Daintree Rainbowfish, Cairnsichthys bitaeniatus Allen, Hammer & Raadik 2018


A pair of Daintree Rainbowfish, Cairnsichthys bitaeniatus, from Little Cooper Creek, Queensland, photographed in an aquarium (male top, female below). Source: Michael Hammer / NTM. License: All rights reserved

Summary:
A slender, compressed rainbowfish with a short broad rectangular patch on the upper part of the gill cover above a yellow spot, a yellow patch behind the pectoral-fin base with a bluish area below, a black midlateral stripe, a second indistinct black stripe along the lower side, a prominent black spot on the pectoral-fin base, and bright yellowish fins in adult males.

Cite this page as:
Bray, D.J. 2018, Cairnsichthys bitaeniatus in Fishes of Australia, accessed 18 Nov 2018, http://fishesofaustralia.net.au/Home/species/5431

Daintree Rainbowfish, Cairnsichthys bitaeniatus Allen, Hammer & Raadik 2018

More Info


Distribution

Endemic to the Cooper Creek and nearby Hutchinson Creek systems of the Daintree region, north-eastern Queensland.
Inhabits small clear somewhat shaded rainforest streams flowing over mixed rock, sand, gravel and log debris. Individuals swim near the surface to midwater depths, often in deeper pools in areas of high flow - sometimes schooling with blue-eyes and other rainbowfishes. 

Features

Dorsal fin V–VII + 12–15; Anal fin I, 19–23 (spine slender, flexible); Pectoral fin 11–13; Pelvic fin I, 5; Caudal fin (branched rays) 15; Procurrent caudal rays 7–9 + 8–10; Lateral scales 38–40, including 3.5–5 (usually 4) from end of adpressed pectoral fin to vertical from with dorsal fin origin; Transverse scales 11; Predorsal scales 18–22; Cheek scales 6–9; Circumpeduncular scales 12; Gill rakers on first arch 11–16; Vertebrae 37–40.
Head length 3.7–4.2 in SL; body depth 3.8–5.3 in SL; greatest width of body 2.1–2.8 in HL; snout length 2.9–3.6 in HL; eye diameter 2.5–3.2 in HL; bony interorbital width 2.5 (2.3–2.8) in HL; depth of caudal peduncle 2.8 (2.2–2.9) in HL; length of caudal peduncle 1.7 (1.4–1.8) in HL.
Body scales relatively large, cycloid,  arranged in regular horizontal rows; predorsal scales extending forward to about rear edge of interorbital space.

Feeding

Presumably feeds mostly on terrestrial invertebrates taken from the surface.

Biology

Although little is known of the biology of this species, like the Cairns Rainbowfish, it presumably breeds from August to October, with females depositing batches of eggs amongst root masses.

Similar Species

Differs from the Cairns Rainbowfish, Cairnsichthys rhombosomoides, in having a more robust black stripe across the upper operculum, a more intense black spot on the pectoral fin base, a pronounced yellow patch on the anteroventral body, and usually a more conspicuous second dark stripe on the lower body (vs. the second stripe absent or diffuse in C. rhombosomoides. Adult males also have yellow fins (vs. orange-reddish in C. rhombosomoides). The Daintree Rainbowfish also has smaller scales, more vertebrae and a shorter dorsal-fin base than the Cairns Rainbowfish.

Etymology

The specific name bitaeniatus is from Latin (double ribbon) in reference to the two dark stripes on the side, in contrast to C. rhombosomoides which generally has a more inconspicuous ventral stripe or it is absent.

Species Citation

Allen, Hammer & Raadik 2018, in Hammer et al. Zootaxa 4413 (2): 279, figs 4–8. Type locality: Little Cooper Creek (16° 10.20'S, 145° 24.84'E), north Queensland.

Author

Bray, D.J. 2018

Resources


Daintree Rainbowfish, Cairnsichthys bitaeniatus Allen, Hammer & Raadik 2018

References


Hammer, M.P., Allen, G.R., Martin, K.C., Adams, M., Ebner, B.C., Raadik, T.A. & Unmack, P.J. 2018. Revision of the Australian Wet Tropics endemic rainbowfish genus Cairnsichthys (Atheriniformes: Melanotaeniidae), with description of a new species. Zootaxa 4413 (2): 271–294 https://doi.org/10.11646/zootaxa.4413.2.3 Abstract

Martin, K.C. & Barclay, S. 2013. New distribution records for the Cairns rainbowfish Cairnsichthys rhombosomoides (Melanotaeniidae): implications for conservation of a restricted northern population. aqua, lnternational Journal of Ichthyology 19: 155–164 (in part as Cairnsichthys rhombosomoides).

Quick Facts


Habitat:Freshwater streams

Max Size:6 cm SL

Native:Endemic

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