Synophis insulomontanus, Torres-Carvajal, Omar, Echevarria, Lourdes Y., Venegas, Pablo J., German Chavez, & Camper, Jeffrey D., 2015

Torres-Carvajal, Omar, Echevarria, Lourdes Y., Venegas, Pablo J., German Chavez, & Camper, Jeffrey D., 2015, Description and phylogeny of three new species of Synophis (Colubridae, Dipsadinae) from the tropical Andes in Ecuador and Peru, ZooKeys 546, pp. 153-179 : 164-168

Taxon classification Animalia Squamata Colubridae

Synophis insulomontanus sp. n.

Synophis insulomontanus Proposed standard English name: Mountain fishing snakes

Synophis insulomontanus Proposed standard Spanish name: Serpientes pescadoras monteses

Holotype.

Peru: Departamento Huánuco: Provincia Puerto Inca: Distrito Llullapichis: CORBIDI 13940 (Figs 10, 11), adult male from Campamento Peligroso-Reserva Comunal El Sira (9°25'34.22"S, 74°44'6.60"W, 1507 m), collected on 1 December 2013 by G. Chavez.

Paratypes.

Peru: Departamento San Martín: Provincia Picota: Distrito Shaboyacu: CORBIDI 9223 adult female from Parque Nacional Cordillera Azul, Puesto de Control 16 (Chambirillo) (7°4'8.90"S, 76°0'55.20"W, 1122 m), collected on 8 May 2011 by P. J. Venegas and V. Duran and CORBIDI 10418, from same locality, collected on 20 February 2012 by V. Duran. Departamento Huánuco: Provincia Huánuco: Distrito Chinchao: CORBIDI 13705 adult male from Miraflores (9°40'40.60"S, 75°50'11.09"W, 1798 m), collected 8 December 2013 by V. Duran and L. Lujan.

Diagnosis.

Synophis insulomontanus can be distinguished from other species of Synophis by having a semicapitate, bilobed hemipenis with a large lateral spine at the base of the hemipenial body, and the sulcus spermaticus bifurcating on the center of the hemipenial body (Fig. 12); 19 longitudinal rows of dorsals at midbody; strongly keeled dorsals except for first row, which is keeled to a lesser extent; 151-152 ventrals in males, 147-149 in females; 108-109 subcaudals in males, 103 in females. Scutellational characters of all recognized species of Synophis are presented in Table 3.

Description of the holotype.

Adult male (Figs 5, 10, 11), SVL 335.3 mm; tail length 180.9 mm; eye diameter 1.46 mm; pupil round; head width 6.7 mm at level of supralabial 6; head length 11.07 mm from snout to posterior margin of jaw; width at midbody 6.48 mm; head distinct from neck.

Prefrontals fused in a roughly pentagonal scale, wider than long; frontal single, pentagonal, posterior suture angular with apex directed posteriorly, wider than long; parietals large, paired, longer than wide; loreal trapezoidal, almost two times longer than high; preocular single, bordering anterior margin of orbit; supraocular single, bordering dorsal margin of orbit; temporals 1+3+3; anterior temporal more than two times longer than high; posterior temporals two times longer than high, approximately one half the length of anterior temporal; internasals in contact medially, wider than long; nasals not in contact; rostral visible from above, concave, nearly two times wider than long, in contact with first supralabials, nasals, and internasals; mental triangular, in contact with first pair of infralabials; infralabials 11/11; supralabials 8/8 (fourth and fifth entering orbit on both sides); anterior genials three times longer than wide, bordered laterally by infralabials 1-6 on both sides; posterior genials two times longer than wide, separated by gulars, and bordered laterally by infralabials 6-7 on both sides; dorsal scale rows 20-19-19, first dorsal row moderately keeled from ventral 7, other rows strongly keeled; anal single; ventrals 151; subcaudals 108, paired.

Hemipenial morphology.

The following description is based on the left hemipenis of the holotype (Fig. 12; CORBIDI 13940). The fully everted and maximally expanded organ is bilobed, semicalyculate, semicapitate, and extends to the fifth subcaudal. Capitular grooves are present on the asulcate side; capitula are ornamented with calcified papillae, remarkably larger on the asulcate side. A few papillae meet on the asulcate side of the lobular crotch. The sulcus spermaticus bifurcates on the center of the hemipenial body and its branches extend centrolineally to the tip of each lobe. Papillae are relatively small on the sulcate side of the hemipenial body between the bifurcating branches of the sulcus spermaticus. The hemipenial body is ornamented with large calcified spines, except on the medial region of the asulcate side and near the sulcus spermaticus, where the spines are very small. One spine on the left side (sulcate view) is considerably longer than the others. Very small spines cover the base of the hemipenial body.

Color in life of the holotype

(Fig. 5). Dorsal surface of head, body and tail uniformly dark grey; skin among scales on flanks cream, visible on anterior half of body; first five ventrals cream, becoming progressively pigmented with grey, except on their posterior margin where cream pigmentation is always present; anal plate grey with cream posterior border; subcaudals grey, with the porsterior borders weakly pigmented with cream in some scales; sides of head and 1st supralabial same tone of grey as dorsal surface, other supralabials mostly cream; first three infralabials mostly grey, others mostly cream; scales on throat with a pale blue tone.

Variation.

Intraspecific variation in scale counts and measurements in Synophis insulomontanus is presented in Table 3. Two or three scales can be present on second row of temporals, three in the holotype and CORBIDI 9223, and two in CORBIDI 10418 and CORBIDI 13705. Paratype CORBIDI 10418 has 21 dorsals at midbody. No major differences were found between the hemipenis of the holotype and that of paratype CORBIDI 13705, except that the latter has more papillae between the bifurcating branches of the sulcus spermaticus on the sulcate side of the hemipenial body. Specimen CORBIDI 10418 has a dense cream pigmentation on ventrals from anterior end of body to midbody.

Distribution and natural history.

Synophis insulomontanus is known to occur between 1122-1798 m on the Amazonian slopes of the Andes in northern and central Peru (Fig. 6). Two localities within Departamento Huánuco, Cordillera Azul and Cordillera El Sira, correspond to sub-Andean mountain ridges, whereas the locality of Miraflores lies on the Amazonian slopes next to the Huallaga River.

The holotype was found at night, coiling inside a bromeliad, 1 m above the ground in primary premontane forest. Other specimens were found active at night, moving through leaf litter. Specimens from Cordillera Azul (CORBIDI 9223 and 10418) were found in primary premontane forest, whereas specimen CORBIDI 13705 from Miraflores, Huánuco, was found in secondary montane forest.

Etymology.

The epithet insulomontanus is a noun that derives from the Latin words insulo (= isolated) and montanus (= mountain). It refers to the isolated mountain ridges in Departamento Huánuco, where the new species was discovered.