Flagtail Glassfish, Ambassis miops Günther 1872

Other Names: Flag-tailed Glassfish, Myops Glassy Perchlet

Summary:

The Flagtail Glassfish is known from only a few coastal sites along the North Queensland coast. This species is widely distributed outside of Australia and as such is believed to have a marine larval stage. One of the distinguishing features of this transparent species is a tiny spine situated above the rear corner of the eye.

Cite this page as:

Thompson, V.J. & Bray, D.J. 2021, Ambassis miops in Fishes of Australia, accessed 04 Jul 2025, https://fishesofaustralia.net.au/home/species/1585

Flagtail Glassfish, Ambassis miops Günther 1872

More Info

Distribution	In Australia known only from coastal areas of the Cape York Peninsula Queensland, from the Starcke River (14º49´S) to Cairns (16º55´S). Also known from Indonesia, New Guinea, New Caledonia and Rarotoga. Tropical, aggregating in clear, flowing freshwater creeks, mangroves and estuaries within 20 km of the sea.
Features	D VIII, 9-10; A III, 9-10; P 13-14; Body ovate, compressed, relatively slender; greatest body depth 33.4-38.6 % SL; head length 35.5 to 38.6; snout length 6.7 to 9.1; eye relatively large, diameter 12.9 to 15.0; mouth large, oblique; single supraorbital spine; 2 transverse scale rows on cheek; lateral line usually continuous from upper edge of gill opening to caudal fin base; nasal spine present; Scales cycloid, large; horizontal scale rows 9-10; vertical scale rows 28-30; lateral line scales 28-30. Dorsal fin deeply notched, origin forward of ventral fins; first dorsal spine small, projecting forward; anal fin opposite soft rays of dorsal; height of first dorsal fin 24.6 to 28.3; third dorsal spine slightly longer than second dorsal spine; third anal spine longer than second anal spine; anal and dorsal fins with scaly basal sheath; pectoral fins of moderate size; ventral fins large; caudal fin strongly forked, lobes rounded.
Size	To 8 cm SL.
Colour	Semi-transparent with a silvery/bronze midlateral stripe and dark scale margins that form a faint reticulated pattern dorsally and laterally. Fins mainly clear but sometimes with yellow/bronze on caudal and anterior part of dorsal fin.
Feeding	Feed mainly on aquatic insects but also on smaller fishes, crustaceans and some algae from woody debris.
Biology	Little is known of the reproductive biology of this species but because of its broad distribution it is thought to have a marine larval phase.
Conservation	Not listed on the IUCN Red List of Threatened Species. Not listed under the Australian EPBC Act.
Remarks	This species is locally abundant but found only from a few sites in Australia.
Etymology	The specific name is from the Greek meion (= less, little) and opsis (= eye), in reference to the small spine above the eye.
Species Citation	Ambassis miops Günther, A. (1872). Report on several collections of fishes recently obtained for the British Museum. Proc. Zool. Soc. Lond. 1871(3): 652–675 pls 53–70 [655]. Rarotonga, Cook Ils.
Author	Thompson, V.J. & Bray, D.J. 2021

Flagtail Glassfish, Ambassis miops Günther 1872

References

Allen, G.R. (1989). Freshwater Fishes of Australia. Neptune, New Jersey : T.F.H. Publications pp. 1–240

Allen, G.R., Midgley, S.H. & Allen, M. (2002). Field guide to the freshwater fishes of Australia. Perth : Western Australian Museum 394 pp.

Pusey, B.J., Arthington, A.H. & Read, M.G. 1995. Species richness and spatial variation in fish assemblage structure in two rivers of the wet tropics of northern Queensland, Australia. Environmental Biology of Fish 42(2): 181-199.

Larson, H. 2012. Ambassis miops. The IUCN Red List of Threatened Species. Version 2015.1. . Downloaded on 11 June 2015.

Pusey B., Kennard M. & Arthington A. (2004) Freshwater Fishes of North-Eastern Australia. CSIRO Publishing, Collingwood, Victoria.

Pusey, B.J., M.G. Read & A.H. Arthington. 1995. The feeding ecology of freshwater fishes in two rivers of the Australian wet tropics. Environmental Biology of Fish 43(1): 85-103.