Spotted Blue Eye, Pseudomugil gertrudae Weber 1911

Other Names: Gertrude's Blue Eye, Gertrude's Blue-eye, Northern Blue-eye, Spotted Blue-eye

Spotted Blue Eyes, Pseudomugil gertrudae. Source: Dave Wilson. License: All rights reserved

A very small blue eye with a characteristic pattern of black spots on the dorsal, anal and caudal fins.

Cite this page as:
Dianne J. Bray & Vanessa J. Thompson, Pseudomugil gertrudae in Fishes of Australia, accessed 29 Mar 2023,

Spotted Blue Eye, Pseudomugil gertrudae Weber 1911

More Info


Several isolated populations occur in the Northern Territory and northern Queensland, from the Finniss River and Groote Eylandt, Northern Territory, and the Jardine River system, several small creeks at the tip of Cape York Peninsula, and the Murray Swamps near Tully, Queensland. Also in southern New Guinea.

Found in a range of freshwater habitats including small sandy or muddy-bottomed creeks, swamps and marshes, shady rainforest streams, lily lagoons, backwaters and overflows adjacent to larger rivers. Commonly aggregates in areas with abundant vegetation and woody debris.


Meristic features: Dorsal fin IV-VI + 6-8; Anal fin 9-12; Pectoral fin 8-11.

Body relatively elongate, laterally compressed; greatest body depth 21.9-25.5% SL; head length 24.2-28.1; snout length 4.0-5.4; eye diameter 8.5-10.3; mouth small with a protractile maxillary, gape greatly restricted by labial ligament; jaw teeth conical to caniniform, moderately large, strongly curved backwards; with or without one or more rows of teeth extending outside of mouth; vomer and palatines toothless.

Scales cycloid with well-developed radii; horizontal scale rows 6 or 7; vertical scale rows 25 to 28; cheek with 3-5 scales.

Two separate dorsal fins; first dorsal fin originating under tip of pectoral; anal fin originating under end of first dorsal and in front of second dorsal origin; dorsal and anal fins lack rigid spines; pectoral fins short and set in a horizontal plane; mature males with elongate anterior dorsal, anal, and pelvic fin rays.


To 3.8 cm SL.


Body silvery white to almost transparent to a pale tannish-yellow with a network of dark scale outlines, 3 horizontal black lines on the rear of the body, distinctive black spotting on the pale yellow median fins, and a blue eye. Males are usually more intensely spotted than females, and the first dorsal fin is usually yellow.


Feeds mostly on micro-crustaceans and insect larvae.


Breed opportunistically throughout the year. Males display to females by intensifying their colours and erecting their ornate fins. Breeding episodes last several days with females depositing 4-10 adhesive eggs per day amongst aquatic vegetation. Eggs are small and adhesive. Larvae hatch in 2-3 weeks; small at hatching (3.8-4.0 mm SL) but eyes and swim bladder are well developed and body is well pigmented.


A popular aquarium fish.


Not listed


Populations are considerably variable in colour, fin shape and size.

Similar Species

Similar to P. paskai found in New Guinea.


Pseudomugil is from the Greek pseudes meaning 'false' and the Latin mugil meaning a 'fish', most likely a Mullet. The species was described from Aru Island by Max Weber, Professor of Zoology at the University of Amsterdam and named gertrudae after the wife of Dr. Hugo Merton, a German naturalist who travelled through the Aru Islands.

Species Citation

Pseudomugil gertrudae Weber, 1911, Abh. Senckenb. Naturforsch. Ges. 34: 23. Type locality: Ngaiguli, Terangan, Aru lslands.


Dianne J. Bray & Vanessa J. Thompson

Spotted Blue Eye, Pseudomugil gertrudae Weber 1911


Allen G.R. 1980. A Generic Classification of the Rainbowfishes (Family Melanotaeniidae). Records of the Western Australian Museum 8(3): 449-490.

Allen, G.R. 1989. Freshwater Fishes of Australia. Neptune, New Jersey : T.F.H. Publications 240 pp., 63 pls.

Allen, G.R. 1991. Field guide to the freshwater fishes of New Guinea. Christensen Research Institute, Madang, Papua New Guinea.

Allen, G.R. & Cross, N.J. 1982. Rainbowfishes of Australia and Papua-New Guinea. New Jersey : T.F.H. Publications 142 pp. figs.

Allen, G.R., Midgley, S.H. & Allen, M. 2002. Field Guide to the Freshwater Fishes of Australia. Perth : Western Australian Museum 394 pp.

Allen, G.R., Unmack, P.J. & Hadiaty, R.K. 2016. Pseudomugil luminatus, a new species of Blue-eye (Teleostei: Pseudomugilidae) from southern New Guinea, with notes on P. gertrudae. Fishes of Sahul 30 (1): 950-961.

Cook, B.D., P.J. Unmack, J.A. Huey & J.M. Hughes. 2014. Origin of relict populations of freshwater fishes in northern Australia with common disjunct distributions (Pseudomugil gertrudae, Denariusa australis and Melanotaenia maccullochi). Freshwater Science 33: 263–272.

Grant, E.M. 2002. Guide to Fishes. Redcliffe : EM Grant Pty Ltd 880 pp.

Lake, J.S. 1978. Australian Freshwater Fishes. Melbourne : Thomas Nelson 160 pp. 140 figs.

Larson, H.K. & Martin, K.C. 1990. Freshwater Fishes of the Northern Territory. Northern Territory Museum of Arts and Sciences Handbook Series Number 1. Darwin : Northern Territory Museum of Arts and Sciences 102 pp. 73 figs.

Leggett, R. & Merrick, J.R. 1987. Australian Native Fishes for Aquariums. Artarmon : J.R. Merrick Publications 241 pp. 142 figs.

Merrick, J.R. & Schmida, G.E. 1984. Australian Freshwater Fishes Biology and Management. Sydney : J.R. Merrick 409 pp. figs 280 col. figs.

Pusey, B., Kennard, M. & Arthington, A. 2004. Freshwater fishes of north-eastern Australia. CSIRO publishing, Collingwood, Victoria 684 pp.

Saeed, B., Ivantsoff, W. & Allen, G.R. 1989. Taxonomic revision of the family Pseudomugilidae (Order Atheriniformes). Australian Journal of Marine and Freshwater Research 40: 719-787

Weber, M. 1911. Die Fische der Aru- und Kei-Inseln. Ein Beitrag zur Zoogeographie dieser Inseln. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft 34: 1-49 figs 1-11

Quick Facts

CAAB Code:37245001

Fishing:Aquarium fish


Max Size:4 cm SL

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