Trimeresurus ciliaris, Idiiatullina & Pawangkhanant & Tawan & Worranuch & Dechochai & Suwannapoom & Nguyen & Chanhome & Poyarkov, 2023
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publication ID |
https://dx.doi.org/10.3897/vz.73.e109854 |
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publication LSID |
lsid:zoobank.org:pub:CA5997B2-B462-4B40-B861-EFF08FC1768D |
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persistent identifier |
https://treatment.plazi.org/id/898F9CF2-0457-4F77-B53A-BB8D1E8AB3F2 |
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taxon LSID |
lsid:zoobank.org:act:898F9CF2-0457-4F77-B53A-BB8D1E8AB3F2 |
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treatment provided by |
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scientific name |
Trimeresurus ciliaris |
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sp. nov. |
Trimeresurus ciliaris sp. nov.
Figures 3 View Figure 3 , 4 View Figure 4 , 5 View Figure 5
Chresonymy.
Cryptelytrops cf. venustus (partim): Chan et al. (2011: 258).
Holotype.
ZMMU Re-17661, adult male collected by S. Idiiatullina, P. Pawangkhanant and T. Woranuch on 23 January 2023 near Thum Khao Ting, Palian District, Trang Province, Thailand (07°09.943N, 99°48.142E; elevation 28 m a.s.l).
Paratypes (n = 4).
QSMI 1538, adult female collected by P. Pawangkhanant on 18 June 2016 from the same locality as the holotype; AUP-02011, ZMMU Re-17662, ZMMU Re-17663, three adult males collected on 23 January 2023 from the same locality and by the same collectors as for the holotype.
Diagnosis.
A species of the genus Trimeresurus which is assigned to the subgenus Trimeresurus Trimeresurus based on the following morphological attributes: a long papillose or calyculate hemipenis and partially fused first supralabial and nasal scales ( Malhotra and Thorpe 2004a; David et al. 2011). The new species Trimeresurus ciliaris sp. nov. can be distinguished from all other congeneric species by the following combination of morphological characters: three or four small convex supraocular scales; internasals not in contact; small scale between nasal and the scale formed by the fused second supralabial and loreal present; dorsal scales in 17-17-15 rows; ventral scales 172-175 in males, 171 in a single female; subcaudal scales 59-63 in males, 52 in a single female, all paired; in life an emerald-green dorsum with reddish-brown cross-bands; creamy-white venter lacking dark dots or stripes on the lateral sides of the ventrals; iris olive-green with faded-brown horizontal stripe; tail dark brown mottled with rusty spots; white vertebral spots present in both sexes located approximately every two or three dorsal scales; dark brown spots forming discontinuous pattern present on 1-3 lateral dorsal scale rows; males having a reddish-brown postocular stripe.
Description of the holotype.
Adult male (Fig. 3 View Figure 3 ), specimen in a good state of preservation. Body cylindrical, long and thin (SVL 345 mm, TaL 72 mm, TL 417 mm, TaL/TL 0.17) (Fig. 3A,B View Figure 3 ). Head triangular in dorsal view (Fig. 3C View Figure 3 ), elongate, clearly distinct from the neck (HL 16.5 mm, HW 11.4 mm, HW/HL 0.69). Snout elongate, flattened and rounded in dorsal view (Fig. 3C View Figure 3 ), rather rectangular in lateral view (Fig. 3E,F View Figure 3 ), with a very distinct and sharp canthus rostralis (SnL/HL 0.30, SnL/ED 1.92). Distance between eye and nostril 3.9 mm on both sides. Rostral slightly visible in dorsal aspect, triangular (Fig. 3C View Figure 3 ). Pupil vertically elliptical, loreal pit present, triangular in shape (Fig. 3E,F View Figure 3 ). Nostril completely enclosed in nasal scale; nasal scale partially fused with first supralabial (Fig. 3E View Figure 3 ). Shield bordering the anterior edge of loreal pit fused with second supralabial. Anterior subocular long, thin, and crescent-like, separated from the 4th and 5th supralabials by one row of scales; posterior subocular ovoid, separated from the 6th supralabial by 2/1 scales (Fig. 3E, F View Figure 3 ). Three preoculars on each side of the head; two upper preoculars located above the loreal pit, elongated, in contact with the single loreal which separates them from the nasal; lower preocular forming the lower margin of the loreal pit, lower preocular in contact with third supralabial (Fig. 3E, F View Figure 3 ). A small scale between the nasal and the scale formed by the fused second supralabial and loreal; 2/2 postoculars; 9/9 supralabials, third the largest (Fig. 3E,F View Figure 3 ); 11/10 infralabials, those of the first pair in contact with each other behind the mental; the first three pairs of infralabials in contact with the single pair of chin shields (Fig. 3D View Figure 3 ). Six pairs of gulars aligned between the chin shields and the first preventral (Fig. 3D View Figure 3 ). One large pair of enlarged internasals, separated by three small scales. Three small slightly convex supraoculars, same size as or smaller than preoculars and postoculars (Fig. 3C View Figure 3 ). Scales on snout and in the interorbital region smooth, irregular, subimbricate; temporal and occipital scales moderately keeled (Fig. 3C,E,F View Figure 3 ). Dorsal scales in 17-17-15 rows. Dorsal scales all strongly keeled, except the first row, which is smooth (Fig. 3H View Figure 3 ). One preventral + 172 ventrals. Cloacal plate single; 61 subcaudals, all divided. Hemipenes long, papillose, and deeply forked with small, soft, basal spines (Fig. 3G View Figure 3 ). Each maxilla bearing a single large venom tooth; three teeth on palatine, 11 on pterygoid, and 12 on dentary.
Coloration in life (Figs 3 View Figure 3 - 5 View Figure 5 ).
Dorsal surface of the head emerald-green with many scales partly or entirely dark red, especially on the snout, and on the interorbital, temporal and occipital regions (Fig. 3C View Figure 3 ). A reddish-brown postocular stripe extends from postocular scales to the neck (Fig. 3E,F View Figure 3 ). Black vertical pupil; iris olive-green with faded brown horizontal stripe (Fig. 3E,F View Figure 3 ). The background color of the dorsum emerald-green, similar to that of the head, with about 75 irregular, dark red cross-bands (Fig. 3A View Figure 3 ). These red bands are about two dorsal scales long mediodorsally, but getting narrower on the lower flanks where they are about 1-2 dorsal scale in length. At the level of the vertebral row, the red bands are generally separated by one dorsal scale. White vertebral spots present along the vertebral scale row, approximately every two or three scales (Fig. 3A View Figure 3 ). Ventrolateral stripe absent. Dark brown spots forming discontinuous pattern present on first to third lateral dorsal scale rows (Fig. 3H View Figure 3 ). Tail dark brown mottled with rusty spots. Ventral surface of the tail dark brown with white irregular bands, tail tip completely black. Infralabials greenish-white with faint brown spots (Fig. 3E,F View Figure 3 ); the ventral surfaces of the head creamy white with bluish tint (Fig. 3D View Figure 3 ); the ventral surfaces of body creamy white (Fig. 3B View Figure 3 ).
In preservative the background dorsal color faded to greyish-brown, with less contrasting dark marks on the head and bands on the dorsum; the ventral color became whitish grey.
Variation.
The main meristic and morphometric characters of the type series of Trimeresurus ciliaris sp. nov. are summarized in Table 4 View Table 4 ; color variation of the type series is presented in Figures 4 View Figure 4 , 5A View Figure 5 , 6A-B View Figure 6 , 7B-E View Figure 7 . All members of the type series, similarly to the holotype, show a nasal scale partially fused with the first supralabial. Head scalation of the paratypes generally agrees with that of the holotype, however male ZMMU Re-17662 has a suboculars fused in a single long crescent-shaped scale (Fig. 4B View Figure 4 ), while the two males AUP-02011 (Fig. 4C View Figure 4 ) and ZMMU Re-17663 (Fig. 4D View Figure 4 ) have four small supraoculars on each side of the head instead of three as in the holotype. Coloration of paratypes is very similar to that of the holotype; all specimens have a creamy-white belly and lack ventrolateral stripe. Female specimen QSMI 1538 has slightly lower number of subcaudals than in males (SC 52 vs. 59-63). The white vertebral spots are present both in males and in females; they are regularly spaced by two or three vertebral scales. The number of dark bands on dorsum varies from 70 to 81 among the members of the type series, without apparent sexual dimorphism. Coloration of female specimen QSMI 1538 largely faded due to preservation in formalin for seven years.
Distribution and natural history.
Currently, Trimeresurus ciliaris sp. nov. is known only from a narrow limestone area in the Nakawan Range spanning the border of Thailand and Malaysia, in particular in limestone forests in Trang (Palian District) and Satun (Tha Le Ban National Park) provinces, Thailand (Fig. 1 View Figure 1 ). It is highly likely that the new species also inhabits the northernmost part of Perlis State of Peninsular Malaysia (Fig. 1 View Figure 1 , see Discussion for details). The new species occurs in lowland dipterocarp forest on limestone rocks and appears to be strongly associated with a karst landscape. The new species was recorded for the first time in limestone formations within the Tha Le Ban National Park, Satun Province of Thailand, in June 2016 (P. Pawangkhanant pers. obser.), where it was observed in a lowland dipterocarp forest with numerous large karst rocks. Almost all specimens of Trimeresurus ciliaris sp. nov. were collected during daytime (except ZMMU Re-17663 that was collected at night around 20h50). All specimens were found near large boulders of karst rocks covered with dense vegetation and leaf litter (Fig. 7A View Figure 7 ); one specimen was found after heavy rain around 18h00 while perching vertically on a limestone rock surface ca. 5 m above the ground.
In captivity, due to its small size, this species of pitviper mostly feeds on small geckos and microhylid frogs [ Microhyla butleri Boulenger, M. cf. heymonsi Vogt, and Micryletta cf. lineata (Taylor)]. Nothing is known about the diet of the new species in the wild, but in one specimen from Mueang District, Satun Province, caudal luring behavior was observed: the male specimen was wiggling its tail tip when an adult Gekko gecko Cnemaspis biocellata Grismer, Chan, Nasir & Sumontha approached its shelter. Other amphibian and reptile species recorded in syntopy with the new species include: Ingerophrynus parvus (Boulenger), Micryletta cf. lineata , Microhyla butleri , Kaloula latidisca (Chan, Grismer & Brown), Cnemaspis niyomwanae Grismer, Sumontha, Cota, Grismer, Wood, Pauwels & Kunya, C. biocellata , Gekko gecko (Linnaeus), Cyrtodactylus astrum Grismer, Wood, Quah, Anuar, Muin, Sumontha, Ahmad, Bauer, Wangkulangkul, Grismer & Pauwels, C. quadrivirgatus Taylor, Cyrtodactylus sp., Elaphe taeniura ridleyi (Cope), and Tropidolaemus wagleri (Boie).
Etymology.
The species name " Trimeresurus ciliaris " is a Latin adjective in the nominative singular, masculine gender, derived from Latin word " cilium " meaning "an eyelash", and is given in reference to the characteristic small and distinct supraocular scales in the new species, which resemble eyelashes or eyebrows in lateral view. We suggest the following common names for the new species: "Ngu Hang Mhai Khao Hin Poon" (งูหางไหม้เขาหินปูน) (in Thai), "Limestone Eyelash Pitviper" (in English), and " Resni-tchataya ukrashennaya kufiya " (in Russian).
Comparisons.
The new species is morphologically and phylogenetically placed within the subgenus Trimeresurus ( Malhotra and Thorpe 2004a; David et al. 2011) and morphologically is overall most similar to other limestone-dwelling pitviper species, including T. kanburiensis , T. kuiburi , and T. venustus s. str., so the comparisons with these three species appear to be the most pertinent. Trimeresurus ciliaris sp. nov. can be easily distinguished from other congeners by having: 17 midbody scale rows, three or four small supraocular scales, and a small scale between the nasal and the scale formed by the fused second supralabial and loreal. The main diagnostic characters separating Trimeresurus ciliaris sp. nov. from these three species are summarized in Table 5 View Table 5 . The comparison of body coloration and head scalation of these species is presented in Figures 5 View Figure 5 and 6 View Figure 6 , respectively. From the superficially similar Trimeresurus truongsonensis Orlov, Ryabov, Vu & Ho, a member of the subgenus Trimeresurus Viridovipera , the new species can be easily distinguished by having a long papillose and deeply forked hemipenis (vs. short spinose hemipenis) and partially fused first supralabial and nasal scales (vs. separate).
In particular, Trimeresurus ciliaris sp. nov. differs from T. kanburiensis by having: smaller maximal SVL (360 mm in male, 333 mm in female vs. 412 mm in male, 572 mm in female); lower anterior number of dorsal scale rows (17 vs. 23, rarely 21 or 22); lower number of midbody scale rows (17 vs. 19); absence of dark lateral stripe on ventrals, Fig. 5A View Figure 5 (vs. dark lateral stripe on ventrals always present, discontinuous, olive-brown, Fig. 5B View Figure 5 ); three or four small supraocular scales, Fig. 6B View Figure 6 (vs. single large supraocular scale, Fig. 6D View Figure 6 ); body color in life (reddish-brown bands on an emerald-green background [Fig. 5A View Figure 5 ] vs. dark olive-brown bands on olive-greyish background [Fig. 5B View Figure 5 ]); white vertebral spots present in both sexes separated by 2-3 dorsal scales vs. white vertebral spots present only in males and are separated by 3-5 dorsal scales; iris color (olive-green with faded brown horizontal stripe [Fig. 6A View Figure 6 ] vs. brown, slightly golden [Fig. 6C View Figure 6 ]); and tail color (dark brown mottled with rusty spots vs. brownish-gray with olive-brown blotches).
Trimeresurus ciliaris sp. nov. further differs from T. kuiburi by having: smaller maximal SVL in female (333 mm vs. 451 mm); internasals separated by two or three scales (vs. always in contact); lower anterior number of dorsal scale rows (17 vs. 21 rarely 23); lower number midbody scale rows (17 vs. 19); higher number of ventrals in females (172-175 vs. 164-166); ventral surfaces of body creamy-white (vs. pale-green); three or four small supraocular scales, Fig. 6A View Figure 6 (vs. one large supraocular scale, Fig. 6F View Figure 6 ); small scale between nasal and second supralabial present vs. absent; body color in life (reddish-brown bands on emerald-green background [Fig. 5A View Figure 5 ] vs. red to purple bands on bottle-green background [Fig. 5C View Figure 5 ]); white vertebral spots present in both sexes separated by 2-3 dorsal scales vs. white vertebral dots present only in males and are separated by 5-6 dorsal scales; iris color (olive-green with faded brown horizontal stripe [Fig. 6A View Figure 6 ] vs. copper [Fig. 6E View Figure 6 ]); and tail color (dark brown mottled with rusty spots vs. red with some thin lighter bands).
Trimeresurus ciliaris sp. nov. can be further differentiated from T. venustus s. str. by having: smaller maximal SVL (360 mm in male, 333 mm in female vs. 490 mm in male, 456 mm in female); lower anterior number of dorsal scale rows (17 vs. 23, rarely 21 or 25); lower number midbody scale rows (17 vs. 21, rarely 19); white vertebral spots present in both sexes separated by 2-3 dorsal scales (vs. absent); ventral surfaces creamy-white (vs. pale-green); lateral dark stripe on ventrals absent (vs. lateral dark stripe on ventrals always present, discontinuous, red); three or four small supraocular scales, Fig. 6A View Figure 6 (vs. one large supraocular scale, Fig. 6H View Figure 6 ); small scale between nasal and second supralabial present vs. absent; body color in life (reddish-brown bands on emerald-green background [Fig. 5A View Figure 5 ] vs. red to purple bands on dark bottle-green background [Fig. 5D View Figure 5 ]); white vertebral spots present in both sexes separated by 2-3 dorsal scales vs. white vertebral dots absent in both sexes; iris color (olive-green with faded brown horizontal stripe [Fig. 6A View Figure 6 ] vs. yellowish-brown to gold [Fig. 6G View Figure 6 ]); and tail coloration (dark brown mottled with rusty spots vs. brown with dark purplish-brown crossbars).
Among the other species in the subgenus Trimeresurus Trimeresurus , the new species can be readily distinguished from T. albolabris , T. andersonii , T. cantori , T. cardamomensis , T. caudornatus , T. davidi , T. erythrurus , T. fasciatus , T. guoi , T. honsonensis , T. insularis , T. labialis , T. macrops , T. mutabilis , T. purpureomaculatus , T. rubeus , T. salazar , and T. septentrionalis by body coloration and pattern (reddish-brown bands on emerald-green background in the new species vs. uniform green or green coloration with no pattern, or pattern consisting of small brownish spots or speckles in other species, or straw-yellow background with irregular, dark-brown transverse body bands in T. honsonensis ). Moreover, by having 17 MSR, the new species can be further separated from T. albolabris (21 MSR), T. andersonii (21 MSR), T. cantori (27, 29 or 31 MSR), T. cardamomensis (21 MSR), T. caudornatus (21 MSR), T. davidi (21 or 23 MSR), T. erythrurus (23 rarely 21, 25 MSR), T. fasciatus (21 MSR), T. guoi (21 MSR), T. honsonensis (21 MSR), T. insularis (21 MSR), T. labialis (21 or 23 MSR), T. macrops (21 MSR), T. mutabilis (21 MSR), T. purpureomaculatus (25 rarely 27, 29 MSR), T. rubeus (21 MSR), T. salazar (21 MSR), and T. septentrionalis (21 MSR) (see Gumprecht et al. 2004; Grismer et al. 2008; Malhotra et al. 2011; Chandramouli et al. 2020; Chen et al. 2020, 2021; Mirza et al. 2020; our data).
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