Ornate rainbowfish

Ornate rainbowfish
Rhadinocentrus ornatus Searys Ck male.JPG
male from Searys Creek, southeast Queensland, Australia
Rhadinocentrus ornatus Searys Ck female.JPG
female from Searys Creek, southeast Queensland, Australia
Scientific classification edit
Kingdom:Animalia
Phylum:Chordata
Class:Actinopterygii
Order:Atheriniformes
Family:Melanotaeniidae
Subfamily:Melanotaeniinae
Genus:Rhadinocentrus
Regan, 1914[1]
Species:
R. ornatus
Binomial name
Rhadinocentrus ornatus
Regan, 1914

The ornate rainbowfish (Rhadinocentrus ornatus) is a species of rainbowfish endemic to the coastal regions and sandy offshore islands in southern Queensland and northern New South Wales in eastern Australia. It is the only known member of its genus. It is a popular aquarium fish.

Description

The ornate rainbowfish is a small, slender and rather elongated species of rainbowfish. It has two dorsal fins that are only narrowly separated, and the first dorsal fin is considerably smaller than the second.[2] There are 3 to 5 thin, soft spines in the first dorsal fin while the second dorsal fin has 11–15 segmented rays.[3] This species is highly variable in colour over its range. The body is semi-transparent, and they have two rows of black scales along the middle of their flanks. They have iridescent scales above the lateral line and just below the dorsal fin, and these can be either red or a metallic light blue. The dorsal, anal and caudal fins are normally blue, although are sometimes red, and have black edges.[2] The semi-transparent body may have hues of blue, pink or red with the dark edges of the scales creating a network-like pattern and the two mid-lateral dark stripes described above. They have neon blue iridescent patches on their backs and on the nape. An example of the geographic variation in colour is that a golden-yellow morph is found in the Key Hole Lakes system on Stradbroke Island,[3] while another population on that island had distinctive black stripes on the flanks which created an overall dark colouration.[2] The males of this species grows to a length of 6 centimetres (2.4 in) Standard Length, the females to 3.5 centimetres (1.4 in).[4]