Roman-nose Goby, Awaous acritosus Watson 1994


Other Names: Roman Nose Goby

A Roman-nose Goby, Awaous acritosus. Source: Queensland Department of Science, Information Technology, Innovation and the Arts. License: All rights reserved

Summary:

A large pale brownish goby with irregular dark blotches and lines on the head and body, a series of blackish blotches along the midside, and a fine dark line from the eye to the rear of the upper lip. The species has large lips, and a distinctly sloping snout - hence the common name.

In a recent study, Huey et al. (2014) found that the species is amphidromous - meaning that the larvae may be washed downstream into estuaries or the sea where they develop before migrating back to freshwater as juveniles.

The Roman-nose Goby has been misidentified as Awaous crassilabrus, a species that does not occur in Australia.


Cite this page as:
Martin F. Gomon & Dianne J. Bray, Awaous acritosus in Fishes of Australia, accessed 28 Jan 2020, http://136.154.202.208/home/species/1310

Roman-nose Goby, Awaous acritosus Watson 1994

More Info


Distribution

Found in northeastern Australia, from Cape York to the wet tropics and south to the Herbert River, Queensland; also in southern New Guinea.

Adults inhabit tropical freshwater streams above the tidal influence, while the larvae may be washed downstream to estuaries or the sea. The species is usually found in clear, or occasionally turbid waters, with gravelly, sandy and muddy bottoms near aquatic vegetation.

Features

Meristic features: Dorsal fin VI; I, 10; Anal fin I, 10; Pectoral fin 16-17; Pelvic fin I, 5; Transverse scales 14-17; Gill rakers 2-4 + 1 + 4-5.
Body elongate, cylindrical anteriorly, compressed posteriorly, depth 4.5-6.5 in SL. Head obtuse, length 3.3-3.8 in SL, dorsal profile convex. Eye 4.5 in head length, above level of snout tip. Snout much longer than eye diameter in adults. Lips thick, distinct groove between upper lip and snout; upper jaw prominent, reaching to or almost to front of eye; teeth in several rows, outer row in upper jaw slightly enlarged, not in lower jaw; males usually with slightly longer upper jaw and more teeth in both jaws. Gill openings wide, not restricted; 2-4 elongate papillae on shoulder girdle.
Scales laterally on sides ctenoid; scales posterior to hypural base cycloid, ctenoid or both; small cycloid scales often along bases of second dorsal and anal fins; predorsal fully scaled, midline scales 18-24, cycloid; upper opercle with 0-8 cycloid scales; cheek almost always naked; pectoral base usually naked in young and with cycloid scales in adults; breast with thin cycloid scales, often slightly embedded; belly with cycloid scales usually close to pelvic fin base. Lateral line absent; scales in longitudinal series 56-62.
Two dorsal fins, first with same height as second fin, spines not filamentous; second dorsal of moderate length and uniform height. Anal fin similar to and opposite second dorsal fin. Pectoral fins of moderate length. Pelvic fins united into complete disc, not reaching anus.

Size

To around 18 cm SL

Colour

Cream with 4-6 large blackish spots mid-laterally on sides ending with spot on caudal base, irregular dusky streaks and spots between spots, 4-7 dusky spots usually forming saddles on back; head with slightly bluish cast, 2 dusky streaks from anterior edge of orbit to upper jaw and sometimes spots or streaks on cheek and upper opercle. Fins whitish, dorsal fins with rows of blackish marks mostly on spines and rays, not extending onto membrane; dorsal two-thirds of caudal fin with blackish marks, most prominent on rays, forming vertical bands, lower third of fin sometimes dusky; anal fin translucent basally and whitish distally; pectoral fin translucent with large black spot or bar dorsally on base; pelvic disk translucent.

Feeding

Feeds mostly on algae, but also ingests large amounts of sand thereby unintentionally consuming detritus and animal material.

Biology

Little is known of the biology of this species. Females deposit adhesive eggs onto hard surfaces such as rocks or logs, where they are guarded by the parents until the larvae hatch.

The species is amphidromous, and the larvae are washed downstream after they hatch. In steeper catchments, the larvae may be carried into estuaries or out into the sea. After a period of development, juveniles migrate back upstream.

Similar Species

Long confused with Awaous crassilbarus, a species not found in Australia.

Etymology

The species name acritosus is from the Greek akritos, meaning 'confused', in reference to incorrect identity of this species for more than 125 years.

Species Citation

Awaous acritosus Watson, 1994,  Ichthyol. Explor. Freshw. 5(4): 372, fig. 1. Type locality: Brown River, Papua New Guinea.

Author

Martin F. Gomon & Dianne J. Bray

Roman-nose Goby, Awaous acritosus Watson 1994

References


Allen, G.R. 1989. Freshwater Fishes of Australia.  Neptune, New Jersey : T.F.H. Publications 240 pp. pls 1–63 (p.202, as A. crassilabris).

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

Boseto, D. 2012. Awaous acritosus. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 19 April 2013.

Huey, J.A., Crook, D.A., Macdonald, J.I., Schmidt, D.J., Marshall, J. C., Balcombe, S. R., Woods, R.J.& Hughes, J. M. 2014. Is variable connectivity among populations of a continental gobiid fish driven by local adaptation or passive dispersal? Freshwater Biology doi: 10.1111/fwb.12373 Abstract

Larson, H.K. & Murdy, E.O. 2001. Eleotridae, Gobiidae. pp. 3574-3604 in Carpenter, K.E. & Niem, T.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 6 pp. 3381-4218.

Merrick, J.R. & Schmida, G.E. (1984). Australian Freshwater Fishes Biology and Management.  Sydney : J.R. Merrick 409 pp. figs 280 col. figs (p. 308, as A. crassilabris).

Pusey, B.J., Kennard, M.J. & Arthington, A.H. 2004. Freshwater Fishes of North-eastern Australia. Collingwood, Victoria : CSIRO Publishing 684 pp.

Unmack, P.J. 2001. Biogeography of Australian freshwater fishes. Journal of Biogeography 28: 1053-1089.

Watson, R.E. 1994. Awaous (Awaous) acritosus, a new species of freshwater goby from southern New Guinea and northeastern Australia (Teleostei: Gobiidae). Ichthyological Exploration of Freshwaters 5(4): 371-376.

Quick Facts


CAAB Code:37428061

Biology:Amphidromous

Conservation:IUCN Least Concern

Habitat:Coastal streams

Max Size:18 cm SL

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