Description of a new species of damselfish (Pomacentridae: Chromis) from Rapa Island, French Polynesia
David Lecchini and Jeffrey T. Williams
aqua, International Journal of Ichthyology, pp. 97-102, Volume 8, Issue 3 – June 2004
A new species of pomacentrid fish recently discovered at Rapa Island, Austral Archipelago (French Polynesia), is described. Specimens were collected during a collaborative marine biodiversity survey of Rapa from October to December 2002. Chromis planesi is described from six specimens, 93.6-101.8 mm SL, captured on the outer reef slope at depths of 50 to 54 m. The new species is distinguished from most described species of Chromis by the following combination of characters: dorsal rays XIV,12-13; anal rays II,12-13; pectoral rays 20; tubed lateral line scales 17; total gill rakers 27-30; axil of pectoral fin black; eye-sized bluish white spot (fades and darkens rapidly after death) on body at bases of posteriormost 6 to 8 segmented dorsal rays. Only four species of Chromis (C. fumea, C. notata, C. verater, and C. struhsakeri) have overlapping counts, a black pectoral axil, and the white spot dorsoposteriorly on body as described above for C. planesi. Chromis planesi is easily distinguished from all four of these species by its distinctive colour pattern: yellowish body with nine stripes, each composed of a series of small blue dots, extending from the gill opening to the caudal fin base; pectoral and caudal fins yellow; and pelvic and anal fins dark brown to black. Among the Chromis species with 14 dorsal spines, the colour pattern of C. planesi is most similar to the those of C. meridiana and C. struhsakeri. Chromis meridiana lacks the blue stripes on the body and has a more slender body (body depth (BD) 2.1-2.3 in standard length (SL) versus BD 1.9-2.1 in SL for C. planesi). Chromis struhsakeri differs in lacking blue stripes, lacking yellow fins, having the white spot extending anteriorly from the top of the caudal peduncle only to about the base of the last dorsal segmented ray, and having a deeper body (BD 1.8-1.9 in SL). This distinctive new species is known only from seven specimens (one sacrificed for genetic sampling) collected on the deep outer reef at Rapa Island.
Allen, G. R. 1991. Damselfishes of the World. Mergus, Melle, Germany, 271 pp.
Allen, G. R. & J. E. Wright. 2003. Description of a new species of damselfish (Pomacentridae: Pomacentrus) from Rodrigues Island, Indian Ocean. aqua, 7: 133-138.
Galzin, R., Lecchini, D., Planes, S. & J. T. Williams (in preparation for Cybium). Report on the fishes of Rapa Island, French Polynesia.
Mermet, G. 1986. Rapa. Direction des centres d’expérimentations nucléaires, Service mixte de contrôle biologique, France, 236 pp.
Nichols, J. T. 1923. Two new fishes from the Pacific. American Museum Novitates, 94: 1-3.
Randall, J. E. & H. Sinoto. 1978. Rapan Fish Names. Occasional Papers of the Bernice P. Bishop Museum, 24: 291-306.
Randall, J. E., Smith, C. L. & M. N. Feinberg. 1990. Report on fish collections from Rapa, French Polynesia. American Museum Novitates, 296: 1-42.
Schmidt, J. 1925. On the distribution of freshwater eels (Anguilla) throughout the world. Memory Academic Royale Sciences Lettres, 8: 328-382.
Schultz, L. P. 1945. Fishes of the United States Antarctic Service Expedition 1939-1941. Proceeding of the American Philosophical Society, 89 (1): 298 pp.