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Silvermouth Trevally

Silvermouth Trevally

Ulua Aurochs

Quick Facts

Scientific name Ulua Aurochs

Other names Blackcrested Trevally, Longraker Trevally, Mirrormouthed Trevally

Size Up to 50 cm (19.6 in)

Weight Up to 1.25 kg (2.75 lb)

Distribution

Habitat & AU Distribution Coastal & oceanic waters, schooling towards the bottom & middle of the water column

Depth Range 0 - 80+ m (260+ ft)

Interesting Info

The Silvermouth Trevally is named for its shiny silver mouth and tongue, which gleam like polished metal when open.
It grows up to about 50 cm (20 in) and weighs around 1.25 kg (2.7 lb), making it smaller than many other trevallies.
In Australia it is found from Geraldton in Western Australia across the north to Ayr in Queensland, including the Arafura Sea.
Outside Australia, it lives in the tropical western Pacific, including southern New Guinea and as far north as Taiwan.
Juveniles have 5–6 dark vertical bars on their body that fade as they mature.
Adults are bluish to silvery-blue on top and bright silver below, with blackish tips on parts of the dorsal and anal fins.
They have unusually long, feather-like gill rakers that project into the mouth beside the tongue, a feature not common in most trevallies.
Older individuals often develop a prominent chin that sticks out slightly beyond the upper jaw.
Silvermouth Trevallies feed mainly on small crustaceans and squid, picking prey from mid-water or near the seabed.
They form loose schools in coastal waters, sometimes mixing with other trevallies.
Juveniles often gather in shallow reef flats, while adults prefer slightly deeper open coastal zones.
Divers and snorkellers may spot them flashing their distinctive silver mouths when feeding or turning suddenly.
Spawning for the Silvermouth Trevally hasn’t been formally studied. It likely breeds offshore in warmer months, releasing eggs into open water where they drift as plankton.
Their maximum lifespan isn’t well studied, but related trevally species can live 10–15 years.
They are occasionally taken in small fisheries or as bycatch but are not a major commercial species.
The species was first described in 1915 by Australian ichthyologist James Douglas Ogilby.

Species Interaction

Recreational Fishing, Snorkelling & Diving

For recreational fishers, the Silvermouth Trevally is not a common target but is sometimes caught as bycatch. Snorkellers and divers may see schools of them around reef edges or in mid-water over open coastal zones. They’re appreciated when seen because of their shiny mouth and schooling behaviour—but they’re not one of the big show-fish.

Scientific Classification

Kingdom: Animalia

Phylum: Chordata

Class: Actinopterygii

Order: Carangiformes

Family: Carangidae

Genus: Ulua

Species: Ulua aurochs

Conservation Status

The Silvermouth Trevally is listed as Least Concern by the IUCN. It has a reasonably wide distribution across northern Australia and southern New Guinea, and there are no major known threats. However, being a coastal species, it depends on healthy reef and mid-water zones, and could be affected locally by overfishing or habitat degradation.

Fish Taste Quality

Silvermouth Trevally is edible and is eaten locally where caught. The flesh is lean and somewhat mild. It’s not highly prized compared to larger trevallies, but makes a decent table fish.

Taste Rating: 3/5