Size (cm) Diet Behaviour Sex 
Pel 75 Pisc, Cru Sh F
Adults: Body light blue to olive above, silvery below with a black spot at top corner of operculum.
Tips of tail black.
Juveniles: Often  have 7 vertical dark bars on body.

The Blue Runner is a pelagic species which forms schools primarily inshore; it is not  generally common around reefs. It has a depth range of 0-100m (0-280ft) and juveniles are found beneath floating Sargassum mats. These mats provide this species both with prey and protection from predators. It feeds on shrimps, fishes and other invertebrates.

Life Cycle:
Sexual maturity is reached at different lengths for the blue runner depending on where it is found. There are two main spawning peaks for this species; June, July and August are the months associated with the main one while the secondary one is in October. There is evidence however, that suggests that spawning occurs yearlong offshore. Females produce from 41,000-1,000,000 eggs, with larger ones producing more. These along with the larvae are pelagic. At the larval stage, it has distinguishing features
such as a shallow body and heavy pigment present on the head and body. Several dark vertical bars are also present along the body during this early juvenile stage. Does not take care of its young. Juveniles remain offshore and live in water about 15m deep or congregate around floating masses such as Sargassum seaweed. Congregations also form around oil platforms.
Blue Runner
Blue Runner Juvenile
Blue Runner