Crimsonspotted Rainbowfish, Melanotaenia duboulayi (Castelnau 1878)

Other Names: Crimson-spotted Rainbowfish, Doublay's Rainbowfish

Summary:

A popular aquarium fish with a highly variable colour pattern depending on locality. Males and females are markedly sexually dimorphic.

Identifying features:
Body olive-brown above, silvery to greenish-blue on sides and white below - becoming yellowish-orange towards rear of body;
Sides with a darkish midlateral stripe and thin reddish stripes;
Gill cover with a reddish spot.

Adult males have a deeper body and are more brightly coloured than females, especially when breeding. Males often have red spots on the caudal, dorsal and anal fins, and develop dark fin margins when breeding.

Video of Crimsonspotted Rainbowfish (Snapper Creek variety)

Cite this page as:

Martin F. Gomon & Dianne J. Bray, Melanotaenia duboulayi in Fishes of Australia, accessed 18 May 2022, https://fishesofaustralia.net.au/home/species/2106

Crimsonspotted Rainbowfish, Melanotaenia duboulayi (Castelnau 1878)

More Info

Distribution	Endemic to freshwaters of eastern Australia, from Mary River, Qld to Macleay River, NSW. Crimsonspotted Rainbowfish inhabit a range of freshwater environments environments including rivers, creeks, drains, ponds, dune lakes and reservoirs in sandy coastal areas and inland forest habitats.
Features	Meristic features: Dorsal-fin rays: V-VIII; I, 8-13 Anal-fin rays: I, 15-21 Pectoral-fin rays: 12-15 Caudal-fin rays: 15-17 Gill rakers: 11-12 Vertebrae: 27-32 Gill rakers: 11-12 Body relatively elongate, slender, laterally compressed, becoming deeper with age; males with deeper body; mouth oblique, extends back to almost below anterior margin of eye; upper jaw protruding; jaw teeth conical to canine-like in several rows extending outside mouth; teeth present on vomer and palatines; head moderately sized, eye relatively large; lateral line absent. Scales large, extending to cheek; vertical scale rows 33-36; horizontal scale rows 11-13. Two separate dorsal fins; origin of first dorsal between origins of pelvic and anal fins; origin of 2nd dorsal fin behind origin of anal fin; dorsal fins separated by a small gap; anal fin long-based; caudal fin slightly forked; males with higher first dorsal and pointed tips of anal and dorsal fins, rounded in females.
Size	To 11cm SL, commonly to 8cm
Colour	Males more brightly coloured than females, especially when breeding; colour patterns vary with locality; dorsal surface generally olive brown, sides silvery to greenish blue, ventral surface white, yellow orange toward tail; thin reddish stripe between each horizontal scale row; usually with a red spot on upper gill cover and a diffuse black midlateral stripe; fins clear in juveniles and females; males often with red spots on caudal, dorsal and anal fins.
Feeding	Omnivorous feeding on terrestrial insects, aquatic insects, algae, charaphytes, macrophytes, micro and macro crustaceans, fish eggs, terrestrial vegetation and molluscs.
Biology	Entire lifecycle is completed in freshwater; sexually mature at 10-12 months; spawns from late winter to summer with peak spawning activity in spring and summer; spawning is likely to occur in beds of aquatic macrophytes and submerged vegetation where eggs are deposited within 10cm of the water surface. Eggs are relatively large, on average around 0.93-1.41 mm diameter. Eggs are demersal with adhesive filaments. Larvae hatch after 5-10 days at 3.7-4.2 mm TL.
Remarks
Species Citation	Atherinichthys duboulayi Castelnau, 1878, Proc. Linn. Soc. N.S.W. (1)3(2): 143. Type locality: Richmond River, NSW.
Author	Martin F. Gomon & Dianne J. Bray
Resources	Junior synonyms: Aristeus lineatus Macleay, 1881 Aristeus perporosus De Vis, 1884

Crimsonspotted Rainbowfish, Melanotaenia duboulayi (Castelnau 1878)

References

Allen, G.R. 1989. Freshwater Fishes of Australia. Neptune, New Jersey : T.F.H. Publications 240 pp., 63 pls.

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

Caller, G. & Brown, C. 2013. Evolutionary Responses to invasion: cane toad sympatric fish show enhanced avoidance learning. PLoS ONE 8(1): e54909. doi:10.1371/journal.pone.0054909

Castelnau, F.L. de 1878. On some new Australian (chiefly) freshwater fishes. Proceedings of the Linnean Society of New South Wales 1 3(2): 140-144 (originally described as Atherinichthys duboulayi)

Crowley, L.E.L.M., Ivantsoff, W. & Allen, G.R. 1986. Taxonomic position of two crimson-spotted rainbowfish, Melanotaenia duboulayi and Melanotaenia fluviatilis (Pisces: Melanotaeniidae), from Eastern Australia, with special reference to their early life-history stages. Australian Journal of Marine and Freshwater Research 37: 385-398 figs 1-6

Leggett, R. & Merrick, J.R. 1987. Australian Native Fishes for Aquariums. Artarmon : J.R. Merrick Publications 241 pp. 142 figs.

Warburton, K. & Madden, C. 2003. Behavioural responses of two native Australian fish species (Melanotaenia duboulayi and Pseudomugil signifer) to introduced poeciliids (Gambusia holbrooki and Xiphophorus helleri) in controlled conditions. Proceedings of The Linnean Society of New South Wales, 124 : 115-123.