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| Lethrinus mitchelli Allen, Victor & Erdmann, 2021 |
Abstract
A new species of emperor fish, Lethrinus mitchelli, is described on the basis of three specimens, 109.4–111.3 mm SL, collected from 20 m at the East Cape region of Milne Bay Province, Papua New Guinea. It is similar to the sympatric relatives L. semicinctus and L. rubrioperculatus, but differs in color pattern and has a narrower cheek (cheek height 3.2–3.6 in head length vs. 2.4–2.9). Other diagnostic features include head length (2.7 in SL) greater than body depth (3.0–3.1 in SL); the snout excluding the lip 1.3–1.4 in cheek height; the snout profile nearly straight, without a prominent hump, and about 55° to the upper jaw; conical lateral jaw teeth; the interorbital area nearly flat or convex; the fourth dorsal-fin spine longest; lateral-line scales 47; transverse scale rows below and above the lateral line 15 and 4.5 rows; and a fully-scaled area adjacent to the prominent bony spine at the posteriormost margin of the opercle (excluding fleshy flap). The new species has a distinctive color pattern: brown dorsally, whitish ventrally, with a broad, brown, posteriorly tapering band on the midlateral body, partially split anteriorly by a relatively broad, ascending diagonal white band. Lethrinus mitchelli is 6.11% sequence divergent (pairwise) in the mtDNA COI marker from its nearest relative, L. semicinctus, also from the East Indies. A table of COI divergences among mtDNA lineages assigned to 27 of the 28 known species of Lethrinus shows a set of distinctly different lineages, from 3.32% to 20.85% divergent from each other (minimum interspecific distances).
Key words: taxonomy, ichthyology, phylogenetics, coral reef fishes, Indo-Pacific, DNA barcodes, mtDNA COI
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| Lethrinus mitchelli n. sp. blotchy pattern on rubble bottom, about 200 mm SL, East Cape Region, Milne Bay Province, Papua New Guinea preserved holotype, 110.1 mm SL, East Cape Region, Milne Bay Province, Papua New Guinea. photos: G.R. Allen. |
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| Lethrinus mitchelli n. sp. [upper] about 200 mm SL, East Cape Region, Milne Bay Prov., Papua New Guinea; [lower] blotchy pattern on rubble bottom, about 200 mm SL, East Cape Region, Milne Bay Province, Papua New Guinea. photos: G.R. Allen |
Allen, G.R., Victor, B.C. and Erdmann, M.V. 2021. Lethrinus mitchelli, A New Species of Emperor Fish (Teleostei: Lethrinidae) from Milne Bay Province, Papua New Guinea. Journal of the Ocean Science Foundation. 38, 66–77. DOI: doi.org/10.5281/zenodo.5172763
