Blue Streamgoby, Sicyopterus lagocephalus (Pallas 1770)

Other Names: Blue Stream Goby, Rabbithead Cling-goby, Rabbit-headed Cling Goby

A male Blue Streamgoby, Sicyopterus lagocephalus, from Goodenough Island, Milne Bay Province, Papua New Guinea. Source: Gerald R. Allen. License: All rights reserved

Males become very colourful during the rainy season, with bluish to greenish sides, with an orange to red caudal fin. Females are brownish to greyish with a whitish belly, 6-8 dusky to blackish saddles often along the back and tail base, often dusky streaks and spots and a blackish mid-lateral stripe on the sides.
Found in fast-flowing coastal rainforest streams in northern Queensland where they cling to the rocky bottom with their fused pelvic fins.
Video of Blue Streamgobies showing breeding coloration in an aquarium.
Video of a male trying to entice a female into his nesting chamber.
Video of Blue Streamgobies in the wild on Sulawesi, Indonesia.

Cite this page as:
Gomon, M.F. & Bray, D.J. 2021, Sicyopterus lagocephalus in Fishes of Australia, accessed 20 Apr 2024,

Blue Streamgoby, Sicyopterus lagocephalus (Pallas 1770)

More Info


Occurs in the wet tropics, Queensland, from the Bloomfield River to the Nyleta Creek, south of Cairns. Elsewhere, the species occurs in the Indo-west-central Pacific: Comoros, Réunion, Mauritius (Mascarenes) and islands east to French Polynesia, north to southern Japan, south to New Caledonia. 
Adults inhabit moderate to fast-flowing, clear rainforest streams with rocky and boulder-strewn bottoms. Elsewhere, they occur in very steep, high gradient streams at altitudes to about 300 m, but also 600 m inland in streams that do not drop precipitously and are not occupied by more specialized inhabitants of higher gradient streams.


Dorsal fin VI-VII + I, 10-12; Anal fin 1, 10; Caudal fin 12-16; Pectoral fin 17-20; Pelvic fin I, 5; Tr Sc 14-20.
Body slender, elongate, depth 4.8-7.7 in SL, slightly compressed; caudal peduncle deep. Head small, length 3.7-5.0 in SL. Snout rounded, males with more bulbous snout. Eyes small. Mouth inferior, horizontal, reaching to below middle of eye; upper jaw with row of 39-87 flexible tricuspid teeth, lateral cusps rounded, medial cusps shorter than lateral cusps and sharply pointed; lower jaw with a single straight row of 1-9 conical teeth on each side, not curved and not meeting at symphysis; upper lip with inverted V-shaped cleft anteriorly and cleft midlaterally, ventral edge of upper lip usually smooth; lower lip mostly absent.
Lateral line absent; longitudinal series usually 49-59, ctenoid scales on flanks and caudal peduncle, cycloid along bases of dorsal and anal fins, cycloid on dorsal and ventral surfaces of caudal peduncle; posterior to hypural base usually ctenoid at base and cycloid distally. Predorsal scales 11-20, cycloid, those in anterior quarter smaller than posteriorly. Belly from anus to close to pelvic base covered with rather large cycloid scales, as on caudal peduncle; head, breast and pectoral base naked.
Two dorsal fins, membrane of first dorsal not connecting second, third spine filamentous, usually reaching only slightly beyond origin of second dorsal when depressed, spines 2, 3, and 4 in some males filamentous; anal fin opposite second dorsal; caudal fin rounded. Pelvic fins fully united into disc, frenum strong, disc adherent to belly between all 5 rays. Pectoral fin rays free dorsally, extending beyond membrane and not appearing feathery or silky, posterior margin rounded. Males with longer unpaired fins than females.


To around 12 cm SL.


Males usually bluish or greenish laterally; caudal fin orange or red during rainy seasons, yellow to pink, or greyish, during dry seasons; fins generally dusky, but highly variable; pectoral fins white; caudal fin orange or red, with dorsal and ventral margins bluish white, distinctive blackish or dusky horseshoe-shaped band, central 3-4 caudal rays blackish or dusky, usually extending to horseshoe-shaped band. Females brownish with white belly, 6-8 dusky to blackish saddles sometimes evident on dorsum and caudal peduncle; sides of body variously adorned with dusky streaks and spots, frequently blackish midlateral stripe extending from pectoral fin to hypural base. Ventral to midline region often with even rows of black spots. first dorsal spines sometimes whitish distally; dorsal and ventral margins of caudal fin and distal margin of anal fin whitish or bluish; pectoral fin sometimes whitish ventrally.


The adults live in freshwater habitats and reproduction is apparently triggered by seasonal increases in rainfall and therefore varying considerably throughout range. Spawning occurs in rivers and streams and the newly hatched larvae are carried downstream to the sea where they spend about 18 weeks. 

Post-larvae return to the streams and occur at the mouths of streams and rivers during rainy seasons, most abundantly on the day after the full moon. They then migrate back to the estuaries to metamorphose before moving upstream into fresh waters en masse.


The specific name lagocephalus is the Greek lagos (= hare) and kephale (= head), in reference to the short rounded snout and upper jaw, that resembles the nose of a rabbit.

Species Citation

Gobius lagocephalus  Pallas, 1770. Spicilegia Zoologica. 1 Fasc. 8: 14, pl. 2(6, 7). Type locality: Réunion, western Mascarenes, southwestern Indian Ocean (neotype).


Gomon, M.F. & Bray, D.J. 2021


Atlas of Living Australia

Blue Streamgoby, Sicyopterus lagocephalus (Pallas 1770)


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

Bell, K. 1999. An overview of goby-fry fisheries. Naga, The ICLARM Quarterly 22(4): 30-36.

Berrebi P, Galewski T, Keith P (2006) Sicyopterus “lagocephalus”, a unique widespread taxon confirmed by mtDNA sequences. Molecular Phylogenetics and Evolution 40: 903–904

Boseto, D. 2012. Sicyopterus lagocephalus. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. . Downloaded on 06 October 2013.

Donaldson, J. A., Ebner, B. C. & Fulton, C. J. 2013. Flow velocity underpins microhabitat selectivity in amphidromous gobies of the Australian Wet Tropics. Freshwater Biology 58: 1038–1051.

Ebner, B.C., Thuesen, P.A., Larson, H. & Keith, P. 2012. A review of distribution, field observations and precautionary conservation requirements for sicydiine gobies in Australia. Cybium 35: 397–414

Ellien C., Valade P., Bosmans J., Taillebois L., Teichert, N. & Keith P. 2012. Influence of a salinity gradient on the acquisition of marine characters for Sicyopterus lagocephalus larvae. Cybium 35(4): 381-390.

Keith, P. 2003. Biology and ecology of amphidromous Gobiidae of the Indo-Pacific and Caribbean regions. Journal of Fish Biology 63: 831-847.

Keith, P., Galewski, T., Cattaneo-Berrebi, G,. Hoareau, T. & Berrebi P. 2005. Ubiquity of Sicyopterus lagocephalus (Teleostei: Gobioidei) and phylogeography of the genus Sicyopterus in the Indo-Pacific area from mitochondrial cytochrome b gene. Molecular Phylogenetics and Evolution 37: 721-732. Abstract

Keith P, Hoareau T, Lord C, Ah-Yane O, Gimmoneau G, et al. 2008. Characterisation of post-larvae to juvenile stages, metamorphosis, and recruitment of an amphidromous goby, Sicyopterus lagocephalus (Pallas, 1767) (Teleostei: Gobiidae: Sicydiinae). Marine & Freshwater Research 59: 876–889.

Keith, P., Lord, C., Lorion, J., Watanabe, S., Tsukamoto, K., Couloux, A.& Dettai, A. 2011. Phylogeny and biogeography of Sicydiinae (Teleostei: Gobiidae) inferred from mitochondrial and nuclear genes. Marine Biology 158: 311-326. Abstract

Keith, P., Lord, C., Lorion, J., Watanabe, S., Tsukamoto, K., Couloux, A.& Dettai, A. 2011. Erratum to: Phylogeny and biogeography of Sicydiinae (Teleostei: Gobiidae) inferred from mitochondrial and nuclear genes. Marine Biology 158: 327. doi:10.1007/s00227-010-1603-5

Keith, P., Marquet, G., Valade, P., Bosc, P. & Vigneux, E. 2006. Atlas des poissons et des crustacés d'eau douce des Comores, Mascareignes et Seychelles Muséum national d'Histoire naturelle, Paris. Publications scientifiques du Muséum National d'Histoire Naturelle, Paris.

Kottelat, M. 2007. Nomenclatural status and identity of Gobius lagocephalus (Teleostei: Gobiidae). Molecular Phylogenetics and Evolution 43(2): 693-695.

Lord, C., Bellec, L., Dettaï, A., Bonillo, C. & Keith, P. 2019. Does your lip stick? Evolutionary aspects of the mouth morphology of the Indo‐Pacific clinging goby of the Sicyopterus genus (Teleostei: Gobioidei: Sicydiinae) based on mitogenome phylogeny. Journal of Zoological Systematics and Evolutionary Research 57: 910– 925.

Lord, C., Brun, C., Hautecœur, M. & Keith, P. 2010. Insights on endemism: comparison of the duration of the marine larval phase estimated by otolith microstructural analysis of three amphidromous Sicyopterus species (Gobioidei: Sicydiinae) from Vanuatu and New Caledonia. Ecology of Freshwater Fish 19(1): 26-38.

Maie, T., Schoenfuss, H. L., & Blob, R. W. 2012. Performance and scaling of a novel locomotor structure: adhesive capacity of climbing gobiid fishes. The Journal of Experimental Biology 215(22): 3925–3936. PDF Open access

Marquet, G., Keith, P. & Vigneux, E. 2003. Atlas des poissons et des crustacés d'eau douce de Nouvelle-Calédonie. Patrimoines naturels (M.N.H.N./S.P.N.) 58: 1-282.

Pallas, P.S. 1770. Spicilegia Zoologica, quibus novae imprimus et obscurae animalium species iconibus, descriptionibus atque commentariis illustrantur. Berlin Tom. 1 Fasc. 8 54 pp. 5 pls

Sparks JS, Smith WL. 2006. Sicyopterus lagocephalus: Widespread species, species complex, or neither? A critique on the use of molecular data for species identification. Molecular Phylogenetics and Evolution 40(3) : 900-902.

Thuesen, P.A., Ebner, B.C., Larson, H.K., Keith, P., Silcock, R.M., Prince, J. & Russell, D.J. 2011. Amphidromy links a newly documented fish community of continental Australian streams, to oceanic islands of the west Pacific. PLoS ONE  6(10): e26685 (11 pages) PDF Open access

Valade P, Lord C, Grondin H, Bosc P, Taillebois L, Iida M, Tsukamoto K, Keith P (2009) Early life history and description of larval stages of an amphidromous goby, Sicyopterus lagocephalus (Pallas, 1767) (Teleostei: Gobiidae: Sicydiinae). Cybium 33: 309–319.

Watson, R.E., Marquet, G. & Pollabauer, C. 2000. New Caledonia fish species of the genus Sicyopterus (Teleostei: Gobioidei: Sicydiinae). aqua, Journal of Ichthyology and Aquatic Biology 4(1): 5-34.

Quick Facts

CAAB Code:37428335


Conservation:IUCN Least Concern

Fishing:Aquarium fish

Habitat:Freshwater streams, marine larvae

Max Size:12 cm SL

Species Image Gallery

Species Maps

CAAB distribution map