New Rainbow Sardine Species of Dussumieria (Teleostei: Clupeiformes: Dussumieriidae) from the East African Coast
Dussumieria torpedo, new species, is described from 18 specimens collected off the East African coast from Tanzania to South Africa. The new species closely resembles Dussumieria albulina in that both species have a deep body and a parasphenoid without teeth. However, D. torpedo, new species, is distinguished from D. albulina by having small pores posteriorly on the body scales (vs. numerous longitudinal striae posteriorly in D. albulina), a longer maxilla (33.4–34.9% of head length vs. 30.4–34.9% [less than 33.3% in specimens larger than 85 mm standard length]) and mandible (48.5–51.9% of head length vs. 44.8–50.6%), a greater number of pseudobranchial filaments (19–23 vs. 17–21), and indistinct melanophores scattered on the pectoral-fin rays (vs. distinct). A molecular analysis, which compared nucleotide sequences of the mitochondrial cytochrome oxidase I (COI) gene of the new species with those of all other valid species of Dussumieria, revealed that D. torpedo, new species, has >9% mean p-distance divergence from its congeners.
Holotype of Dussumieria torpedo, new species, BMNH 1966.11.16.426, 137.4 mm SL, off Kama, Zanzibar Channel, Tanzania.
Photograph of stained lateral body scale of Dussumieria torpedo, new species (BMNH 1983.4.8.12–13, 119.4 mm SL, Mafia Channel, Tanzania; scale from just below dorsal-fin base); alizarin Red S stain. Arrows indicate pores on posterior part.
Pectoral-fin rays of the holotype of Dussumieria torpedo, new species (BMNH 1966.11.16.426, 137.4 mm SL, Kama, Zanzibar Channel, Tanzania; preserved condition).
Ventral view of roof of mouth of Dussumieria torpedo, new species (NSMT-P 138481, 129.7 mm SL, off Kama, Zanzibar Channel, Tanzania); PL, palatine; PT, pterygoid; alizarin Red S stain.
Relationships of (A) maxilla length (as % of head length; HL), (B) mandibular length (as % of HL), and (C) counts of pseudobranchial filaments to standard length in Dussumieria torpedo, new species (circles), and D. albulina (triangles).
Maximum-likelihood phylogenetic tree of all valid species of Dussumieria (Clupeiformes: Dussumieriidae), based on cytochrome oxidase I gene (total: 648 characters). Specimens of Dussumieria each identified by museum lot number followed by either specimen code or GenBank sequence accession number (see Table 1 for details). Tree rooted at midpoint; branch lengths proportional to number of substitutions; numbers at nodes indicate bootstrap proportions (when >75%). See Data Accessibility for tree file.
Contributor Notes
Associate Editor: M. T. Craig.