Dillie Grunter, Syncomistes dilliensis Shelley, Delaval & Le Feuvre 2017


Summary:
A relatively small mostly black to sometimes bluish grunter with no horizontal stripes on the body.

Cite this page as:
Bray, D.J. 2018, Syncomistes dilliensis in Fishes of Australia, accessed 25 Jun 2018, http://fishesofaustralia.net.au/Home/species/5401

Dillie Grunter, Syncomistes dilliensis Shelley, Delaval & Le Feuvre 2017

More Info


Distribution

Endemic to the Isdell, Charnley, and Calder Rivers in The Kimberley region, Western Australia. Adults prefer fast flowing sections of creeks and rivers, although they often occur in deep, slow flowing pools. Inhabits clear waters over rocky substrates, often where algae is abundant. Juveniles occur mostly in riffle habitats.

Features

Syncomistes dilliensis differs from all other species within the genus Syncomistes in having the following combination of characters: lower jaw distinctly pointed when viewed from below, making a ‘V-shape’ in individuals > 65 mm; mouth subterminal; teeth flattened, narrow and short, ‘peg-shaped’ with anterior and posterior edges running straight and parallel from tooth base, tapering slightly at apical region to a rounded point; jaw of adults (> 65 mm) as wide as it is long or slightly longer when viewed from below; dorsal profile straight from dorsal origin to shallow notch on upper jaw; body lacking stripes; ventral profile only slightly convex; head slightly rounded from juveniles through to adults; jaw relatively short usually < 30.0 in HL; 9–11 anal fin rays (usually 10); 17–19 gill rakers on lower arch (usually 18); postorbital length relatively short, usually < 40.0 % HL.

Size

A relatively small species of Syncomistes (recorded up to 132 mm SL, commonly 70–100 mm SL).

Colour

A mostly black or sometimes bluish grunter with no horizontal stripes on the body.

Feeding

Diet primarily consists of filamentous algae scraped off rocks with specially modified teeth.

Biology

Nothing is known about the reproductive biology of this species. 

Similar Species

Broadly similar morphological grouping to Syncomistes versicolor, Syncomistes dilliensis, and S. rastellus based on the presence of a more pronounced, longer notch behind the upper lip, a more pronounced concave dorsal profile between the notch and the dorsal fin, and a squat V-shaped jaw that is wider than it is long. Unique in appearance although, most closely resembles S. rastellus. Syncomistes dilliensis can be distinguished from by having, on average, less dorsal spines 11 (11–12) and greater counts of the following characters: lateral line scales 52 (48–53), scale rows between the lateral line and dorsal 13 (10–14) and pectoral origin 22 (18–23), dorsal sheath scale rows 2, caudal peduncle scales 34 (33–37), and teeth on the lower jaw (relative to jaw length). Differences in morphology include shorter jaw width 28.3 (26.3–32.6) % HL and smaller fin measurements including: dorsal base length 50.4 (48.5–53.2) % SL, dorsal fin length 55.5 (51.8–58.3) % SL, dorsal spine length 11.7 (10.3–13.5) % SL, anal spine length 12.9 (11.2–15.1) % SL, pectoral fin length 19.6 (17.8–21.2) % SL, and pelvic spine length 9.2 (7.8–10.6) % SL. Body colour is variable, although overall colour ranges from olive green / blue in juveniles to black in adults, rather than silver in juveniles and adults (Syncomistes holsworthi), gold in juveniles to black in adults (Syncomistes dilliensis), or olive green to light brown in juveniles and adults (S. rastellus).

Etymology

The specific name dilliensis refers to the type locality, Dillie Gorge, on the Charnley River, Western Australia.

Species Citation

Syncomistes dilliensis Shelley, Delaval & Le Feuvre 2017, Zootaxa 4367(1): 42, Fig. 14. Type locality: Charnley River at Pearson Creek confluence with Charnley River, 16° 12' 39.63'' S, 125° 30' 17.53'' E.

Author

Bray, D.J. 2018

Dillie Grunter, Syncomistes dilliensis Shelley, Delaval & Le Feuvre 2017

References


Shelley, J.J. 2016. Evolution and biogeography of Australian tropical freshwater fishes. PhD Thesis. The University of Melbourne, Melbourne, VIC, 273 pp. (as Syncomistes sp. 3)

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 DOI: http://dx.doi.org/10.11646/zootaxa.4367.1.1  Abstract

Quick Facts


Habitat:Freshwater

Max Size:13.2 cm SL

Native:Endemic

Species Maps

CAAB distribution map