Blue Weed-whiting, Haletta semifasciata (Valenciennes 1840)

Other Names: Blue Rock Whiting, Blue Weed Whiting, Blue-arsed Whiting, Grass Whiting, Rock Whiting, Stranger, Stranger Whiting, Weed Whiting, Weedy Whiting

A male Blue Weed Whiting, Haletta semifasciata. Source: Rudie H. Kuiter / Aquatic Photographics. License: All rights reserved


A slender weed whiting with long-based low dorsal and anal fins, a long pointed snout, and jaw teeth fused into a beak-like structure. Juveniles and females are greenish with a silver stripe along the sides. Males are bluish with faint bars or markings on the sides and a blue area around the anus.

Although very common in parts of its range, this well-camouflaged species is rarely seen.

Cite this page as:
Dianne J. Bray, Haletta semifasciata in Fishes of Australia, accessed 07 Jul 2022,

Blue Weed-whiting, Haletta semifasciata (Valenciennes 1840)

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Endemic to southern Australia from the Sydney region, New South Wales, to Cervantes Australia, and south to Stringers Cove, Dover, Tasmania. Inhabits bays, harbours and coastal waters, usually in seagrass beds and on shallow reefs with good algal cover, in depths of 1-15 m. may form large schools over sandy and seagrass bottoms in estuaries and sheltered bays.


Meristic features: Dorsal-fin spines/rays XVII-XVIII, 12-14; Anal-fin spines/rays III, 10-12; Caudal-fin rays 12-14; Pectoral-fin rays 14-16; Pelvic-fin spines/rays I, 4;
Lateral line 47-62.

Body long, slender, with long-based low dorsal and anal fins; snout long, pointed; teeth in jaws fused. Juveniles and females greenish with a silver stripe along the sides, males bluish with faint bars or markings on the sides and a blue area around the anus.


Feeds on polychaete worms, and also bivalve and gastropod molluscs, crustaceans (crab and amphipods), and ophiuroids. Also consumes some algae and seagrass (mostly Zostera).


Protogynous hermaphrodites with females changing sex to become males.


Sometimes taken as by-catch in commercial nets and is occasionally taken by anglers. Occasionally found in markets.

Species Citation

Odax semifasciatus Valenciennes, 1840, Histoire Naturelle des Poissons 14: 299, pl. 407. Type locality: in original as "Mers des Indes" - probably Tasmania.


Dianne J. Bray

Blue Weed-whiting, Haletta semifasciata (Valenciennes 1840)


Clements, K.D., Alfaro, M.E., Fessler, J.L. & Westneat, M.W. 2004. Relationships of the temperate Australasian labrid fish tribe Odacini (Perciformes; Teleostei). Molecular Phylogenetics and Evolution 32: 575–587.

Edgar, G.J. & Shaw, C. 1995. The production and tropic ecology of shallow-water fish assemblages in Southern Australia. II. Diets of fishes and tropic relationships between fishes and benthos at Western Port, Victoria. Journal of Experimental Marine Biology and Ecology 194: 83-106.

Gomon, M.F. & Paxton, J.R. 1985. A revision of the Odacidae, a temperate Australian-New Zealand labroid fish family. Indo-Pacific Fishes 8: 57.

Gomon, M.F., Bray, D.J. & Kuiter, R.H. 2008. Fishes of Australia’s Southern Coast. Reed New Holland, Museum Victoria, Chatswood, NSW, Australia.

Jones, G.K., Baker, J.L., Edyvane, K. & Wright, G.J. 1996. Nearshore fish community of the Port River-Barker Inlet Estuary, South Australia. 1. Effect of thermal effluent on the fish community structure, and distribution and growth of economically important fish species. Marine and Freshwater Research 47(6): 785-799.

Kuiter, R.H. 1993. Coastal Fishes of South-eastern Australia. Bathurst : Crawford House Press 437 pp.

Kuiter, R.H. 1996. Guide to Sea Fishes of Australia. A comprehensive reference for divers and fishermen. Sydney, NSW, Australia : New Holland Publishers xvii, 434 pp.

MacArthur, L.D. & Hyndes, G.A. 2001. Differential use of seagrass assemblages by a suite of odacid species. Estuarine, Coastal and Shelf Science 52: 79-90.

MacArthur, L.D. & Hyndes, G.A. 2007. Varying foraging strategies of Labridae in seagrass habitats: herbivory in temperate seagrass meadows? Journal of Experimental Marine Biology and Ecology 340: 247-258.

Neira, F.J., A.G. Miskiewicz & T. Trnski. 1998. Larvae of temperate Australian fishes: laboratory guide for larval fish identification. University of Western Australia Press. 474 pp.

Russell, B., Clements, K.D., Choat, J.H., Rocha, L.A., Myers, R., Lazuardi, M.E., Muljadi, A., Pardede, S. & Rahardjo, P. 2012. Haletta semifasciata. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <>. Downloaded on 04 February 2014.

Quick Facts

CAAB Code:37385009

Biology:Changes sex

Conservation:IUCN Least Concern

Depth:1-15 m

Fishing:Minor commercial, recreational

Max Size:41 cm


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