Variable Threefin, Forsterygion varium (Forster 1801)

Other Names: Many-rayed Threefin, Striped Triplefin, Variable Triplefin

A Variable Threefin, Forsterygion varium, in Charlotte Cove, Tasmania, March 2013. Source: Ian Shaw / License: CC by Attribution-NonCommercial

A pale brown to reddish triplefin with broad reddish-brown to blackish saddles, not extending onto the ventral surface. The Variable Threefin was introduced to southern Tasmania from New Zealand - possibly in shipments of oysters.

Cite this page as:
Dianne J. Bray, Forsterygion varium in Fishes of Australia, accessed 13 Jun 2024,

Variable Threefin, Forsterygion varium (Forster 1801)

More Info


Introduced to southern Tasmania from New Zealand, possibly in shipments of oysters (Hickey et al. 2004). Inhabits rock pools and semi-exposed and exposed rocky reefs in depths to about 30 m (usually 0-10 m).


Feeds on small crustaceans and fishes.


Males attract females to their nesting sites. Females deposits their adhesive eggs onto rocky or shelly surfaces where they are fertilised by the male. The developing eggs are guarded by the male until the planktonic larvae hatch.

Species Citation

Blennius varius Forster 1801, Systema Ichthyologiae: 178. Type locality: Queen Charlotte Sound, South Island, New Zealand (Neotype).


Dianne J. Bray

Variable Threefin, Forsterygion varium (Forster 1801)


Clements, K.D. 2014. Forsterygion varium. The IUCN Red List of Threatened Species 2014: e.T179014A1559417. Downloaded on 09 March 2016.

Connell, SG & Jones, GP. 1991. The influence of habitat complexity on postrecruitment processes in a temperate reef fish population. Journal of Experimental Marine Biology and Ecology 151(2): 271-294.

Edgar, G.J. 2008. Australian Marine Life: the plants and animals of temperate waters. Sydney : Reed New Holland 2nd edn, 624 pp. 

Edgar, G.J., Last, P.R. & Wells, M.W. 1982. Coastal Fishes of Tasmania and Bass Strait. Hobart : Cat & Fiddle Press 175 pp. (as Forsterygion multiradiatum)

Feary, D.A. & Clements, K.D. 2006. Habitat use by triplefin (Tripterygiidae) on rocky reefs in New Zealand. Journal of Fish Biology 69(4): 1031-1046. 

Forster, J.R. in Bloch, M.E. & Schneider, J.G. 1801. Systema Ichthyologiae Iconibus ex Illustratum. Berlin. 584 pp. 110 pls 

Francis, M.P. 1996. Geographic distribution of marine reef fishes in the New Zealand region. New Zealand Journal of Marine and Freshwater Research 30(1-2): 35-55. 

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

Hardy, G. 1989. The genus Forsterygion Whitley & Phillipps, 1939 (Pisces: Tripterygiidae) in New Zealand and Australia, with descriptions of two new species. Journal of Natural History 23(3): 491-512.

Hickey, A.J.R., Lavery, S.D. Eyton, S.R. & Clements, K.D. 2004. Verifying invasive marine fish species using molecular techniques: A model example using triplefin fishes (Family Tripterygiidae). New Zealand Journal of Marine and Freshwater Research 38: 439-446. PDF Open access

Hutchins, J.B. & Swainston, R. 1986. Sea Fishes of Southern Australia. Complete field guide for anglers and divers. Perth : Swainston Publishing 180 pp. (as Forsterygion multimaculatum

Jawad, L.A. 2008. Second revision of the New Zealand triplefin genus Forsterygion Whitley and Phillips, 1939 (Pisces: Tripterygiidae). Journal of Natural History 42(47-48): 2943-2989.

Last, P.R., Scott, E.O.G. & Talbot, F.H. 1983. Fishes of Tasmania. Hobart : Tasmanian Fisheries Development Authority 563 pp. figs. (as Forsterygion multiradiatum)

Paulin, C.D. & Roberts, C.D. 1992. The rockpool fishes of New Zealand. Te ika aaria o Aotearoa. Wellington : Museum of New Zealand Te Papa Tongarewa 177 pp.

Paulin, C., Stewart, A., Roberts, C. & McMillan, P. 1989. New Zealand fish: a complete guide. National Museum of New Zealand Miscellaneous Series 19: 1-279.

Paul, L.J. 1992. Age and growth studies of New Zealand marine fishes, 1921-90: a review and bibliography. Australian Journal of Marine and Freshwater Research 43: 879-912.

Russell, B.C. 1983. The food and feeding habits of rocky reef fish of north-eastern New Zealand. New Zealand Journal of Marine and Freshwater Research 17(2): 121-145. 

Scott, E.O.G. 1977. Observations on some Tasmanian fishes. Part 23. Papers and Proceedings of the Royal Society of Tasmania 111: 111-180 figs 1-3 (p. 153, as Forsterygion multiradiatum)

Taylor, R.B. & Willis, T.J. 1998. Relationships amongst length, weight and growth of north-eastern New Zealand reef fishes. Marine and Freshwater Research 49: 255-260. 

Thompson, S. 1979. Ecological and behavioural factors influencing the distribution and abundance patterns of tripterygiid fishes with particular reference to Tripterygion varium. M.Sc. Thesis, Univ. Auckland.

Quick Facts

CAAB Code:37415003

Conservation:IUCN Least Concern

Depth:0-33 m (commonly 0-10 m)

Habitat:Reef associated

Max Size:13 cm SL


Species Image Gallery

Species Maps

CAAB distribution map