A new species of Ninia (Serpentes, Colubridae) from western Ecuador and revalidation of N. schmidti Author Arteaga, Alejandro https://orcid.org/0000-0002-0014-3728 Khamai Foundation, Quito, Ecuador & Tropical Herping S. A., Quito, Ecuador af.arteaga.navarro@gmail.com Author Harris, Kyle J. Department of Biology, Liberty University, Lynchburg, Virginia, USA text Evolutionary Systematics 2023 2023-12-07 7 2 317 334 http://dx.doi.org/10.3897/evolsyst.7.112476 journal article http://dx.doi.org/10.3897/evolsyst.7.112476 2535-0730-2-317 2D3CA9C524E24EF484BF174362F70EBC 73FC5B652BFB5F618B4CC37B2E32EE5D Ninia guytudori sp. nov. Figs 3 , 4a , 5a-d , 6 , 7b Holotype. JMG 1327 (Figs 3 , 4a , 5a-b ), adult female collected by Alejandro Arteaga on July 27, 2017 at road to Mindo, Pichincha province, Ecuador ( -0.02825 , -78.76189 ; 1676 m). Figure 3. Female holotype of Ninia guytudori sp. nov. JMG 1327 in ( a ) dorsal and ( b ) ventral view. Figure 4. Lateral views of the head in two species of Ninia : ( a ) N. guytudori sp. nov. JMG 1327; ( b ) N. schmidti comb. nov. TH 503. Figure 5. Dorsal and lateral views of the head in two species of Ninia : ( a, b ) N. guytudori sp. nov. JMG 1327; ( c, d ) N. guytudori sp. nov. SC 005; ( e, f ) N. schmidti comb. nov. SC 095; ( g, h ) N. schmidti comb. nov. SCA 1374. Paratopotype. SC 005 (Fig. 5c, d ), juvenile male with the same data as the holotype. Proposed standard English name. Tudors's Coffee-Snake. Proposed standard Spanish name. Culebra cafetera de Tudor. Diagnosis. Ninia guytudori sp. nov. is placed in the genus Ninia , as diagnosed by Dunn (1935) , based on phylogenetic evidence (Fig. 1 ). The species is diagnosed based on the following combination of characters: (1) 19/19/19 keeled dorsals; (2) two postoculars or none in SC 005; (3) loreal 1.6-1.7 x longer than high; (4) temporals 1+2; (5) seven or eight supralabials, usually fourth and fifth contacting orbit; (6) seven or eight infralabials, first four or five contacting chin shields; (7) two rows of chin shields; (8) two or three preventrals; (9) 130-138 ventrals in males, 144 in the single female; (10) 48-51 subcaudals in males, 44 in the single female; (11) dorsal ground color uniformly black with a white nuchal collar that connects to a white lip band forming a bridle (Fig. 6 ); (12) ventral surfaces uniformly immaculate white (Fig. 3b ); (13) 181-243 mm SVL in males, 183 mm in the single female; (14) 30-58 mm CL in males, 35 in the single female. Figure 6. Photographs of some specimens of Ninia guytudori sp. nov. in life: ( a ) from Rio Manduriacu Reserve, Imbabura province; ( b ) from Santa Lucia Cloud Forest Reserve, Pichincha province. Photos by Jose Vieira. Comparisons. Ninia guytudori sp. nov. is compared to other species of the genus previously subsumed under N. atrata sensu lato (differences summarized in Table 1 ). The new species differs from all of them by having a white nuchal collar merged with the white lip coloration (Fig. 4a ), immaculate throat and chin shields (Fig. 5b, d ), and ventral surface of body immaculate white (Fig. 3b ). In N. schmidti comb. nov., the throat and chin shields are obscured by dark brown pigment (Fig. 5f, h ), the supralabials are partly or entirely black or dark gray (Fig. 4b ), nuchal collar absent in adults (Fig. 5e, g ), and ventral surfaces usually heavily obscured by dark pigment. Ninia guytudori sp. nov. further differs from N. teresitae by having a lower number of ventrals in males (130-138 vs 143-156), presence of a "white bridle," and belly not irregularly spotted, speckled, or heavily obscured by dark pigment. The cis-Andean N. hudsoni has black lips and dorsal scales arranged in 21 or 23 rows at mid-body (Suppl. material 1; Camper et al. 2021 ). Ninia guytudori sp. nov. differs from trans-Andean populations of N. atrata by having a white (instead of red, orange, or yellow) nuchal collar ( Angarita-Sierra 2009 ), ventral surface of tail obscured by dark gray pigment (instead of uniformly cream; Angarita-Sierra and Lynch 2017 ), nasal divided, and by having the sulcate surface of the hemipenial body ornamented with a large basal hooked spine (photo of QCAZR 11960 depicted in Guerra-Correa 2020 ). Table 1. Differences in coloration, scale counts, and size between snakes of the genus Ninia inhabiting western Ecuador. The range of each continuous variable is from our own sample, Angarita-Sierra and Lynch (2017) , and Angarita-Sierra (2018) . The numbers in parentheses represent the sample size.
Variable Ninia guytudori sp. nov. Ninia schmidti comb. nov. Ninia teresitae
Throat and chin shields Immaculate Obscured by dark brown pigment Irregularly spotted
Supralabials White (juveniles) or white with faint dark speckling Partly or entirely black or dark gray Partly or entirely black or dark gray
Nuchal collar in adults Present, entirely white or suffused with dark speckling Absent; if present, obscured by dark smudges and spots Absent
Nuchal collar in juveniles White, immaculate, connected with white supralabials, creating a "bridle" Present, with black spots White with black spots, no "bridle"
Supralabials White (juveniles) or white with faint dark speckling Partly or entirely black or dark gray; dingy white in ZMH R10390 Partly or entirely black or dark gray
Ventral surfaces of body Immaculate white Immaculate to heavily obscured by dark pigment Irregularly spotted, speckled, or heavily obscured by dark pigment
Pocket-shaped structure at the base of the hemipenial body Absent Absent Present
Sex Males (n = 4) Females (n = 1) Males (n = 4) Females (n = 4) Males (n = 10) Females (n = 15)
Maximum SVL 243 mm 183 mm 283 mm 409 mm 382 mm 346 mm
Ventral scales 130-138 138 138-144 139-155 143-156 148-160
Subcaudal scales 48-51 44 50-57 46-53 57-69 53-63
Table 2. Partition scheme and models of evolution used in phylogenetic analyses. Numbers in parentheses indicate codon position.
Partition Best model Gene regions Number of aligned sites
1 GTR+I 16S, CYTB(3), ND4(1), RAG1(1) 1517
2 HKY+I CYTB(1), ND4(2), RAG1(2) 740
3 HKY+G CYTB(2), ND4(3) 453
3 K80 RAG1(3) 285
Figure 7. Lateral views of some specimens of Ninia from western Ecuador in life: ( a ) N. schmidti comb. nov. SCA 1446 from Buenaventura Reserve, El Oro province; ( b ) Ninia guytudori sp. nov. from Santa Lucia Cloud Forest Reserve, Pichincha province. Photos by Jose Vieira. Description of holotype. Subadult female, 218 mm TL; 35 mm CL; 183 mm SVL; CL/SVL ratio 0.19; head distinct from body; HL 11.4 mm; HW 6.6 mm; rostral wider than high; internasals wider than long (1.2 x 0.6 mm); internasal suture 0.6 mm; prefrontals longer than internasals, as wide as long (1.9 x 1.9 mm; suture 1.9 mm); frontal U-shaped and as long as wide (2.6 x 2.6 mm); parietals longer than wide (4.1 x 2.2 mm); interparietal suture 2.7 mm; supraoculars 1/1, each longer than wide (1.2 x 0.8 mm), entering orbit and contacting postocular; nasal scales 2/2 where anterior nasal scale contacts internasal, rostral, first supralabial, and posterior nasal in contact with loreal, prefrontal, internasal, first and second supralabials; loreal single, longer than high (1.7 x 1.1 mm), entering orbit and in contact with 2nd and 3rd supralabials; postoculars 2/2; temporal formulae 1+2, anterior temporal scale 1.4 x longer than lower posterior temporal; anterior temporal in contact with 5th and 6th supralabials; supralabials 7/8; 3rd-4th or 4th and 5th entering orbit, 5th in contact with postocular; infralabials 7/8, 1st-4th/1st-5th in contact with two pairs of chin shields; dorsal scales in 19/19/19 rows, keeled, strongly striated, lacking apical pits; ventrals 138; divided subcaudals 44; cloacal plate undivided. Natural history. Specimens of Ninia guytudori sp. nov. have been found active at night on leaf-litter in old-growth cloud forest. During the daytime, they have been found hidden under rotten logs. When threatened, individuals flatten the body and tail (Fig. 8b ). Figure 8. Dorsal views of some specimens of Ninia from western Ecuador in life: ( a ) N. schmidti comb. nov. SCA 1446 from Buenaventura Reserve, El Oro province; ( b ) Ninia guytudori sp. nov. from Santa Lucia Cloud Forest Reserve, Pichincha province. Photos by Jose Vieira. Distribution. Ninia guytudori sp. nov. is endemic to an estimated area of 3,432 km2 along the Pacific slopes of the Andes in northwestern Ecuador. The species is known from 11 localities (listed in Suppl. material 3) and has been recorded at elevations 1190-1676 m above sea level (Fig. 2 ). Etymology. The specific epithet guytudori is a patronym honoring Guy Tudor, an all-around naturalist and scientific illustrator with a deep fondness for birds and all animals, in recognition of the impact he has had on the conservation of South America's birds through his artistry. For many years, Tudor and Bob Ridgely partnered in the preparation of numerous well-regarded volumes on the Neotropical avifauna. Conservation status. We consider Ninia guytudori sp. nov. to be included in the Near Threatened conservation category following the IUCN criteria ( IUCN 2012 ), because the species has been recorded in more than 10 localities (listed in Suppl. material 3) and it is distributed over an area which retains the majority (~53%) of its forest cover ( MAE 2012 ). Therefore, the species is facing no major immediate extinction threats. However, some populations are likely to be declining due to deforestation by logging and large-scale mining, especially in the province Imbabura ( Guayasamin et al. 2019 ), where only two populations of the species are known.