Centroscymnus owstonii Garman, 1906

Fernando, Daniel, Bown, Rosalind M. K., Tanna, Akshay, Gobiraj, Ramajeyam, Ralicki, Hannah, Jockusch, Elizabeth L., Ebert, David A., Jensen, Kirsten & Caira, Janine N., 2019, New insights into the identities of the elasmobranch fauna of Sri Lanka, Zootaxa 4585 (2), pp. 201-238 : 233

Centroscymnus owstonii Garman

( Figs. 5F , 19 A–C)

Two specimens (SL-92 and SL-93) of Centroscymnus Barboza du Bocage & de Brito Capello were also collected from the deep-sea longline landing site in Mutur in the Eastern Province. Morphologically these specimens are consistent with Centroscymnus owstonii following Weigmann et al. (2016). In the tree resulting from our Neighbor-Joining analysis of NADH2 data, these specimens grouped most closely with our reference specimen of C. owstonii from Portugal. The two specimens from Sri Lanka differ from each other by 2 bp; one is identical to the reference specimen. A mature male has been deposited in the BRT Ichthyology Collection (SL-93; BRT-I 0024).

To our knowledge, this is the first documented report of this family, genus, and species from Sri Lanka. It is also the first record of this genus from the northern Indian Ocean.

Figures

FIGURE 5. Neighbor-Joining trees of p-distances based on 1,044 bp of aligned NADH2 sequence data for individual selachian genera or groups of genera. Taxon names are followed by country, host specimen number (in parentheses), and GenBank number. Outgroup taxa used in each analysis were omitted from the individual trees. Scale bar values indicate substitutions per site. Specimens deposited in the Blue Resources Trust Ichthyology Collection are indicted by stars (see text for details). A. Echinorhinidae. B. Hexanchidae. C. Lamniformes. D. Chiloscyllium (Hemiscylliidae). E. Centrophorus (Centrophoridae). F. Somniosidae/Oxynotidae (Somniosus omitted).

FIGURE 19. Centroscymnus owstonii (Somniosidae). A. Lateral view of mature male (SL-93; BRT-I 0024). B. Ventral view of mature male (SL-93; BRT-I 0024). C. Teeth of upper and lower jaw of mature male (SL-93; BRT-I 0024).