Himantura tutul Borsa, Durand, Shen, Arlyza, Solihin & Berrebi, 2013

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 : 208

Himantura tutul Borsa, Durand, Shen, Arlyza, Solihin & Berrebi

( Figs. 2C , 7 A–C)

Eight specimens consistent in coloration with the Himantura uarnak (Gmelin) species complex were examined. These came from Palkanththura (SL-1), Pukulam (SL-8, SL-10), Baththalangunduwa Island (SL-12), and Puttalam (SL-14) landing sites in the North Western Province, and the Munai (SL-34, SL-42) and Kottadi (SL-61) markets in Point Pedro in the Northern Province. The dorsal surface of the disc of all four immature specimens (SL-1, SL- 12, SL-34, and SL-61) had regular brown spots on a yellow or pale brown background. However, somewhat marked color pattern differences were seen among the four adult specimens. In two cases (SL-8 and SL-10), the dorsal surface of the disc is yellow to gray and bears numerous small spots that are essentially ocelli. In two other cases (SL-14 and SL-42), the dorsal surface of the disc is yellow and bears numerous, small, brown, irregular, elongate spots. However, the eight specimens differed from one another by only 0–4 bp and are thus likely conspecific. In terms of the identity of the Sri Lankan material, in the tree resulting from the Neighbor-Joining analysis, which included reference sequences of all five described members of the genus as well as the two undescribed species recognized by Naylor et al. (2012a) as Himantura uarnak 1 and Himantura uarnak 4, the specimens from Sri Lanka grouped most closely with the reference sequence of H. tutul (KA-48; JQ518800 ; formerly H. uarnak 3 of Naylor et al. 2012a) from Indonesian Borneo. Although the specimens from Sri Lanka differed from this specimen by 10–14 bp, the color pattern variation seen in our specimens from Sri Lanka is consistent with that seen in H. tutul by Borsa et al. (2013) and Borsa (2017a). We have assigned this name to these specimens at this time based on the following lines of evidence. (1) Our reference specimen (provisionally assigned the name H. uarnak 3 by Naylor et al. 2012a) from Indonesia Borneo (i.e., KA-48) was also included in the molecular analyses of NADH2 sequence data by Last et al. (2016a) who determined it to be conspecific with the three specimens from Tanzania (identified as H. uarnak ) included in their analyses. (2) Results of unpublished analyses that included NADH2 sequence data for a specimen of H. uarnak we collected from its type locality in the Red Sea place this specimen as sister taxon to H. leoparda Manjaji-Matsumoto & Last , well away from our reference specimen of H. uarnak 3, suggesting that the name H. uarnak is not the appropriate name for the latter taxon. (3) Given point 1 above and the fact that the type locality of H. tutul is Tanzania, the latter name is the most appropriate to be applied to specimens provisionally identified as H. uarnak 3. (4) Given the specimens from Sri Lanka cluster with our reference specimen of H. uarnak 3, these specimens should also be referred to as H. tutul at this time. However, conspecificity of these forms remains provisional until a substantially greater amount of morphological work can be conducted, especially given the extensive color pattern variation seen across the H. uarnak species complex (e.g., Borsa et al. 2013, 2017a; Manjaji-Matsumoto & Last 2016).

This is likely the species generally referred to as H. uarnak in Sri Lanka (see De Bruin et al. 1995; Morón et al. 1998; De Silva 2006). In addition, although no specimens or references were cited, Borsa et al. (2013) listed the Laccadive Sea as part of the distribution of H. tutul suggesting they have evidence that this species occurs at least off the west coast of Sri Lanka.

Figures

FIGURE 2. Neighbor-Joining trees of p-distances based on 1,044 bp of aligned NADH2 sequence data for individual batoid 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. Aetobatus (Aetobatidae). B. Brevitrygon (Dasyatidae). C. Himantura (Dasyatidae). D. Maculabatis (Dasyatidae). E. Neotrygon (Dasyatidae). F. Pastinachus (Dasyatidae). G. Pateobatis (Dasyatidae). H. Urogymnus (Dasyatidae).

FIGURE 7. Himantura tutul (A–C) and Himantura undulata (D) (Dasyatidae). A. Dorsal surface of mature female (SL-8); inset showing scapular denticles. B. Dorsal surface of mature female (SL-42); inset showing scapular denticles. C. Dorsal surface of immature male (SL-34); inset showing scapular denticles. D. Dorsal surface of immature male (SL-33); inset showing scapular denticles.