Teretrurus sanguineus ( Beddome, 1867 )

Ganesh, S. R. & Channakeshava Murthy, B. H., 2022, Taxonomy of the shieldtail snake genus Teretrurus Beddome, 1886 (Serpentes: Uropeltidae) with a revised key and remarks on the geographic gaps in the Western Ghats, Peninsular India, Records of the Zoological Survey of India 122 (1), pp. 25-35 : 28-29

Teretrurus sanguineus ( Beddome, 1867)

( Figure 1 , 2 , 3 )

1867. Plectrurus sanguineus Beddome, Madras Quart. J.Med. Sci. , 11: 14. 1876. Plectrurus scabricauda Theobald, Descr. Catl. Reptiles Brit. Ind. , p. 136.

Material examined (n=3): CSPT /S- 10 female from Anamalai, date unknown ; MAD no number male from Kavalai, Cochindate unknown ; SACON /VR- 46 female coll. S. Bhupathy from Anamalai, date unknown .

Taxonomic History: This species was first described as Plectrurus sanguineus by Beddome (1867) based on holotype from Anamalai forests above Ponachi [=Pollachi; Wallach et al., 2014] (10.446˚ N 76.984 ˚E; 900 m asl). Beddome (1886) whilst describing the genus Teretrurus , rightly allocated his P. sanguineus , as the type species, giving it the current name combination ( Smith, 1943). A subjective junior synonym Plectrurus scabricauda Theobald, 1876 described based on the holotype ZSI 6996 (stated to be lost fide Das et al., 1998, but present in the collection – N.S. Achyuthan pers. comm. in May 2021) from Anamallays exists ( Beddome, 1886; Boulenger, 1893; Smith, 1943; Pyron et al., 2016).

Remarks: Boulenger (1893) listed six specimens (1 male, 3 females, 2 juveniles) all with the locality data stated as “Anamallays” (sic) with a ventral range of 128-147. We agree with subsequent workers that as Beddome (1867) in his original description elaborated on only one specimen with 144 ventrals and 7 subcaudals, that specimen is the name-bearing type, the holotype ( Pyron et al., 2016). Wallach et al. (2014) had opined that specimen to be the lectotypebut the original description ( Beddome, 1867) makes no indication of any other specimen but for the described one and hence it was corrected by Pyron et al. (2016). In either case, the rest of the five specimensin that lot, with differing ventral counts, have no name-bearing status. Pyron et al. (2016) also commented that Boulenger’s ventral values of those 6 specimens did not match with that of Beddome’s count (144), but herein the authorsopine that one specimen’s count (147) is the closest to Beddome’s count. As explained above, owing to the large ventral count range (120-150) ( Boulenger, 1893), Boulenger’s statement that these specimens originate only from the Anamallays is most likelyincorrect. But the type specimen (with 144 or 147 ventrals) is consistent with what is generally the ventral value for the Anamalai population of Teretrurus . Beddome (1867) stated in his original description, the dorsal scale rows count to be 17. Usually, it is understood as midbody count. But the value 17 was later reported as a miscount, the correct value of midbody count being 15 ( Boulenger, 1893; Constable, 1949).

Differential Diagnosis: A species of Teretrurus endemic to the Anamalai Hills, possessing a distinct supraocular scale (vs. lacking in T. rhodogaster ), with much higher ventral counts 142-150 (vs. 120-128 in T. hewstoni ; 130- 136 in T. travancoricus ).

Description and variation: Measurements in mm: snoutvent length: 150-190; tail length: 2.5-6; head length: 4.5- 5.5; head width: 4-5; body width 4.5-6; eye diameter: 0.8; eye-snout distance: 1.8; inter-orbital distance: 2-2.5; inter-narial distance: 0.5-0.7. Habitus: Small-bodied, trunk cylindrical to slightly compressed, especially near tail; body fairly slender; head not distinct from neck, as wide as midbody; snout obtusely rounded in profile; tail small, suddenly tapering to a sharp, finepoint. Scalation: scales smooth, cycloid, without apical pits; head scales lacking pre-, post-oculars; supraocular and temporal present; eye covered under ocular scale, partially fused; mental groove absent; dorsal scales in 16:15:15 rows, with 16 -->15 at 36-38th ventral scale; supralabials 4/4; infralabials 4/4; ventrals 144-149; subcaudals 7-9 pairs; terminal caudal scales rather smooth, with a single sharp projection in the end. Coloration: dorsum dark to coffee brown, rather uniform and unpatterned; venter rich red (turning creamy yellow in preservative) with a few black patches; eye black.

Plectrurus scabricauda Holotype ZSI 6996 Annamallay: Measurements in mm: Snout to vent length 159; tail length 13; head length 5; head width 3.5; Habitus: a rather soft and brittle specimen; body slightly damaged at mid portion due to preservation artifact; trunk subcylindrical to mildly dorso-ventrally depressed at places, owing to long-time preservation; head small, snout pointed to slightly ovoid in profile; Scalation: dorsal scale rows 13:15:13 scales smooth, cycloid, without apical pits; scales on head wrinkled, due to long-time preservation; eyes covered under ocular scales; supraocular and temporal present; preocular, postocular, loreal and mental groove absent; supralabials 4/4; infralabials 4/4; ventrals 141, subcaudals 11 pairs; terminal caudal scales equally wrinkled as head scales, due to preservation artifact. Coloration: dorsum drab greyish brown, venter creamy orange, except towards body extremities (mental and subcaudals) which present with patches of darker shades; eye grey.

Distribution and Natural History: In a relativelyrestricted sense (as re-appraised hereinincl. P. scabricauda ), T. sanguineus is definitely known only from Anamalai-Munnar ranges ( Beddome, 1867). It is perhaps the only congener that partly co-occurs with another congener T. rhodogaster that inhabits a much easterly and higher elevation range (Palni Hills). Rajendran (1985) mentioned of having collected this species from Nyamakkad of Kannan Devan Hills (10.151˚N, 77.080˚E; 1870 m asl) near Munnar. This apparently rare species has not been recently sighted anywhere in the Anamalai (museum holding records in Boulenger, 1893; Constable, 1949), despite surveys that covered at least some parts of this massif ( Roux, 1928; Kumar et al., 2001).

Figures

Figure 1. Map of southern India showing the distribution of Teretrurus species, in the Western Ghats.

Figure 2. Preserved specimens of Teretrurus species: (a) T. travancoricus ZSI/WGRC/2135-6, (b) T. hewstoni ZSI/WGRC/3124, (c) T. sanguineus CSPT/S-10, (d) T. rhodogaster CSPT/S-14. Photos: S. R. Ganesh.

Figure 3. Holotype of Plecturus scabricauda ZSI 6996 coll. from Anamallays: (a) entire view, (b) jar label, (c) head right view, (d) head left view, (e) head ventral view, (f) tail ventral view. Photos: N.S. Achyuthan.