Species

Giant trevally

Giant trevally, GT to anglers, ulua in Hawaii. The largest jack of its genus: a thickset reef predator that smashes poppers on the surface and draws anglers to the Seychelles, Mozambique, Zanzibar and Oman.

Caranx ignobilis

Photo: Dr. Dwayne Meadows, NOAA/NMFS/OPR, Wikimedia Commons, Public domain, adjusted to 3:2

Spawning: In the warmer months, in southern Africa from July to March with a peak from November to March, also timed by the lunar cycle; large schools spawn over reefs and banks (Wikipedia). Matures at 54 to 61 cm and three to four years (Wikipedia), FishBase gives 60 cm.
Typical method: Popping and stickbait fishing along reef edges (Wikipedia)
Top bait: Large popper

Plan a day fishing for Giant trevally

How to recognise it

Steep, blunt head profile, deep and laterally compressed body
Strong scutes along the lateral line in front of the deeply forked tail
Silver-grey, large males often almost black; no black spot on the gill cover, breast scaleless except for a patch in front of the pelvic fins

Easily confused with: The Atlantic crevalle jack (Caranx hippos) looks similar and was long confused with it (Wikipedia), but lives in the Atlantic. The smaller bluefin trevally (Caranx melampygus) has blue fins and hybridises with the giant trevally in Hawaii (FishBase, Wikipedia). In South African estuaries juveniles often school with the brassy trevally (Caranx papuensis) (Wikipedia).

How to catch it

Methods: Popping and stickbait fishing along reef edges (Wikipedia), Jigging over banks and drop-offs (Wikipedia), Fly fishing on the flats, for example in the Seychelles (rule of thumb), Bait fishing with baitfish or squid on strong tackle (Wikipedia)

Baits: Large popper, Stickbait, Metal jig, Live baitfish, Large streamer (fly)

Most active at dawn and dusk (Wikipedia, for South Africa and Hawaii). The best travel season depends on the venue; ask your operator before booking (rule of thumb).

Habitat and food

Indo-Pacific from the Red Sea and East Africa to Hawaii and the Marquesas, north to southern Japan, south to northern Australia (FishBase); its western limit is the southern tip of South Africa, plus island groups such as the Maldives, Seychelles and Madagascar (Wikipedia). Reefs, lagoons, bays, flats and channels at 10 to 188 m (FishBase); older fish move to outer reefs and drop-offs, often deeper than 80 m (Wikipedia). Juveniles live in estuaries, even upper river reaches and coastal lakes, in South Africa at salinities of 0.5 to 38 ppt (Wikipedia). Destinations for anglers include the Seychelles, Mozambique, Tanzania (Zanzibar), South Africa, Oman and the Maldives.

Apex predator that eats mainly fish, plus crustaceans, cephalopods and molluscs (Wikipedia); also crabs and spiny lobsters at night (FishBase). Off South Africa it hunts mainly by day, especially at dawn and dusk, off Zanzibar mostly at night. On Farquhar Atoll (Seychelles) it leaps for fledgling sooty terns (Wikipedia).

Size and age

FishBase: max. 170 cm, commonly 100 cm, maximum published weight 80 kg; English and German Wikipedia give the same maximums. Fish over 50 kg are not uncommon in sport fishing according to Wikipedia. Otolith growth curves put a fish of about 1 m at around eight years and a 1.7 m fish at around 24 years (Wikipedia).

Protection and rules

Conservation status: IUCN: Least Concern (assessed 2015; FishBase). Numbers around the main Hawaiian Islands have fallen sharply (Wikipedia). South Africa: recreational fishing requires a permit (Marine Living Resources Act 1998, section 13); kingfishes (Caranx spp.) have no minimum size and a daily bag limit of 5, with at most 10 fish per day in total (GN R1111 of 1998, Annexure 7, version on acts.co.za, retrieved 21 October 2026; check the current version with the fisheries department DFFE before your trip). Many operators fish catch and release only (Wikipedia). Elsewhere check licences and rules with your operator and the authority before you travel.

Rules by country

Size limits, bag limits, seasons and licences are set by each country, in the USA by each state. Pescaday does not list these rules: check them with your operator and the national authority before you fish. Notes with sources are given above under conservation status. Fishing travel guide

In the kitchen

Table quality is rated from poor to excellent; large fish can carry ciguatera toxin, which is why it is rarely eaten in Hawaii (English and German Wikipedia, FishBase). Large GTs are best released (rule of thumb).

Sources (5)

Last checked 2026-10-22. Found a mistake? Write to [email protected].

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