Abstract
Lethrinus ravus is described from localities in the western Pacific. Photographic records also confirm its presence in Western Australia. It co-occurs with and is morphologically very similar to L. semicinctus but differs consistently in color pattern and average number of scales in the supratemporal patch of scales. Lethrinus semicinctus has a dark oblong blotch under the soft dorsal fin straddling the lateral line and a cluster of darkened scales in front of the base of the pectoral fin while L. ravus lacks these markings. Lethrinus ravus has black-lined scales that form rows above the lateral line and are scattered below the lateral line; this pattern is absent in L. semicinctus. Lethrinus ravus also frequently has more scales in the supratemporal patch than L. semicinctus. Both L. semicinctus and L. ravus have a cluster of scales with black lines above the base of the pectoral fin. This shared specialization is unique within Lethrinus and is evidence for a sister-species relationship.
References
Carpenter, K.E. (1996) Morphometric pattern and feeding mode in emperor fishes (Lethrinidae, Perciformes). In: Marcus, L.F., Corti, M., Loy, A., Naylor, G.J.P. & Slice, D.E. (Eds) Advances in Morphometrics. NATO Advanced Science Series, Series A, vol. 284, 479-487.
Carpenter, K.E. (2001) Lethrinidae. In: Carpenter, K.E. & Niem, V.H. (Eds) FAO Species Identification Guide for Fishery Purposes. The Living Marine Resources of the Western Central Pacific. Volume 5. Bony Fishes Part 3, FAO, Rome. pp. 3004-3050.
Carpenter, K.E. & Allen, G.R. (1989) FAO Species Catalogue Vol. 9. Emperor Fishes and Largeeye Breams of the World (Family Lethrinidae). An Annotated and Illustrated Catalogue of Lethrinid Species Known to Date, FAO, Rome. 119 pp.
Carpenter, K.E. & Johnson, G.D. (2002) A phylogeny of sparoid fishes (Perciformes: Percoidei) based on morphology. Ichthyological Research, 49, 114-127.
Cuvier, G. & Valenciennes, A. (1830) Histoire naturelle des poisons. Tome Sixième. Livre Sixième Partie I. Des Sparoïdes, Partie II. Des Ménides, Strasbourg, 599 pp.
Gloerfelt-Tarp, T. & Kailola, P.J. (1984) Trawled Fishes of Southern Indonesia and Northwestern Australia, Australian Development Assistance Bureau, Indonesian Directorate General of Fisheries, German Agency for Technical Cooperation, 406 pp.
Leviton, A.E., Gibbs, R.H. Jr., Heal, E. & Dawson, C.E. (1985) Standards in herpetology and ichthyology. Part 1. Standard symbolic codes for institutional resource collections in herpteology and ichthyology. Copeia, 1985, 802-832
LoGalbo, A., Carpenter, K.E., & Reed, D.L. (2002) Evolution of trophic types in emperor snappers (Lethrinus, Lethrinidae, Percoidei) based on Cytochrome b gene sequence variation. Journal of Molecular Evolution, 54, 754-762.
Sato, T. (1978) A synopsis of the sparoid fish genus Lethrinus with the description of a new species. University Museum, University of Tokyo Bulletin, 15, 1-70.
Smith, J.L.B. (1959) Fishes of the family Lethrinidae from the western Indian Ocean. Ichthyological Bulletin Rhodes University, 17, 285-295.
Walker, M.H. (1975) Aspects of the Biology of Emperor Fishes, Family Lethrinidae, in North Queensland Barrier Reef waters, Unpublished Ph.D. dissertation, Department of Zoology, James Cook University.
Wilson, G.G. (1998) A description of the early juvenile colour patterns of eleven Lethrinus species (Pisces: Lethrinidae) from the Great Barrier Reef, Australia. Records of the Australian Museum, 50, 55-83.