Sibon marleyae, Arteaga & Batista, 2023
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publication ID |
https://dx.doi.org/10.3897/zookeys.1143.93601 |
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publication LSID |
lsid:zoobank.org:pub:8889CB19-B159-4D07-881C-7A87B033BCF3 |
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persistent identifier |
https://treatment.plazi.org/id/86EE4400-A3F1-4414-AB46-5E391D2AED24 |
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taxon LSID |
lsid:zoobank.org:act:86EE4400-A3F1-4414-AB46-5E391D2AED24 |
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treatment provided by |
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scientific name |
Sibon marleyae |
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sp. nov. |
Sibon marleyae sp. nov.
Figs 2g-i View Figure 2 , 4c View Figure 4 , 5d View Figure 5 , 8 Proposed standard English name: Marley’s Snail-eating Snake Proposed standard Spanish name: Culebra caracolera de Marley View Figure 8
Type material.
Holotype: ZSFQ 5065 (Figs 2g View Figure 2 , 5d View Figure 5 , 8 View Figure 8 ), adult male collected by Amanda Quezada, Eric Osterman, and Regdy Vera in December 2021 at Verdecanandé, Esmeraldas Province, Ecuador (0.52395, -79.01233; 344 m a.s.l.).
Paratypes: MZUTI 3034, adult male collected by Jaime Culebras on 22 July 2013 at Reserva Itapoa, Esmeraldas Province, Ecuador (0.51307, -79.13401; 321 m a.s.l.). ICN 10834, adult male collected at San José del Palmar, Chocó department, Colombia (4.96841, -76.22751; 1338 m a.s.l.). ZSFQ 5069, adult male collected by Jose Vieira, Daniela Franco, and Alex Mora on 4 December 2019 at Reserva Biológica Canandé, Esmeraldas Province, Ecuador (0.49531, -79.17832; 560 m a.s.l.). ZSFQ 5067, adult female collected by Jose Vieira, Frank Pichardo, and Matteo Espinosa at Durango, Esmeraldas Province, Ecuador (1.04161, -78.62658; 245 m a.s.l.). CPZ-UV 04567, adult female collected by Andrés Gómez Figueroa at Tamboral, Valle del Cauca department, Colombia. CZI-R009, adult female collected by Santiago Orozco on 9 September 2018 at Campamento Yatacué, Valle del Cauca department, Colombia (3.57472, -76.87777; 598 m a.s.l.). CZI-R051, adult female collected by Santiago Orozco on 16 June 2019 at Represa Murrapal, Valle del Cauca department, Colombia (3.55283, -76.98077; 321 m a.s.l.).
Diagnosis.
Sibon marleyae sp. nov. is placed in the genus Sibon based on phylogenetic evidence (Fig. 1a View Figure 1 ) and on having the penultimate supralabial conspicuously higher than all other supralabials. The species is diagnosed based on the following combination of characters: (1) 15/15/15 smooth dorsals with enlarged vertebral row (up to 2 × as wide as adjacent rows); (2) loreal and prefrontal in contact with orbit; (3) 7-8 supralabials with, usually, 4th, 5th, and occasionally 6th contacting orbit; (4) usually 8-9 infralabials with 2nd-6th in contact with chinshields, first pair of infralabials not in contact behind symphysial due to presence of two postmentals; (5) 186-204 ventrals in males, 176-193 in females; (6) 130-143 divided subcaudals in males, 109-128 in females; (7) dorsal background color olive to yellow with maroon (black in juveniles) bands (1-2 dorsal scales long mid-dorsally and 3-5 dorsal scales long on the lower flanks) and a reddish tint along the vertebral line (Figs 2g-i View Figure 2 , 4c View Figure 4 ), ventral surfaces white with encroachment from the dorsal maroon blotches (Fig. 8b View Figure 8 ), dorsal aspect of head composed of blackish symmetrical markings on a red background color (Fig. 5d View Figure 5 ), throat white with broad brownish blotches, iris rich reddish brown; (8) 308-464 mm SVL in males, 329-368 mm in females; (9) 167-233 mm TL in males, 175-183 mm in females.
Comparisons.
Sibon marleyae sp. nov. is compared to other species of Sibon previously subsumed under S. annulatus sensu lato (differences summarized in Table 2 View Table 2 ). From S. annulatus sensu stricto, the new species differs in having maroon bands usually broken along vertebral line rather than bands extending over the entire dorsal and lateral surfaces, a bright reddish coloration along the mid-dorsum and on the top of the head (Figs 4c View Figure 4 , 5d View Figure 5 , 8a View Figure 8 ), and a higher number of ventral scales in males and females (Table 2 View Table 2 ). Sibon marleyae sp. nov. differs from S. canopy sp. nov. by having two postmental scales (instead of only one), a higher number of ventrals in males and females, a pattern of symmetrical (rather than irregular and asymmetrical) markings on the dorsal surface of the head (Fig. 5 View Figure 5 ), and by lacking maroon spots enclosed in the dorsal olive interspaces (Figs 2g-i View Figure 2 , 4c View Figure 4 ). Sibon marleyae sp. nov. differs from S. irmelindicaprioae sp. nov. primarily by having a pattern of broad blackish markings on the head instead of a finely variegated pattern and by having a higher number of ventrals and subcaudals in both males and females (Table 2 View Table 2 ).
Description of holotype.
Adult male, SVL 335 mm, tail length 167 mm (49.8% SVL); head length 12.8 mm (3.8% SVL) from tip of snout to angle of jaw; head width 7.6 mm (59% head length) taken at broadest point; snout-orbit distance 3.1 mm; head distinct from neck; snout short, blunt in dorsal outline and rounded in profile; rostral 2.1 mm wide, higher than broad; internasals 1.3 mm wide, broader than long; prefrontals 1.6 mm wide, longer than broad, entering orbit; supraocular 2.8 mm long, longer than broad; frontal 2.9 mm long, pentagonal and with a straight anterior border, in contact with prefrontals, supraoculars, and parietals; parietals 4.3 mm long, longer than broad; nasal divided, in contact with two supralabials, loreal, prefrontal, internasal, and rostral; loreal 1.2 mm long, longer than high, entering the orbit; eye diameter 2.9 mm; pupil semi-elliptical; no preocular; two postoculars; temporals 1+2; seven supralabials with 4th and 5th contacting orbit; symphysial precluded from contacting chinshields by the presence of two small postmentals; eight infralabials with 2nd-6th contacting chinshields on the right side, nine infralabials with 2nd-7th contacting chinshields on the left side; two pairs of chinshields longer than wide; dorsal scales in 15/15/15 rows, smooth, without apical pits; 204 ventrals; 132 divided subcaudals; cloacal plate entire.
Natural history.
Specimens of Sibon marleyae sp. nov. have been found at night foraging on shrubs and trees 1-6 m above the ground in old-growth evergreen lowland/foothill forests, particularly along streams and small rivers. Snakes of this species are docile and never attempt to bite. When threatened, individuals may hide the head among body coils and produce a musky and distasteful odor. One female (Fig. 2h View Figure 2 ) from the type locality laid two eggs in a terrarium. After an incubation period of 80 days, one of the eggs hatched (Fig. 2i View Figure 2 ).
Distribution.
Sibon marleyae sp. nov. is known from 17 localities (listed in Suppl. material 2) along the Chocoan lowlands and adjacent foothills of the Andes in Ecuador and Colombia, with populations on the coastal mountain ranges Mache-Chindul and Cerro Pata de Pájaro in Ecuador. The species has been recorded at elevations 131-1338 m above sea level (Fig. 6 View Figure 6 ).
Etymology.
The specific epithet Sibon marleyae is a patronym honoring a young nature lover, Marley Sheth, the 11-year old daughter of Brian and Adria Sheth, both long-time supporters of biodiversity conservation around the world.
Conservation status.
We consider Sibon marleyae sp. nov. to be included in the Least Concern category following IUCN Red List criteria ( IUCN 2001) because the species is distributed over a region of the Chocó biome that holds large areas of continuous unspoiled forest. Based on the species distribution model presented in Fig. 6 View Figure 6 in combination with maps of vegetation cover of Colombia ( IDEAM 2014) and Ecuador ( MAE 2012), we estimate that more than half (~ 55%) of the species’ forest habitat is still standing. Unfortunately, vast areas of the Chocó rainforest in western Ecuador have already been converted to pastures ( Myers et al. 2000). However, S. marleyae sp. nov. occurs over an area greater than 25,000 km2 and is presumably not declining fast enough to qualify for a threatened category.
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