Sharpnose Grunter, Syncomistes butleri Vari 1978

Other Names: Butler's Grunter, Sharp-nose Grunter

Sharpnose Grunter, Syncomistes butleri. Source: Dave Wilson. License: All rights reserved

A dark grunter with scale edges more heavily pigmented, and lighter margins on the dorsal fins, especially on the soft dorsal fin. Juveniles have 5-6 stripes along the side - the median stripe is distinctly wider than the others.

Video of Butler's Grunter in the South Alligator River catchment, Kakadu National Park, Northern Territory - along with Sooty Grunter (Hephaestus fuliginosus), and the Banded or Black-striped Grunter (Amniataba percoides). Butler's Grunter, which has a sharper snout than the Sooty Grunter, is the most common fish in this video.

Cite this page as:
Gomon, M.F. & Bray, D.J. 2020, Syncomistes butleri in Fishes of Australia, accessed 24 May 2024,

Sharpnose Grunter, Syncomistes butleri Vari 1978

More Info


Endemic to the Northern Territory, from the Adelaide River to the Goyder River - the only species of Syncomistes known from this area. Inhabits deeper sections of slow-flowing creeks and rivers, and billabongs - in clear and turbid waters, over muddy to rocky substrates, often in areas with abundant algal growth. Adults form shoals around snags, while juveniles mostly occur in riffle habitats.


S. butleri differs from all other species of Syncomistes in having the following combination of characters: lower jaw rounded anteriorly, making a ‘U-shape’ when viewed from below, in juveniles and adults; mouth slightly oblique; teeth relatively broad and large, flat, asymmetric, margins convex posteriorly and straight to slightly concave anteriorly, widest point closest to mid-point of tooth, apical region tapered to slight point; body often with 5–6 slightly wavy brown stripes running horizontally along sides; usually ≥ 11 gill rakers on the upper arch and ≥ 30 in total; usually < 6.0 teeth per mm of jaw length.


To 28 cm, commonly 15-20 cm SL


Adults uniformly dark, with darker scale margins, pigmentation increasing dorsally. Top of head down to level of snout, top of lower lip and suborbital region dark; opercle and subopercle dark below opercular spines. Dorsal fin dark, with paler edges, especially in soft dorsal; caudal, anal, and pelvic fins dark, first two fins sometimes with pale margins. Pectoral fins colourless.
Small juveniles with 5-6 longitudinal body stripes, fourth about twice width of others. Top of head mostly pale; horizontal stripe below eye to opercle; opercle and subopercle with dark blotch extending ventrally from opercular spine. Dorsal fin with dusky membranes anteriorly and spots at base of rays. Caudal fin with vertical bar at base. Membranes of spinous anal dusky. Soft anal with dark basal blotch. Membranes of pelvics dark. Pectorals colorless.
Intermediate fish much darker overall; fourth body stripe still prominent, but third, fifth, and sixth less so. Upper two and suborbital stripe very faint or absent. Spinous dorsal much darker. Anal blotch and pelvic coloration more pronounced.


Herbivore/detritivore with a highly modified gut. The teeth and jaws are adapted to grazing on filamentous algae-covered rocks. The species also consumes some detritus and invertebrates.


Individuals are sexually mature at 120–140 mm. Breeding occurs during the wet season, and females spawn a large number of relatively large (~3mm) non-aadhesive eggs. The male parent guards and fans the eggs until the larvae hatch.


The Sharpnose Grunter is known only from the Adelaide River to the Goyder River, Northern Territory. Records from the Kimberley region of Western Australia, to the Finnis River, Northern Territory are based on Syncomistes bonapartensis. The paratypes of Syncomistes butleri from the Daly, Victoria, Ord, and Drysdale rivers, are now referable to S. bonapartensis

Similar Species

Differs from other species of Syncomistes (except the very similar S. bonapartensis) in having a terminal mouth, a wide, rounded U-shaped jaw when viewed from below, and a thick, fleshy lip fold on the upper and lower lip, a deeper body at the dorsal fin origin 38 (34.4–46.1) % SL and at the anal fin origin 32.9 (27.5–40.2) % SL, and a distinctively steep ventral profile that is straight or concave in adults and slightly convex in juveniles.

S. butleri has fewer horizontal stripes (when present) than S. bonapartensis (5-6 vs. 7-8 stripes). This character is particularly useful in distinguishing juvenile specimens, as stripes are most often present


The species is named butleri in honour of Mr. William Henry "Harry" Butler, a popular naturalist and member of the American Museum of Natural History–Australian Expedition of 1969.

Species Citation

Syncomistes butleri Vari, 1978, Bull. Amer. Mus. Nat. Hist. 159(5): 311. Type locality: Lilly (Barramundie) Lagoon, near Barramundie Creek, Northern Territory.


Gomon, M.F. & Bray, D.J. 2020


Atlas of Living Australia

Sharpnose Grunter, Syncomistes butleri Vari 1978


Allen, G.R. 1982. Inland Fishes of Western Australia. Perth : Western Australian Museum 86 pp. 6 figs 20 pls. (in part) 

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

Davis, A.M., Unmack, P.J., Pusey, B.J., Pearson, R.G. & Morgan, D.L. 2013. Ontogenetic development of intestinal length and relationships to diet in an Australasian fish family (Terapontidae). BMC Evolutionary Biology 13: 53, 16 pp. (in part) 

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. (in part) 

Larson, H.K., Williams, R.S. & Hammer, M.P. 2013. An annotated checklist of the fishes of the Northern Territory, Australia. Zootaxa 3696(1): 1-293 (in part)

Shelley, J.J. 2016. Evolution and biogeography of Australian tropical freshwater fishes. PhD Thesis. The University of Melbourne, Melbourne, VIC, 273 pp.

Shelley, J.J., Delaval, A. & Le Feuvre, M.C. 2017. A revision of the grunter genus Syncomistes (Teleostei, Terapontidae, Syncomistes) with descriptions of seven new species from the Kimberley region, northwestern Australia. Zootaxa 4367(1): 1-103

Shelley, J.J., Gomon, M.F. & Le Feuvre, M.C. 2018. Family Terapontidae. pp. 118-158 in Shelley, J.J., Morgan, D.L., Hammer, M.P., Le Feuvre, M.C., Moore, G.I., Gomon, M.F., Allen, M.G. & Saunders, T. (eds) A field guide to the freshwater fishes of the Kimberley. Murdoch University, Murdoch, Western Australia, 262 pp.  

Shelley, J.S., Swearer, S.E., Adams, M., Dempster, T., Le Feuvre, M.C., Hammer, M.P. & Unmack, P.J. 2018. Cryptic biodiversity in the freshwater fishes of the Kimberley endemism hotspot, northwestern Australia, Molecular Phylogenetics and Evolution 127: 843-858,

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

Vari, R. P. (1978) The terapon perches (Percoidei, Teraponidae). A cladistic analysis and taxonomic revision. Bulletin of the American Museum of Natural History 159(5): 175-340 (in part)

Quick Facts

CAAB Code:37321028

Habitat:Freshwater lagoon, streams

Max Size:28 cm SL


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