Friday, April 28, 2017

[Herpetology • 2017] Distinction of Gracixalus carinensis from Vietnam and Myanmar, with Description of A New Species, Gracixalus sapaensis, from northwestern Vietnam

Gracixalus sapaensis  Matsui, Ohler, Eto & Tao, 2017

Figure 3. Dorsal (A) and dorsolateral (B) views of male holotype (MNHN 1999. 5961) of Gracixalus sapaensis sp. nov. in life.

Gracixalus carinensis was originally described from Myanmar, but samples of the species reported in molecular phylogenetic works were all from Vietnam, far apart from the type locality. Moreover, the voucher specimens used for sequencing seem to have never been critically studied. We newly sequenced specimens from Vietnam and also closely examined morphology of vouchers. As a result, we confirmed that samples treated under this name from Vietnam constitute a single species. Although no molecular data are available for topotypic samples from Myanmar, detailed morphological comparisons revealed that samples from Vietnam are constantly separated from the topotypic samples of G. carinensis by much poorly developed toe webbing. We thus consider the Vietnamese samples as an undescribed species and describe them as Gracixalus sapaensis sp. nov.

Gracixalus sapaensis sp. nov. 

Synonymy. Philautus carinensis: Ohler, Marquis, Swan & Grosjean, 2000, Herpetozoa, 13: 71-87;
Aquixalus (Aquixalus) carinensis: Delorme, Dubois, Grosjean & Ohler, 2005, Bulletin Mensuel de la Société Linnéenne de Lyon, 74: 166;
 Kurixalus carinensis: Nguyen, Ho & Nguyen, 2009, Herpetofauna of Vietnam: 527;
Gracixalus carinensis: Li, Che, Murphy, Zhao, Zhao, Rao & Zhang, 2009, Molecular Phylogenetics and Evolution, 53: 509.

Etymology. The specific epithet is derived from Sa Pa, a district in Lao Cai Province, northern Vietnam, where the new species occurs.

Range. Known only from northwestern Vietnam (fig. 5): Lai Chau, Lao Cai and Dak Lak (Nguyen et al., 2009, as Aquixalus). The known localities vary from 1250-2340 m in altitude. 

Natural history. Ohler et al. (2000) reported the new species to occur at all the vegetation types they classified (agriculture, scrub, submontane forest, and montane forest) from 1260-2020 m a.s.l. on Fan Si Pan mountains. Specimens were usually found sitting on leaves, rarely branches, up to 2 m from the ground, in the vicinity of mountain streams (median distance observed 3 m). They also reported the new species (as Philautus carinensis) to breed mainly in October-November unlike Ph. odontotarsus (now Kurixalus), and Ph. jinxiuensis and Ph. gracilipes (both now Gracixalus) that breed in July. 

Masafumi Matsui, Annemarie Ohler, Koshiro Eto and Nguyen Thien Tao. 2017. Distinction of Gracixalus carinensis from Vietnam and Myanmar, with Description of A New Species. ALYTES. 33(1-4); 25-37.