Friday, October 21, 2016

False Coral Snake, Erythrolamprus aescapulii (Family Dipsaidae)

On Trinidad, this species is known from a single specimen collected in Trinidad’s Arima Valley. Size: 640 mm SVL; 728 TL; tail 13.7% SVL. Identification: This snake is a coral snake mimic. Bands of red, white and black encircle the body in the sequence red-black-cream-black-red. Rostral visible from above; nasal divided; one preocular, loreal small and single; two postoculars; seven upper labials; nine lower labials; ventrals 198; cloacal plate divided; 41 paired subcaudals. Dorsal scales smooth and in 15 rows. Similar Species: The small coral snake lacks a loreal, and has single black bands. It can be readily distinguished from the large coral snake by the presence of a loreal scale, the narrow paired black bands (the large coral snake has wide black bands in triads). It can be distinguished from Jan’s False Coral Snake by its shorter tail (less than 50 subcaudals in aesculapii) and the posterior border of the rostral does not extend beyond the front edge of the nostril (it does so in bizona). Distribution: Widespread Trinidad, Venezuela, Colombia, and the Guianas southward to Brazil, Bolivia, Peru, Colombia, Ecuador, and Argentina. Habitat: A snake of primary forest that spends much of its time underground. The single Trinidad specimen from the Arima Valley is from wet, primary forest, transitional between seasonal and lower montane rainforest, above a stream. Natural History: Crepuscular, but may be active any time. Diet: other snakes including the three-lined snake, coral snakes, and the black headed snake; it may also eat synbranchid eels. Note: currently several subspecies are recognized, with E. a. aesculapii being the taxon present on Trinidad.

False Coral Snake, Erythrolamprus bizona (Family Dipsadidae)

Size: 1.5 meters. A tricolored snake which mimics a coral snake. Known from Trinidad on the basis of a single, now lost, specimen. Rostral visible from above; nasal divided; one preocular, loreal small and single; two postoculars; seven upper labials; nine lower labials; ventrals 178−204; cloacal plate divided; 51−62 paired subcaudals. Dorsal scales smooth and in 15 rows. It has been traditionally separated from E. aesculapii by the number of subcaudal scales; E. bizona has more than 45 subcaudals (longer tail), and E. aesculapii fewer than 45 subcaudals; but it can also be separated from E. aesculapii by the fact that the posterior border of the rostral extends beyond the front edge of the nostril; the posterior border of the rostral does not extend beyond the nasal in this species. It occurs from Nicaragua, southward through Central America to Panama and Colombia and eastward into Venezuela, and Trinidad. A fossorial, leaf litter dwelling snake that is poorly known, probably spending much of its time below ground.

Helminthophis flavoterminatus (Family Anomalepididae)

Size: 140 mm SVL; tail 4 mm, 2.8% of SVL. The yellow head, 18 scale rows around the body, and the absence of stripes on the body will distinguish it from all other Trinidad snakes. Rostral visible from above; nasal scale single; one preocular; two postoculars; one supraocular; suboculars absent; three upper labials; one lower labial. Each head plate covered with numerous tubercles. Longitudinal scale count about 401, subcaudals number 12−13. Dorsum and venter brown; head and chin are yellow; a yellow spot on throat on scales six seven; anal region and six medial, preanal scales are yellow, as well as several of the subcaudals. Similar species: In overall color it is similar to Typhlops brongersmianus, but is much more slender in body build. Diameter at midbody of this species 2 mm (total length/midbody width = 1.4%), while midbody widths for Typhlops brongersmianus range between 3.4−12.9 mm (total length/midbody width = 3.21−5.1 %, x= 4.05%). Habitat: The specimen came from an area in the Northern Range that may be best regarded as disturbed lower montane rainforest. Biology: Like other scolecophidian snakes it most likely feeds on ant and termite eggs, larvae, and pupae. The single known specimen is an adult female containing one egg.

Water Coral, Hydrops triangularis (Family Dipsadidae)

Other common names: Red Sided Water Snake; Water Snake.
Size: 963 mm TL. Most individuals are smaller.
The only Trinidad snake with 15 rows of smooth dorsal scales, a loreal (distinguishing it from true coral snakes), and red to dark purple rings that completely encircling the body. Rostral visible from above; nasals divided; loreal single and larger than eye; one preocular fused with the loreal; the internasal scale separates the preocular-loreal from the nasal; one or two (usually two) postoculars; eight upper labials; eight lower labials; 170−176 ventrals; cloacal plate divided; 45−47 subcaudals. Smooth dorsal scales in 15 rows at mid-body with no reduction posteriorly. Dorsum purple-brown with red-brown on sides; off-white on venter. Dorsal annuli number 48−68 on body, most circle the body, some incomplete on mid-dorsum or mid-venter. Head dark purple-brown, each labial with a light center.
Probably most easily confused with the Water Mapepire, but it has 19 scale rows at mid-body, and Linne’s Water Snake which is mostly black or green as an adult but has a banded pattern when young, it has 17 rows of dorsal scales that are reduced to 15 rows near the posterior body.
The species has an Amazonian-Guyana distribution. It is widespread on Trinidad, but is unknown from Tobago. This is probably the most aquatic snake on Trinidad, with the possible exception of the Anaconda. The Water Coral uses swamps, slow rivers, ponds, and flooded rice fields. Reports suggest they prefer water that is relatively shallow and shaded. Nocturnal, but may be active during the day. Diet includes synbranchid eels and other elongated freshwater fishes. The average clutch size is about 15, with a range of 8 to 34.

Blunt-headed Tree Snake, Imantodes cenchoa (Family Dipsidadae)

Size: 1050 mm SVL, tail 450 mm; tail is about 43% of the body length. A very slender brown and tan snake, with smooth dorsal scales in 17 rows; the vertebral row is enlarged. The head is blunt; the eyes are huge, with a vertical pupil. The 17 dorsal scale rows, large eyes, and the presence of a mental groove will distinguish it from Dipsas trinitatis, the species that it will most easily be confused with. Rostral barely visible from above; nasal divided; loreal small; preocular single; two or three postoculars; seven to nine upper labials; 9−11 lower labials; ventrals 234−258; cloacal plate divided; 150−174 paired subcaudals. A widespread species, ranging from Mexico to Paraguay and Bolivia; it is present on both Trinidad and Tobago. This is a highly arboreal snake of the forest canopy and understory. Nocturnal.

Bushmaster, Lachesis muta (Family Viperidae)

Other common names: Pineapple snake, mapepire zanana. Size: 2 m, maximum TL 3353 m; at hatching 350−380 mm. Triangular rostral not visible from above; nostrils very anterior, open laterally in a divided nasal; heat-sensing pits located in the second labial scale which is fused with the prelacunal scale; preocular large and separated from nasal by a small loreal; 2–3 very small postoculars; two pairs of enlarged scales above the nasals; remaining scales on crown small and somewhat granular, except for large supraoculars; subocular elongate in Trinidad specimens, but divided in specimens from elsewhere in the range; between subocular and upper labials four rows of small scales; upper labials 9–10, lower labials 12–17; first pair of lower labials form the mental groove with the single pair of enlarged chin shields; dorsal scales in first row are smooth and ovate, scales in rows 2–6 are smooth to weakly keeled; and scales closest to midline are lanceolate, strongly keeled with raised conical keels. Dorsal scale rows at midbody 27 in one Trinidad specimen when small abnormal scales are omitted from the count. Ventrals 200–230, cloacal plate single, 32–50 paired subcaudals (but some may be single). Crown of head uniform or slightly spotted with dark blotches; dark postocular stripe extending above and past the comer of mouth; body with 25 transverse blotches that may fuse on the midline; blotches narrow toward ventrals and expand toward midline; dark pigment predominates on tail and is separated by narrow tan or orange-brown rings. Large triangular head distinct from neck, dorsum usually yellow with darker triangular markings; scales with conical keels given the skin a rough appearance; 9 or 10 upper labials and distal subcaudals divided into five rows will distinguish this snake from the Trinidad Bothrops. Occurs in greater Amazonia and Trinidad; widespread on Trinidad, but limited by human activity. Habitat: Forest dweller often associated with agouti, paca, or armadillo burrows. Nocturnal. Often sits in ambush for long periods of time, along fallen trees or tree buttresses. When not hunting or searching for mates these snakes are likely spending most of their time underground in the burrows of the mammals noted above. Diet mostly mammals. Juvenile bushmasters have a yellow tail tip suggesting that they may use caudal luring to obtain prey, but this has not yet been documented. Bushmasters are the only documented New World pitviper to lay eggs, although anecdotal evidence suggests there is another species that does so. Egg laying was first reported in bushmasters from Trinidad by Raymond Ditmars. Captive female bushmasters that lay eggs attend them by coiling around the clutch. Clutches of 6−12 eggs reported for this species with an incubation period of 60−69 days. Captive have been reported to live for more than 16 years, but Trinidad specimens have the reputation for not living long after capture and pentastomid parasites (lungworms) are suspected of being the cause of death.

Cat-eyed Snake, Leptodeira annulata ashmeadi (Family Dipsadidae)

Other common names: Mapepire, mapepire valsyn, annulated night snake, banded night snake, false mapepire, cat eyed night snake, chunkhead, garden snake, night snake.
Size: 1065 mm SVL, 435 mm tail; but most specimens are less than 500 mm in total length.  The only Trinidad and Tobago snake with 19 (or 21) rows of smooth scales that are reduced to 15 rows near the vent, vertebral row slightly enlarged; a vertical pupil; a tan or brown dorsum with black blotches (may number 36–38) along the back that may fuse to form a stripe, or multiple stripes along the vertebral line. Rostral visible from above; nasal divided; loreal single; one or two preoculars; one or two postoculars; seven to eight upper labials; 8−10 lower labials; ventrals 177−180; cloacal plate divided; 76−90  paired subcaudals. A habitat generalist, using forests, savanna, agricultural areas, and urban gardens. Nocturnal. Diet: Often found in the vicinity of frog choruses, where it will prey on adult frogs, frog eggs, and larvae. Females have been reported to lay 3−11 eggs in arboreal situations such as cavities in bamboo stems and termitaria, as well as terrestrial sites such as leaf cutter ant nests; females have been found carrying eggs in July. Like many rear fanged snakes this species has been reported to cause mild cases of envenomation in humans. 

Leptophis haileyi (Family Colubridae)

 Size: 857 mm SVL, TL 1.4 m.  The only Trinidad and Tobago Leptophis species to have a subacuminate snout in profile, the rostral barely visible from above, and the primary temporal in contact with three or four upper labials. Tobago specimens of L. coeruleodorsus have two upper labials contacting the primary temporal with the last upper labial excluded from primary temporal contact. In L. haileyi, the last upper labial makes narrow contact with the primary temporal.  Leptophis haileyi has longitudinal dorsolateral stripes on the anterior body scale rows 2–4; nine upper labials, 2–3–4 at the loreal-prefrontal shield, 5–6 in the orbit; 5/4 lower labials at the first pair of chin shields. Similar species: L. coeruleodorsus on Tobago has eight upper labials with 2–3 contacting the loreal-prefrontal shield, 4+5 in the orbit, and two upper labials contacting the primary temporal. This species can also be distinguished from L. coeruleodorsus by its domed snout (prefrontal –internasal area), its relatively high ventral count (173), and proportionally shorter tail. The male holotype has a tail:SVL ratio (0.64) and a subcaudal count (166) that fall within the range of L. coeruleodorsus females. Distribution: Roxborough River drainage of Tobago.  

Erythrolamprus cobellus (Family Dipsadidae)

Other common names: Mapepiri mangue, mangrove snake, mangrove mapepire. Size: 572 mm SVL, tail 222 mm.  A mostly black, semi-aquatic snake with a black-brown dorsum with white flecks, the belly has transverse bands. Dorsal scales smooth in 17 rows at mid-body reduced to 15 near the vent. Rostral visible from above; nasal divided; one preocular, loreal small and single; two postoculars; seven to nine upper labials; 8−11 lower labials; ventrals 130−147; cloacal plate divided; 37−56 paired subcaudals. All other Trinidad and Tobago Erythrolamprus have longitudinal stripes; transverse bands, or dorsal blotches. Because the dorsum may be almost entirely black, it could be confused with Clelia (19 scale rows and more than 200 ventrals) or Spilotes (16 or 18 scale rows, mostly keeled, and more than 200 ventrals). Widespread in northern South America - Colombia, Venezuela, Trinidad, the Guianas, Brazil, and Ecuador. Semi-aquatic in fresh and brackish water; present in mangroves swamps, herbaceous swamps, rice paddies, associated streams. Regularly travels overland and may be seen on roads. Active late afternoon and after dark. Diet: includes a variety of small vertebrates. Reported to lay eggs in June, clutch sizes less than six eggs. 

Shaw's Black-backed Snake, Erythrolamprus melanotus nesos (Family Dipsadidae)

Other common names: Beh belle chemin (=beauty of the road), squirrel snake; on Tobago: doctor snake.
Size: 604 mm SVL, 150 mm tail. Rostral visible from above; nasal divided; one preocular, loreal small and single; two postoculars; seven to eight upper labials; seven to nine lower labials; ventrals 142−156; cloacal plate divided; 54−63 paired subcaudals. Dorsal scales smooth, contain one apical pit, and are in 17 rows that reduce to 15 posteriorly.  Similar Species: the only snake in Trinidad and Tobago with a broad black dorsal stripe five scales wide bordered with yellow or salmon on the sides; head usually olive-brown or black. Endemic to Trinidad and Tobago. A forest snake that is closely associated with streams and ponds, uses cacao plantations and other disturbed habitats. Diurnal. Diet includes small vertebrates, mostly frogs (Engystomops pustulosus, Pristimantis urichi) tadpoles, and lizards (Bachia trinitatis, Gonatodes vittatus). Clutches of 2−10 eggs have been reported between January and August.

Neotropical Racer, Mastigodryas boddaerti (Family Colubridae)

Size: 877 mm SVL, 1187 mm TL, can reach 1.4 m; hatchlings 250 mm. Dorsal scale rows 17 at mid-body, reduced to 15 posteriorly; each scale has a pair of apical pits, otherwise smooth. Rostral visible from above; nasals divide, nostril large; loreal rectangular; one preocular; two or three postoculars;  upper labials 8−10, lower labials 8−10; ventrals 179−196; divided cloacal plate; 106−124 divided subcaudals; eyes large. A lateral stripe on scale rows 4–5. Juveniles are red brown with about 72 white dorsal cross bands, each bordered with black. The colors change to olive green or olive brown with maturity. The combination of 17 rows of dorsal scales with apical pits, a loreal, a vertebral scale row that is not enlarged, and five lower labials in contact with the first chin shield, will separate the species from all other Trinidad and Tobago snakes, except for the two other species of Mastigodryas. The Tobago Racer, M. dunni, is restricted to that island and has an extra stripe on scale rows 1−2. The Yellow-necked Racer may be found (not confirmed) on both Trinidad and Tobago and potentially sharing habitat with this species and M. dunni and it has a stripe on the anterior body that spans scale rows 3−4−5.  A common, fast moving, ground dwelling, forest snake often in leaf litter but it will enter grassy areas at forest-edge and ponds. Diurnal. Diet includes insects, frogs, lizards, nestling birds, rodents, and reptile eggs. A study on a Brazilian population found lizards made up 74% of the diet, followed by mammals and frogs; it also reported female’s take a wider range of prey than males, and female feed when carrying eggs. Females deposit eggs in May. Other common names: Boddaert's tropical racer, grass machete, couesse grass snake.

Erythrolamprus zweifeli (Family Dipsadidae)

Size: 509 mm TL, maximum total length may approach 800 mm.  Rostral visible from above; divided nasal; single loreal; single preocular; two (occasionally one) postocular; seven to nine upper labials; 8–10 lower labials; 137–146 ventrals; divided anal plate; 61–80 paired subcaudals; dorsal scales are smooth, in 17 rows at midbody reduce to 15 posteriorly. Dorsum can be olive green with each scale edged with black or a uniform brown above; crown with a black blotch; black stripe posterior to the eye; tail with black stripe on each side, venter red-pink or cream with black checkering on some scutes. The two color morphs of this snake make it somewhat confusing: the “salt & pepper morph” is readily distinguished from all T&T snakes at a glance, and the brown –green morph may be confused with Leptodeira (19 dorsal scale rows) or Mastigodryas (170 or more ventrals), but this species has a red and black belly not found in either of these species. Trinidad Erythrolamprus well as other colubrid snakes. A forest and forest-edge snake; often in the vicinity of streams. Diurnal. Diet includes frogs (hylid frogs, Leptodactylus sp., Mannophryne trinitatis, Scinax rubra), lizards (Ameiva atrigularis), and small birds. When disturbed neck is flattened to form a small, narrow hood.

Tobago Racer, Mastigodryas dunni (Family Colubridae)

Size: 776 mm SVL, 881 mm TL, hatchlings 240 mm. Identification: Dorsal scale rows 17 at mid-body, reduced to 15 posteriorly; each scale has a pair of apical pits, otherwise smooth. Rostral visible from above; nasals divide, nostril large; loreal rectangular; one preocular; two or three postoculars;  upper labials 8-10, lower labials 8-10; ventrals 185−196; divided cloacal plate; 119−124 divided subcaudals; eyes exceptionally large. The dorsum is blue-gray, a light, indistinct  stripe present on scale rows 1-2, a more distinct stripe present on rows 4-5, laterally coloration becomes lighter, including light labials; the venter is white-pink with some blotches; the underside of the tail may be flecked with gray. It is likely that the juveniles are blotched with cross bands like M. boddaerti and that the colors change to an blue-gray with maturity. The combination of dorsal scales in 17 rows at mid body, scales with apical pits, a loreal, a vertebral scale row that is not enlarged, and five lower labials in contact with the first chin shield, and two lateral stripes one scale row 1–2 and a second on rows 4–5 should separate the species from all other Trinidad and Tobago snakes, except the other two species of Mastigodryas . The Tropical Racer, M. boddaerti is restricted to Trinidad, but the Yellow-necked Racer, M. amarali, is not confirmed from  the islands. The two may be distinguished by a stripe on the anterior body that spans scale rows 3−4−5 in the Yellow-necked Racer, and only rows 4-5 in this species. Known only from Tobago and Little Tobago Islands. A forest and forest-edge species. Diurnal. Diet probably similar to the Tropical Racer, but it has not been studied.

Ratonel, Pseudoboa neuwiedii (Family Dipsadidae)

Other common names: roulea, mapepire velour, ratonera, moon snake, brown snake.

Size: 870 mm SVL, 215 mm tail; 1085 mm TL. Rostral slightly upturned, visible from above; loreal single; one or two preoculars; two postoculars; eight upper labials; 6–8 lower labials; 195–201 ventrals; single cloacal plate; and 74–97 single subcaudals; dorsal scales smooth in 17 or 19 rows at midbody. Adult snakes are red-brown or pink-brown with a darker brown-black head; Young red or pink above with a dark head and a cream collar that fades with age. Each dorsal scale with a dark spot enlarging with age; venter uniform cream. Adults are a uniform salmon color with a dark head. Juveniles have been confused with its close relative Clelia clelia; both species have hatchlings and juveniles that are pink-red to bright red with a black head, light colored band, followed by a black band.  However, the uniquely shaped upturned rostral and single subcaudals, will separate Pseudoboa from Clelia. Oxyrhopus petolarius, may be banded or a uniform black, but it lacks the up-turned rostral and has divided subcaudals. A widespread species, from Panama and Colombia eastward to Suriname, and south to Brazil; widely distributed on both Trinidad and Tobago.  Forest, savanna; common in most habitats, including: agricultural areas, gardens, yards, and plantations. Crepuscular, nocturnal. Diet includes: any appropriately sized vertebrate killed with a combination of constriction and venom; Ameiva atrigularis seems to be a frequently taken prey species; and they have been suggested to be nest predators. May actively forage on the ground or hunt from ambush in low vegetation.  Clutches of 3–9 eggs laid in leaf cutting ant nests in July, September, January, and February. Venom: Anecdotal evidence suggests this snake’s venom may be quite toxic to both mammals and reptiles; it usually does not attempt to bite when picked-up but it should be handled with care.

Cutlah, Phrynoax polylepis (Family Colubridae)

Size: 870 mm SVL, 1235 mm TL, may exceed 2135 mm TL, hatchlings 255 mm. Identification:  Adults a uniform olive green with some, but not all scales keeled in 21 or 23 rows at mid-body reduced to 15 rows posteriorly, and upper labials 4-5-6 in the orbit. Young (<495 mm TL) have crescent-shaped blotches that form cross bands on the dorsum.  Rostral visible from above; nasals single; loreal single; one preocular; two postoculars;  seven upper labials,10−11 lower labials; ventrals 193−203; cloacal single; divided subcaudals 156−181 in males 125−126  in females; dorsal scales smooth with apical pits. Perhaps most easily confused with snakes of the genus Chironius which have 10 or 12 dorsal scales at mid-body; and with Spilotes sulphureus which has a black and yellow dorsum and upper labials 4−5 on the orbit. Ranges from Columbia to the Guianas, including Trinidad, and southward into the Amazon basin. An arboreal snake of forest and forest-edge habitats. Diurnal and crepuscular. Diet: Actively forages for nestling birds and eggs; probably a specialized nest predator; but will also prey on lizards and mammals. Defense: Cryptic behavior includes kinking its body into a shape that resembles a liana to avoid detection; behavior includes inflate its forebody, gape its mouth, actively striking, and vibrating its tail when disturbed. 

Slug-eating Snake, Sibon nebulata (Family Dipsadidae)

Other common names: Mapepire corde violin, fiddle string mapepire; cloud snake, cloudy snake.

Size: 440 mm SVL; 158 mm tail; total length about 1 meter. Identification: A medium sized, gray to brown blotched snake with a mottled pattern; body slightly compressed, slender forebody, wide head, large eyes. Smooth dorsal scales in 15 rows, not reduced posteriorly; the vertebral row is slightly enlarged (scales about 1.5 times wider than lateral scales). Rostral barely visible from above, nasals divided, loreal contacts the orbit; preocular usually absent; postoculars two; upper labials 7−8, 4−5 or 5−6 in orbit, 2−3−4 usually contact the loreal; lower labials 8-10; ventrals 169−182 in Trinidad and Tobago specimens, not sexual dimorphic, subcaudals in males 89−113, in females 84−90. Three pairs of chin shields, the first pair in contact with five or six lower labials.  The only Trinidad and Tobago snake with 15 rows of smooth scales rows at midbody, a slightly enlarged row of vertebral scales, and a mental groove. The dorsum is usually gray with 36−41 brown to black blotches. Most easily confused with Dipsas trinitatis which lacks the mental groove; and with Imantodes cenchoa, an extremely slender snake with 17 scale rows at mid-body. This is a widespread species, ranging from Veracruz and Nayarit, Mexico, to Brazil and Ecuador. S. n. nebulata occurs in the northern portion of this range, including Trinidad, Tobago and the Bocas. Habitat: Forests and forest edge; may be found on the ground, but mostly arboreal, climbing several meters above in vegetation; frequently found along streams. It will also use second forest and agricultural areas.  Biology: Nocturnal. May spend daylight hours coiled in epiphytic plants or on the ground in leaf litter. Diet: snails and slugs; this snake is not as specialized as Dipsas for feeding on snails, but it does have elongated maxillary teeth directed medially in the horizontally plane, a character associated with gastropod predation. This is perhaps the most frequently encountered snake during the wet season.  Reproduction: Females lay 3−9 eggs from May through September. Predation by the crab Eudaniela garmani has been reported.