Animal Species:Largemouth Threefin, Ucla xenogrammus Holleman, 1993

Like all tripterigyid fishes, the Largemouth Threefin has three dorsal fins. The species occurs in coral reef and tropical inshore waters from the eastern Indian Ocean to the Central Pacific.

Largemouth Threefin at Lizard Island

Largemouth Threefin at Lizard Island
Photographer: Johanna Werminghausen © Johanna Werminghausen

Standard Common Name

Largemouth Threefin

Alternative Name/s

Largemouth Triplefin


Like all tripterigyid fishes, the Largemouth Threefin has three dorsal fins. The first dorsal fin has three spines. The species has a translucent to whitish body with small black spots, white bars and irregular red blotches. The fins have white and red bands. There is a Y-shaped maroon line on either side of the snout that bifurcates at the nostrils.

Paratypes of this species are stored in the Australian Museum Fish Collection (AMS I.21903–033, I.20779–166, I.20774–011). The holotype was collected at Lizard Island, Queensland.

Size range

In comparison to other Threefins, it is quite large, growing to almost 5 cm in length.


The species occurs from the eastern Indian Ocean to the Central Pacific. In Australia it is known from south-western Western Australia to the Northern Territory including the offshore islands of north-western Western Australia. It is also found from the northern to central coasts of Queensland and offshore islands in the Coral Sea.

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

Ucla xenogrammus

Distribution by collection data

Ozcam map of Largemouth Threefin specimens in the Australian Museum.

What does this mean?


The species is found on coral reefs and tropical inshore waters.



What does this mean?


  1. Fricke, R. 1994. Tripterygiid fishes of Australia, New Zealand and the Southwest Pacific Ocean, with descriptions of 2 new genera and 16 species (Teleostei). Theses Zoologicae. 24: 1–585 figs 1–130.
  2. Hoese, D.F., Bray, D.J., Paxton, J.R. & G.R. Allen. 2006. Fishes. In Beesley, P.L. & A. Wells. (eds) Zoological Catalogue of Australia. Volume 35. ABRS & CSIRO Publishing: Australia. parts 1-3, pages 1-2178.
  3. Randall, J.E. 2005. Reef and Shore Fishes of the South Pacific. University of Hawai'i Press. Pp. 707.
  4. Randall, J.E., Allen, G.R. & R.C. Steene. 1997. Fishes of the Great Barrier Reef and Coral Sea. Crawford House Press. Pp. 557.

Mark McGrouther , Collection Manager, Ichthyology
Last Updated:

Tags Fishes, Ichthyology, Largemouth Threefin, Ucla xenogrammus, Tripterygiidae, white, black, red, coral reef, marine, adult, dashes, Y-shaped,