Saturday, June 16, 2018

[Herpetology • 2018] Sitana gokakensis & S. thondalu • Two New Endemic and Cryptic Species of Sitana Cuvier, 1829 from peninsular India

Sitana gokakensis  S. thondalu 
Deepak, Khandekar, Chaitanya & Karanth, 2018

Two new cryptic species of the agamid genus Sitana Cuvier, 1829 from Peninsular India are described herein. Sitana gokakensis sp. nov. from Gokak, Karnataka closely resembles Sitana thondalu sp. nov. from Nagarjuna Sagar, Andhra Pradesh. The two species can be distinguished based on their subtle morphological differences, genetic difference and geographic distribution. Sitana gokakensis sp. nov. have a relatively depressed head compared to Sitana thondalu sp. nov. Additionally, the vertebral scale counts differ in females of the two new species (Sitana gokakensis sp. nov. 45–47 vs Sitana thondalu sp. nov. 49–53). Genetic divergence between them is comparable to those between previously described Sitana species. Furthermore, the two new species are distributed ca. 500 km apart and are endemic to their respective landscapes that lie in similar latitudes of peninsular India. We urge the use of large sample size in new species descriptions especially those dealing with cryptic species like Sitana. The discovery of the two new cryptic species from these rocky terrains in peninsular India highlights need for more herpetological exploration in this region.

Keywords: Reptilia, cryptic species, DNA, fan-throated lizards, peninsular India, Sitana, taxonomy 

FIGURE 9. Sitana gokakensis sp. nov. colouration in life. uncollected adult females from the type locality.

Sitana gokakensis sp. nov.

Etymology. The specific epithet is an adjectival toponym and refers to the Gokak plateau of Belagavi district in Karnataka, to which this species is endemic.
Suggested common name. Gokak fan-throated lizard.

Distribution. Sitana gokakensis sp. nov. is endemic to Gokak plateau in Belagavi district, Karnataka (Fig. 1). The samples collected from north and south outside this plateau (Nipani, Ramdurga, Bagalkot) were of S. laticeps. The Ghataprabha is a rocky river and a potential geographical barrier for this species.

Sitana thondalu sp. nov.

Etymology. The specific epithet is a noun in apposition, derived from the Telugu word thondalu for an agamid lizard in Andhra Pradesh and Telangana states.
Suggested English name. Nagarjuna Sagar fan-throated lizard

Distribution. Sitana thondalu sp. nov. is found in Macherala and Nagarjuna Sagar, Guntur District, in Andhra Pradesh state. This species was only recorded from these two localities during this study (Fig. 1). The altitudinal distribution is between 180 and 200 m a.s.l.

 Sitana gokakensis sp. nov. colouration in life. 
Holotype (BNHS 2490) in life.

  Sitana thondalu sp. nov. colouration in life. 
Holotype (BNHS 2492) in life.

V. Deepak, Akshay Khandekar, R. Chaitanya and Praveen Karanth. 2018. Descriptions of Two New Endemic and Cryptic Species of Sitana Cuvier, 1829 from peninsular India. Zootaxa. 4434(2); 327–365.  DOI:  10.11646/zootaxa.4434.2.5