Acroteriobatus variegatus (Nair & Lal Mohan)

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 : 219-220

Acroteriobatus variegatus (Nair & Lal Mohan)

( Figs. 3C , 12A,B )

Four specimens (SL-99, SL-100, SL-102, and SL-103) of a relatively small guitarfish were collected at the landing site in Mutur in the Eastern Province. These specimens exhibited anterior nasal flaps that extended well into the internarial space, placing them in the genus Acroteriobatus Giltay (see Ebert 2014a; Last et al. 2016b). Their color pattern, in combination with their possession of small thorns near the orbits and spiracles as well as a conspicuous mid-dorsal row of small thorns, fits the description of A. variegatus (see Nair & Lal Mohan 1973), which was originally reported from the Gulf of Mannar, India. As NADH2 data for a specimen of this species of confirmed identity are not available, we were unable to confirm this identification using molecular data. However, NADH2 sequence data were generated for all four specimens and they were included in our Neighbor-Joining analysis. These specimens differed from one another by 1–5 bp; in comparison, these specimens differed from our reference specimen of Acroteriobatus annulatus (Müller & Henle) (AF-156; JQ518915 ) from South Africa, the only other member of this genus included in the analysis, by 100–106 bp. An immature male of this species was deposited in the BRT Ichthyology Collection (SL-99; BRT-I 0027).

The distribution of this species in the map presented by Ebert (2014a) includes the northwestern coast of Sri Lanka. However, to our knowledge, this is the first formal report of this species from the country.

Figures

FIGURE 3. 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. Gymnura (Gymnuridae). B. Rhinoptera (Rhinopteridae). C. Acroteriobatus and Rhinobatos (Rhinobatidae). D. Torpediniformes.

FIGURE 12. Acroteriobatus variegatus (A, B) and Rhinobatos annandalei (C, D) (Rhinobatidae). A. Dorsal surface of immature male (SL-99; BRT-I 0027). B. Ventral snout and oronasal region of immature male (SL-99; BRT-I 0027). C. Dorsal surface of female (SL-115; BRT-I 0003). D. Ventral snout and oronasal region of female (SL-115; BRT-I 0003). E. Dorsal surface of immature male (SL-28). F. Oronasal region of immature male (SL-28).