Animal Species:Cottonmouth Trevally, Uraspis secunda Poey, 1860

Fishes of the genus Uraspis can be distinguished by the brilliant white tongue and walls of the mouth.

Cottonmouth Trevally off Botany Bay

Cottonmouth Trevally off Botany Bay
Photographer: Heath Folpp © Heath Folpp

Standard Common Name

Cottonmouth Trevally

Alternative Name/s

Basset-hull's Trevally, Cottonmouth Jack


Fishes of the genus Uraspis can be distinguished from the other Australian species in the family Carangidae by the brilliant white tongue and inside walls of the mouth.

Two species are known from Australian waters, U.secunda and U.uraspis, the Whitemouth Trevally. They can be separated by the extent of the scaleless area on the breast (extends approximately half way to pectoral fin base vs. all the way to the pectoral fin base) and the shape (and scale count) of the curved part of the lateral line (curved lateral line (48-66 scales) usually shorter than straight portion vs. curved (61-82 scales) usually longer than straight). Juveniles of both species are usually banded.

Size range

The Cottonmouth Trevally grows to 44 cm in length.


It occurs worldwide in tropical and warm temperate marine waters. In Australia it is known from the central coast of Western Australia, around the tropical north and south to the southern coast of New South Wales.

The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums.  Source: Atlas of Living Australia.

Uraspis secunda

Distribution by collection data

Ozcam map of Cottonmouth Trevally specimens in the Australian Museums.

What does this mean?



What does this mean?


  1. Allen, G.R. 1997. Marine Fishes of Tropical Australia and South-east Asia. Western Australian Museum. Pp. 292. (for Uraspis uraspis)
  2. Gunn, J.S. 1990. A Revision of Selected Genera of the Family Carangidae (Pisces) from Australian Waters. Records of the Australian Museum. Supplement 12: 1-77.
  3. Hutchins, B. & R. Swainston. 1986. Sea Fishes of Southern Australia. Complete Field Guide for Anglers and Divers. Swainston Publishing. Pp. 180 (for Uraspis uraspis).
  4. Smith-Vaniz, W.F. in Carpenter, K.E. & V.H. Niem. 1999. The Living Marine Resources of the Western Central Pacific. Volume 4. Bony fishes part 2 (Mugilidae to Carangidae). FAO. Rome Pp. iii-v, 2069-2790.

Mark McGrouther , Collection Manager, Ichthyology
Last Updated:

Tags Fishes, Ichthyology, Cottonmouth Trevally, Uraspis secunda, Carangidae, white tongue, Basset-hull's Trevally, Cottonmouth Jack, 30 cm - 1 m, tropical water, temperate water, marine,


Mark McGrouther - 3.04 PM, 06 April 2011

Hi Cameron.  Thank you so much for your adding your comment and the great image.  I'm delighted to hear that the specimen was identified by Sue Morrison of the Western Australian Museum.  Having a microscope and the specimen in hand certainly makes things easier!  According to the Australian Faunal Directory page, in addition to being found on the east coast, Uraspis secunda is recorded from the Northwest Shelf, of Western Australia, so as we discussed previously, your fish represents a significant southward range extension.

SchafferLoaders - 2.04 PM, 06 April 2011
Hi Everyone, This is a story about a big extension on the range of Uraspis secunda, or cottonmouth trevally, caught off the coast of Perth, Western Australia. The unusually strong Leeuwin current in 2011 seems to have pushed many pelagics and northern warm water species further south. Date specimen collected: 17 March 2011 (I think). Location: FAD approximately 20km west of Rottnest Island Name of FAD: Possibly Fremantle sailing fad Depth: approximately 200m Fishing method: free diving with rubber powered spear gun Anecdote: The weather was good so we decided to do a spear fishing trip (organized by Dstick) to the FADS in search of Dolphin fish (mahi mahi). The Leeuwin current has been particularly strong and a friend caught a state record dolphin fish the week before. We entered the water about 11am after having motor problems on the way out and spent a few hours looking for big dolphin fish, but only small dolphin fish were about. I observed two trevally and 5 leatherjackets staying in close to the FAD itself, the leatherjackets generally staying within a 4m perimeter of the FAD and in the top 2-5m of the water column. The trevally would generally stay within 3m of the FAD and never rise above 5m in the water column. Every time the trevally were approached however they went to around 15m depth and only returned close to the top 5m of water after leaving. I’d never seen any trevally like this before so decided to shoot one and keep it for identification purposes as it was just so unusual. One guy even thought it was some sort of luderick as it had similar ludrick shaped bands on it. The pectoral fins however definitely identified it as a trevally species. No large Dolphin fish were about so I decided to sneak up as far as possible on one of the trevally and take it. I speared the biggest trevally (612g) a bit low around the belly region but it held true and was humanely dispatched using the iki jimi method with a dive knife. I threaded the fish onto my float line and when passing the float line through the gill cavity and part of the gills were ripped off and drifted away. The specimen was stored and compared with Fil-O-Fish which seemed to identify it as Uraspis uraspis, however there was no record of Uraspis secunda in this book. After contacting Mark McGrouther from the Australian Museum it was positively identified as a Uraspis species but without a microscope it was hard to distinguish between U. uraspis or U. secunda. Sue Morrison, curator of the WA Museum has identified the species most likely as U. secunda. The specimen is now in the care of the WA Museum. Cheers, Cameron Moir - Schaffer Loaders

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