Wednesday, 7 March 2012

New species of Parrotfish from the East Atlantic.

Parrotfish are a form of Wrasse with highly specialized dentition, in which the teeth are tightly packed together to form a sort of beak, used to break off chunks of coral, on which the fish feed. They are brightly coloured and found throughout the tropics, adding to their parrot-like appearance. Parrotfish are sequential hermaphrodites, starting out as females then turning into males later; the timing and trigger for this change varies from species to species.

In a paper published in the journal Zootaxa on 6 January 2012, Luiz Rocha of the Ichthyology Section at the California Academy of Sciences, Alberto Brito of the Departamento de Biología Animal (Ciencias Marinas) at the Facultad de Biología at Universidad de La Laguna and Ross Robertson of the Smithsonian Tropical Research Institute in Balboa, Panamá report the discovery of a new species of Parrotfish from the Eastern Atlantic.

The new fish was first discovered in Cape Verde, where it was noticed that fish previously thought to belong to the same species as Parrotfish in the Caribbean had different colouration. Subsequent genetic studies proved these to be a separate species of fish. This has been named as Sparisoma choati, the West African Parrotfish, or Choat's Parrotfish (in honor of J. Howard Choat, an expert on Parrotfish at James Cook University).

Male Sparisoma choati. From Rocha et al. (2012).

Female Sparisoma choati are a grayish brown to grayish red, paler on the chin and belly, with scattered reddish brown scales on the flanks giving a mottled appearance. The edges of the scales are darker, further contributing to this mottled appearance. Fins are grayish or whitish red, except the dorsal fin which is translucent red, with a black or dark red spot. The eyes are orange.

Female Sparisoma choati. From Rocha et al. (2012).

The male Sparisoma choati are more colourful, with a reddish brown head and forepart of the body, pale underparts, grey cheeks, and grey-green hind-parts, bright green on the belly. The scales are edged in bright green, the caudal (tail) fins are grey, the anal (rear) fins blue, the dorsal fin reddish brown at the front and gray at the back. The pectoral (front) fins are brownish red with a green base and a black spot.

As well as in Cape Verde the fish have been found in São Tomé, and along the African coast from Senegal to Angola.

The distribution of Sparisoma choati (stars), and the related species S. rubripinne (squares) and S. axillare (circles). From Rocha et al. (2012).

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