Corresponding author: A. A. Thasun Amarasinghe (
Guest academic editor: Johannes Penner
The description of
The colubrid genus
Museum acronyms follow
The following characters were measured with a digital caliper (±0.1 mm) on the left side of the body for symmetrical characters: eye diameter (ED, horizontal diameter of eye); eye–nostril length (EN, distance between anterior most point of eye and middle of nostril); snout length (ES, distance between anterior most point of eye and snout); nostril diameter (ND, horizontal diameter of nostril); internarial distance (IN, least distance between nostrils); mandible–posterior eye distance (MPE, distance between posterior edge of mandible and posterior most edge of eye); interorbital width (IO, least distance between upper margins of orbits); head length (HL, distance between posterior edge of mandible and tip of snout); head width (HW, maximum width of head); snout–vent length (SVL, measured from tip of snout to anterior margin of vent); tail length (TAL, measured from anterior margin of vent to tail tip). Meristic characters were taken as follows: supralabials and infralabials (SUP and INF, first labial scale to last labial scale bordering gape); costal scales (COS, counted around the body from one side of ventrals to the other in three positions, on one head length behind neck, at mid body and at one ventral scale prior to preanal); when counting the number of ventral scales (MVS), we scored specimens according to method described by Dowling (1951). We counted subcaudal scales (SUB) from first postcloacal scale to the scale before the tip of the tail.
Standard morphometric and meristic data of the two syntypes are presented in Table
Morphometric and meristic characters of
Character | MNHN 3238 Lectotype (female) | MNHN 3239 Paralectotype (male) |
---|---|---|
snout–vent length (SVL) | 254.0 | 150.0 |
tail length (TAL) | 35.0 | 27.0 |
head length (HL) | 10.8 | 8.1 |
head width (HW) | 4.7 | 4.1 |
internarial distance (IN) | 2.1 | 1.5 |
interorbital width (IO) | 3.7 | 3.3 |
eye–nostril length (EN) | 1.9 | 1.7 |
eye–snout length (ES) | 3.4 | 2.7 |
mandible–posterior eye distance (MPE) | 5.8 | 4.1 |
nostril diameter (ND) | 0.3 | 0.4 |
eye diameter (ED) | 1.7 | 1.4 |
costals (COS) | 17-15-15 | 17-15-15 |
subcaudals (SUB) | 28 | 36 |
ventrals (MVS) | 150 | 138 |
supralabials (SUP) | 7 (3, 4 touch eye) | 7 (3, 4 touch eye) |
infralabials (INF) | 8 | 8 |
(here designated). MNHN 3238, adult female collected from the Philippines (mistakenly so in the original description) [from Java (also in error) according to the museum registry] by an unknown collector [by Bosc (in error) according to the museum registry].
MNHN 3239, sub adult male collected at ‘Ceylan’ [= Sri Lanka] by Leschenault. This specimen was previously erroneously considered as the holotype by
Some sexual dimorphic characters of
sex | SVL (mm) | TAL (mm) | VEN | SUB |
---|---|---|---|---|
male | 152.0–227.0 ( |
25.0–38.0 ( |
135–151 ( |
30–42 ( |
female | 156.5–295.0 ( |
20.0–42.0 ( |
145–159 ( |
24–29 ( |
Characters. Ventral side with three series of points forming stripes.
This species is mostly characteristic, as its specific name, by having three black stripes along the ventral side, which are made up of a series of points, meeting together. The two stripes outside the ventral plates form a continuous line up to the ventral surface of the tail, but the central one is made up of distinct points in the centre of the ventral plates. These points are quite large, round and wide posteriorly, and are as notched at the front; the median stripe does not prolongate onto the ventral side of the tail.
Dorsal coloration grey, speckled with lines or with small elongated spots irregularly placed; however, around the anterior third of the body and laterally, three of those spots appear enlarged with increased width, having a circular border. The spots are constricted centrally and have white borders. The posterior section of the jaws has a large, oblique patch along the neck posteriorly where it forms a tip pointing in the opposite direction to the characteristic collar of the first species [note from the translator:
Dorsal scales are very smooth, and are close to each other; they are slightly overlapping, like roof tiles, mostly around the tail area, and in this respect, very skink-like in appearance.
Rostral plate is notched, and crescent shaped; other plates covering the head are large and clearly distinct as in colubrids.
We were only able to examine one well preserved specimen, having no clues as to the origin of the specimen [the Philippines] and the name ‘
Another specimen, younger and obviously added much later, had a median stripe made up of numerous spots which were less distinct, was collected from Ceylan by Mr. Leschenault. This specimen bears all the characters previously described: the large, brown, post-maxillary mark set posteriorly on the neck forming a croissant shape; with a laterally set, black mark extending onto the anterior third of the body.
We counted 15 scale rows on that specimen, 155 ventrals and 25 subcaudals.
Total length was 180 cm [sic]; among them 155 for SVL and 25 for the tail.
Adult female, SVL 254 mm; tail length 35 mm; head elongate (HL 4.3% of SVL), twice as long as wide (HW 43.5% of HL), slightly flattened, distinct from neck; snout elongate (ES 31.5% of HL), moderate, blunt in dorsal view, rounded in lateral profile, forming an oval shape, rather depressed.
Rostral shield large, hemispherical, distinctly visible from above, pointed posteriorly; interorbital width broad (IO 78.7% of HW); internasals semicircular; nostrils rather large; nasals completely divided by nostrils into two scales unequal in size; anterior nasal larger, in anterior contact with rostral, internasal dorsally, 1st SUP ventrally; posterior nasal in contact with internasal and prefrontal dorsally, loreal posteriorly, 1st and 2nd SUP ventrally; prefrontal rather large, broader than long, and subhexagonal; frontal large, subhexagonal, elongate posteriorly and longer than its width; supraoculars narrow, elongated, subrectangular, posteriorly wider; parietals large, butterfly wing-like in shape, bordered by supraoculars, frontal, upper postoculars anteriorly, anterior and upper posterior temporals, and six dorso-nuchal scales posteriorly; loreal large, slightly elongated, subrectangular, in contact with prefrontal dorsally and preoculars posteriorly, ventrally only touching the 2nd SUP; one preocular (both sides), vertically elongated, subrectangular, in contact with prefrontal and loreal anteriorly, supraocular dorsally, and 3rd SUP ventrally; eye moderate (ED 15.7% of HL), elliptical, nearly a half of the size of snout length (ED 50% of ES), pupil rounded; two postoculars, upper postocular smaller, quadrangular, contact with supraocular and parietal broad, in narrow contact with anterior temporal; lower postocular crescent in contact with 4th and 5th SUP ventrally, anterior temporal posteriorly; temporals 1+2, elongated, hexagonal; anterior temporal larger and longer than posterior temporals, in contact with parietal dorsally, 5th and 6th SUP ventrally; posterior temporals smaller, lower one in contact with 6th and 7th supralabials ventrally.
Supralabials 7 (on both sides), 4th–7th larger in size; 1st SUP in contact with rostral anteriorly, nasals dorsally, 2nd supralabial with posterior nasal and loreal dorsally, 3rd SUP with preocular and orbit dorsally, 4th SUP with orbit and the lower postocular dorsally, 5th SUP with lower postocular and anterior temporal dorsally, 6th supralabial with anterior temporal and lower posterior temporal dorsally, and 7th SUP with lower posterior temporal dorsally and body scales posteriorly.
Mental of moderate size, triangular; first infralabial pair larger than mental plate and in broad contact with each other, in contact with anterior chin shield posteriorly; eight infralabials, 1st–5th in contact with first chin shield, 5th infralabial largest in size in narrow contact with the anterior chin shield and in broader contact with the posterior chin shield; 6th–8th infralabials in contact with gular scales; two larger anterior chin shields, and two smaller posterior chinshields all in broad contact; posterior chin shield bordered posteriorly by six gular scales.
Body robust, elongate and sub cylindrical; costal scales in 17-15-15 rows, all smooth and bluntly pointed; 150 ventral scales; anal plate divided. Tail comparatively short (TL 13.8% of SVL), robust and thick; subcaudals 28, divided.
The values of NMSL 5161 (when different) included within parenthesis. Sub adult male (adult male), SVL 150.0 (183.3) mm; head elongate, HL 5.4 (5.6)% of SVL, twice as long as wide, HW 50.6 (53.9)% of HL, slightly flattened, distinct from neck; snout elongate, ES 31.4 (33.3)% of HL, moderate, blunt in dorsal view, rounded in lateral profile, forming an oval shape, rather depressed.
Rostral shield large, hemispherical, distinctly visible from above, pointed posteriorly; interorbital width broader, IO 80.5% of HW; internasals semicircular; nostrils rather large; nasals divided into two scales unequal in size; anterior nasal larger, in contact with the rostral plate anteriorly, internasal dorsally, 1st SUP ventrally; posterior nasal in contact with internasal and prefrontal dorsally, loreal posteriorly, 1st and 2nd SUP ventrally; prefrontal rather large, broad, and subhexagonal; frontal large, subhexagonal, elongate posteriorly and longer than its width; supraoculars narrow, elongated, subrectangular, posteriorly wider; parietals large, butterfly-like in shape, bordered by supraoculars, frontal, upper postoculars anteriorly, anterior and upper posterior temporals, and six dorso-nuchal scales posteriorly; loreal large, slightly elongated, subrectangular, in contact with prefrontal dorsally, preoculars posteriorly, posterior nasal anteriorly, ventrally just meets the 2nd SUP; one preocular in both sides, vertically elongated, subrectangular, in contact with prefrontal and loreal anteriorly, supraocular dorsally, and 3rd SUP ventrally; eye moderate, ED 17.3 (17.6)% of HL, elliptical, nearly a quarter of the snout length, ED 51.9 (56.2)% of ES, pupil rounded; two postoculars, upper postocular smaller, quadrangular, in contact with supraocular and parietal broad, in narrow contact with anterior temporal; lower postocular crescent in contact with 4th and 5th SUP ventrally, anterior temporal posteriorly; temporals 1+2, elongated, hexagonal; anterior temporal larger and longer than posterior temporals, in contact with parietal dorsally, 5th and 6th SUP ventrally; posterior temporals smaller, lower one in contact with 6th and 7th SUP ventrally.
Supralabials 7 on both sides, 4th–7th larger in size; 1st SUP in contact with rostral anteriorly, nasals dorsally, 2nd SUP with posterior nasal and loreal dorsally, 3rd SUP with preocular and orbit dorsally, 4th SUP with orbit and the lower postocular dorsally, 5th SUP with lower postocular and anterior temporal dorsally, 6th SUP with anterior temporal and lower posterior temporal, and 7th SUP with lower posterior temporal dorsally and body scales posteriorly.
Mental moderate, triangular; first infralabial pair larger than mental and contact with each other broad, in contact with anterior chin shield posteriorly; eight infralabials, 1st–5th in contact with first chin shield, 5th infralabial largest in size in narrow contact with anterior chin shield and contact with posterior chin shield broad; 6th–8th infralabials in contact with gular scales; two larger anterior chin shields, and two smaller posterior chinshields all in broad contact; posterior chin shield bordered posteriorly by six gular scales.
Body robust, elongate and sub cylindrical; costal scales in 17-15-15 rows, all smooth and bluntly pointed; 138 (142) ventral scales; anal plate divided. NMSL 5161 has an everted hemipenis covered by lobes, non-bifurcated, slightly clavate; base naked;
A live male of
This species has never been recorded outside of Sri Lanka, hence we here restrict terra-typica to Sri Lanka.
Distribution pattern of
The result of the application of the
A nocturnal snake, sometimes active during day time. Temperature, humidity, and light intensities for daytime activity were respectively measured at 24.8–27.2 °C, 67–82%, and 38–365 lux, based on 50 observations in dense forested areas. It usually does not bite, but if this does occur then it will lead to soreness, pain and temporary bleeding in the victim. Biting has been occasionally observed during touching or handling attempts by the victim. When frightened, the snake either coils up and hides its head within its coiled up body; or it quickly tries to escape to a safe hiding place inside the leaf litter. When the snake coils, it enlarges its body and displays its vivid skin colours (white, pink and brown), which is visible between the scales around the mid body. We observed, on a number of occasions, the snake practicing thanatosis (death mimicry) for up to 10–15 minutes after carrying out our own handling attempts. Once the snake had noticed that threat had disappeared, it quickly escaped and hid itself in the leaf litter. We have observed this species living in sympatry with other snakes of several families such as
Based on our observations, its diet consists mostly of lizards (saurophagy) and small snakes eggs (oophagy), small spiders, beetles, other insects and the larvae of other invertebrates. More specifically, we observed the snake feeding on ground dwelling skinks (
During the breeding season (May–June) 3–5 individuals can be observed close by and we observed several copulations in the evenings just after dark (18.0–19.0 hrs). The species lays 3–5 eggs at a time on dry, cool, loose soil or under decaying logs on the ground (soil temperature 26.2–27.9 °C; humidity 58–73%; light intensity 0–27 lux, based on observations of 10 ovipositions). Eggs are cream in colour and oval in shape (12–14 mm long and 4–5 mm wide, n = 40). The lectotype MNHN 3238 is a gravid female with three eggs in its genital tract. The incubation period is 38–45 days (based on observations of 10 incubating clutches). We did not see the parents close by during the incubation nor shortly afterwards, indicating the lack of parental care of the eggs or hatchlings. The new born juveniles were 4–5 cm in total length and their body colour varied from dark brown to black. We noticed that ants were their main egg predators on about ten occasions. We also observed on several occasions, this snake attempting to avoid ant-nests when moving or resting.
We have found this species inside termite mounds on many occasions, an observation also made by
Road kills are identified as a major growing threat in addition to forest fragmentation and habitat loss. People are also a threat, killing the snake out of fear, believing that it to be venomous, especially because as it displays such vivid head and body colours. We observed natural predators including birds: the yellow-billed babbler [
In the description of
To be sure that there are no other specimens which could possibly be a syntype, we examined all the available
Louis-Augustin-Guillaume Bosc (1759–1828) was a French botanist, zoologist, and politician during the Revolution, who described many amphibians and reptiles of eastern North America. He also described the Savanna Monitor (
We are very grateful to Gernot Vogel, A. de Silva, P. Uetz, W.M.S. Botejue, D.E. Gabadage, N. Gamage, M.M. Bahir, M.C. De Silva, H. Jayasinghe, V. Weeratunga, M. Madawala, S. Fernando, S. Wellapulliarachchi, P. Samarawickrama, M. Wickramasighe, D. Kandambi, P. Pieris, and G.N. Karunarathna who provided valuable support which enabled us to complete this study. We also thank N. Wickramasinghe, S. Kasthuriarachchi, M. Nandasena, C. Munasinghe, L. Somaratne, R. Dasanayake, M.B. Vaidyasekara, C. Kotalawala, A. Samanthika, P. Gunasiri and R. Wickramanayake at National Museum of Sri Lanka (NMSL) for assisting us while examining collections under their care. Special thanks to D. Vallan for providing information linked to the specimens at NMB. We thank J. Supriatna and the staff of the Research Center for Climate Change of the University of Indonesia (RCCC-UI) for their support. Finally, we thank the field staff of Forest Department and Department of Wildlife Conservation, Sri Lanka.
Other materials examined