Species Profile: Melanotaenia rubrivittata

Species Photo by: Gary Lange

Description:   Males head greyish dorsally, silvery blue on cheek and operculum; brilliant neon blue on upper two-thirds of body with five red stripes; ventral portion of head and body silvery white to blue with slight pinkish hue; first dorsal fin blue; second dorsal fin blue with red basal stripe and broad red zone encompassing outer margin and posterior portion of fin; anal fin bluish with red basal stripe and red outer margin; caudal fin red, grading to bluish or translucent along posterior margin; pelvic fins bluish to translucent with red anterior margin and reddish posterior tip; pectoral fins translucent. Nuptial males are capable of "switching on" a golden-orange mid-dorsal stripe, extending from the dorsal-fin origin to the snout tip. Colour pattern of freshly captured females generally similar to that of males except overall pattern is much duller and lacks brilliant red markings on fins; second dorsal and anal fins with blue outer margin. Melanotaenia rubrivittata is most similar in appearance to Melanotaenia praecox from the Mamberamo River system, lying approximately 100 km to the east. The two species share a number of similarities including a neon-blue ground colour, brilliant red markings on the median fins, relatively small maximum size (less than about 50 mm SL), overlapping counts for dorsal rays, anal rays, pectoral rays, predorsal scales, and cheek scales, and most morphometric proportions. Genetic results reveal the two species are clearly separable. In addition, M. praecox lacks the characteristic red body stripes of male M. rubrivittata. The males of M. praecox also tend to be deeper bodied than males of M. rubrivittata. There is also a slight difference in snout length with M. praecox generally having a shorter snout than M. rubrivittata. Lastly, M. praecox has fewer lateral scales (usually 29-30 versus 32-33) and frequently has 11 transverse scales (always 10 in M. rubrivittata).

Category:   Rainbowfish

Global Region:   Oceania

Distribution:   Wapoga River system