Poreless Gudgeon, Oxyeleotris nullipora Roberts 1978

Other Names: Dwarf Gudgeon, Jardine Gudgeon

Summary:

A brown gudgeon, darker above becoming whitish on belly and underside of head, often with a series of dark brown chevron-shaped markings often on sides, a pair of vertical dark brown blotches at upper and lower base of caudal fin, and a dark brown spot with a white centre above the pectoral-fin base.

Cite this page as:

Martin F. Gomon, Oxyeleotris nullipora in Fishes of Australia, accessed 14 Oct 2024, https://fishesofaustralia.net.au/home/species/1177

Poreless Gudgeon, Oxyeleotris nullipora Roberts 1978

More Info

Distribution	Known in northern Australia from Darwin (131°E, to Arnhem Land (134°E), NT and in western rivers of Cape York, QLD (11°S to 13°S); also occurs in New Guinea; benthic, inhabiting freshwater in backwaters of rivers, small creeks, swamps, and lily lagoons, usually among thick aquatic vegetation over soft mud bottoms; in clear to turbid water, with acidic pH.
Features	Meristic features: Dorsal fin VI + I, 10-11; Anal fin I, 7-10; Caudal fin (branched rays) 13; Pectoral fin 11-12; Transverse Scales 19-20; Gill rakers (lower limb) 8-9; Vertebrae 26-28. Body elongate, cylindrical, depth 4.5-5.5 in SL. Head depressed, profile straight, 2.75-3.2 in SL. Snout slightly shorter than eye to as long as eye, tip before lower margin of eye. Anterior nostril in short tube. Eye diameter 4.5-6.0 in head length; interorbital 1-2 eye diameters. Lower jaw protruding, mouth oblique, reaching to below anterior part or middle of eye; jaw teeth in several rows, upper jaw with outer row slightly enlarged; outer row in lower jaw at front and a few teeth laterally of inner row enlarged. Head pores absent. Mucous canals radiating under eye; two canals longitudinally on cheek. Scales on body ctenoid, cycloid on nape, breast and belly; longitudinal series 30-38; horizontal scale rows 11-12; cycloid scales on head scaled above from dorsal fin to in front of eyes, on cheek and opercle; predorsal scales 19-23. Two dorsal fins, first dorsal fin much lower than body depth; height of second dorsal about 0.67 body depth; caudal fin rounded. Pectoral fin rounded, as long as head without snout. Pelvic fins separate, slightly shorter than pectorals.
Size	To around 4 cm SL.
Colour	Brown, darker on back, becoming whitish on belly and underside of head; series of dark brown chevron-shaped markings often on sides; pair of vertical dark brown blotches at upper and lower base of caudal fin; dark brown spot with white centre above base of pectoral fin; 3 dusky brown bands radiating posteriorly from eye; fins mainly clear or whitish, dorsal fins with small brown spots forming stripes and caudal with similar spots forming wavy, transverse bands.
Feeding	Carnivore - likely to feed on small crustaceans and aquatic insects.
Biology	Oviparous, benthic spawners. Females deposit about 30 adhesive eggs (~ 2mm diam) onto the underside of overhanging rocks or crevices. The male parent guards and fans the eggs until the larvae hatch after about 8 days.
Species Citation	Oxyeleotris nullipora Roberts, 1978, Smithson. Contrib. Zool. 281: 67, fig. 38c. Type locality: lower Kanggu River, tributary of Fly River, Papua New Guinea.
Author	Martin F. Gomon

Poreless Gudgeon, Oxyeleotris nullipora Roberts 1978

References

Allen, G.R. & Hoese, D.F. (1980). A collection of fishes from the Jardine River, Cape York Peninsula, Australia. J. R. Soc. West. Aust. 63(2): 53–61 figs 1–2 (as Oxyeleotris sp. B).

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

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.

Roberts, T.R. (1978). An ichthyological survey of the Fly River in Papua New Guinea with descriptions of new species. Smithson. Contrib. Zool. 281: 1–72 figs 1–39