Slimy Mackerel (Scomber australasicus) — identification, habitat & look-alikes

Slimy Mackerel is a schooling fish of coastal and island waters. Dark wavy lines cover the back, while gray spots or broken lines on the pale belly help distinguish it from Pacific Chub Mackerel. It is also called Spotted Chub Mackerel and Blue Mackerel.

Appearance

Appearance: The back has narrow, dark wavy lines; the pale underside can carry broken gray markings. Adults can reach about 20 in (50 cm).

Look-alikes

Pacific Chub MackerelScomber japonicus

Look below the dark wavy back: Slimy Mackerel has gray spots or broken lines on the pale belly, while Pacific Chub Mackerel usually has a plainer silver belly. A clear side view helps; distant school photos may be inconclusive.

Why they get mixed upBoth have streamlined bodies and dark wavy markings across the back.

Where it lives

Typical habitats: coastal water
open water around islands
Range: In the United States it is recorded around Hawaii. Its wider range runs through the western Pacific from Japan to Australia and New Zealand, with records off Mexico as well.

Behavior

Diet: It feeds on drifting and, as an adult, also takes small fish and squid.
Social life: Fish of similar size gather in schools.

Conservation

IUCN Red List: LCLeast ConcernLow risk of extinction

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