Research Article |
Corresponding author: Dingqi Rao ( raodq@mail.kiz.ac.cn ) Academic editor: Alexander Haas
© 2021 Shuo Liu, Mian Hou, Ye Htet Lwin, Qiaoyan Wang, Dingqi Rao.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Liu S, Hou M, Lwin YH, Wang Q, Rao D (2021) A new species of Gonyosoma Wagler, 1828 (Serpentes, Colubridae), previously confused with G. prasinum (Blyth, 1854). Evolutionary Systematics 5(1): 129-139. https://doi.org/10.3897/evolsyst.5.66574
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A new species of the genus Gonyosoma Wagler is described from Yunnan Province, China. The new species closely resembles G. prasinum (Blyth), but it is differentiated from the latter species by the following characters: precloacal plate divided, iris blue and inside of mouth greyish-white in life. Based on phylogenetic analyses of mitochondrial cytochrome b sequence data, the new species is recovered as the sister species to G. prasinum by Bayesian Inference and Maximum Likelihood analyses. The uncorrected pairwise distance between the new species and other species of the genus Gonyosoma ranged from 11.78% to 17.07% calculated using the mitochondrial cytochrome b sequence. This discovery increases the number of Gonyosoma species to seven.
Htamanthi, morphology, phylogeny, systematics, taxonomy, Yunnan
Once considered members of a single genus, Elaphe Fitzinger, the ratsnakes have been divided into a number of genera including Gonyosoma (
Gonyosoma prasinum, a wholly green, arboreal snake (
During our fieldworks in southern China and northern Myanmar from 2019 to 2020, some specimens of Gonyosoma cf. prasinum were collected, six from Yunnan Province, China, and two from Htamanthi Wildlife Sanctuary, northwestern Myanmar, relatively close to the type locality of G. prasinum. The specimens from China and Myanmar showed some differences in scale counts and coloration in life. In addition, phylogenetically, the sequences of the specimens from China and from Myanmar were placed in two separate clades and had an obvious genetic divergence. Therefore, we treated the specimens from China and from Myanmar to be two distinct species.
The question was, which one is the true Gonyosoma prasinum? As no molecular data for the type specimens is available, we can only solve this problem through morphological characteristics. However, we cannot judge this problem from the original description (
Field surveys in Yunnan, China, were conducted under the permits of Xishuangbanna National Natural Reserve Management Bureau and Wuliangshang National Nature Reserve Management Bureau. Field survey in Northern Myanmar was undertaken at the invitation of the Republic of the Union of Myanmar, Ministry of Natural Resources and Environmental Conservation, Forest Department, Forest Research Institute. Four specimens (KIZ2019025–KIZ2019028) were collected from Mengla County, Yunnan Province, China, in April to May 2019, one specimen (KIZ20200729) was collected from Zhenyuan County, Yunnan Province, China, in July 2020, one specimen (KIZ20200903) was collected from Menglian County, Yunnan Province, China, in September 2020, and two specimens (SEABRI2019120043, SEABRI2019120075) were collected from Htamanthi wildlife sanctuary, Sagaing, Myanmar, in December 2019. Specimens were collected by hand, and photographs were taken to document color pattern in life prior to euthanasia. Liver tissues were stored in 99% ethanol and snakes were preserved in 75% ethanol. The specimens from China were deposited in Kunming Institute of Zoology, Chinese Academy of Sciences (
All species of the genus Gonyosoma were included in the study. Homologous sequences were obtained from GenBank. Six samples from China and two sample from Myanmar were incorporated in the analysis, and the new sequences have been deposited in GenBank. Elaphe taeniura (Cope) and Coelognathus radiatus (Boie) were used as outgroups. All the GenBank accession numbers for taxa used in this study were listed in Table
Species | Voucher | Locality | Accession |
---|---|---|---|
Coelognathus radiatus | CHS556 | Wenshan, Yunnan, China | MK201411 |
Elaphe taeniura | CHS203 | Xiangcheng, Sichuan, China | MK201333 |
Gonyosoma boulengeri | YPX11032 | / | AF471053 |
CHS242 | Mengzi, Yunnan, China | MK201360 | |
CHS243 | Hainan, China | MK201361 | |
Gonyosoma frenatum | YPX11027 | / | KF669250 |
HS11038 | / | KF669251 | |
EXTRACTION | / | KF669246 | |
/ | / | DQ902110 | |
CHS138 | Huangshan, Anhui, China | MK201289 | |
CHS139 | Huangshan, Anhui, China | MK201290 | |
Gonyosoma jansenii | / | Sulawesi | DQ902113 |
KU 321724 | Zamboanga, Mindanao, Philippines | KC010343 | |
Gonyosoma margaritatum | / | / | KM870886 |
Gonyosoma oxycephalum | / | / | AF471084 |
ROM 37622 | / | KX694870 | |
Gonyosoma prasinum | SEABRI2019120043 | Htamanthi, Sagaing, Myanmar | MZ322864 |
SEABRI2019120075 | MZ322863 | ||
Gonyosoma coeruleum sp. nov. | KIZ2019025 | Mengla, Yunnan, China | MZ322870 |
KIZ2019026 | MZ322869 | ||
KIZ2019027 | MZ322868 | ||
KIZ2019028 | MZ322867 | ||
KIZ20200729 | Zhenyuan, Yunnan, China | MZ322866 | |
KIZ20200904 | Menglian, Yunnan, China | MZ322865 |
DNA was extracted using DNeasy Blood and Tissue kit (Qiagen, Germany) following the manufacturer’s instructions. A fragment of mitochondrial cytochrome b (cytb) gene was amplified using the primer pair L14910: 5’–GACCTGTGATMTGAAAACCAYCGTT–3’ and H16064: 5’–CTTTGGTTTACAAGAACAATGCTTTA–3’ (
Sequences were aligned using ClustalX 2.0 (
Body and tail lengths were measured with a ruler to the nearest 1 mm (
The topologies derived from Bayesian inference and Maximum Likelihood analysis were consistent (Fig.
Average uncorrected p-distances (%) between members of Gonyosoma and outgroups calculated from cytb gene sequences.
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
---|---|---|---|---|---|---|---|---|
1 Gonyosoma coeruleum sp. nov. | ||||||||
2 Gonyosoma boulengeri | 13.01 | |||||||
3 Gonyosoma frenatum | 13.35 | 7.56 | ||||||
4 Gonyosoma jansenii | 17.07 | 15.63 | 16.88 | |||||
5 Gonyosoma margaritatum | 12.33 | 12.51 | 12.41 | 16.91 | ||||
6 Gonyosoma oxycephalum | 15.77 | 15.32 | 16.36 | 7.75 | 15.98 | |||
7 Gonyosoma prasinum | 11.78 | 12.89 | 12.65 | 17.69 | 12.71 | 15.96 | ||
8 Coelognathus radiatus | 19.32 | 18.40 | 18.15 | 19.49 | 18.97 | 19.66 | 17.35 | |
9 Elaphe taeniura | 16.27 | 15.56 | 15.59 | 16.21 | 16.07 | 16.92 | 16.32 | 15.90 |
Morphological measurements, scale counts and colorations in life were presented in Table
The consistent phylogram inferred from Bayesian Inference and Maximum Likelihood analyses based on cytb gene sequences. Numbers before slashes indicate Bayesian posterior probabilities (values below 0.9 were not shown) and numbers after slashes indicate bootstrap support for Maximum Likelihood analyses (values below 60 were not shown).
Measurements (in mm), scalation data, and coloration of Gonyosoma coeruleum sp. nov. and G. prasinum. For abbreviations see Materials and methods.
Gonyosoma coeruleum sp. nov. | Gonyosom prasinum | |||||||
KIZ2019028 Holotype | KIZ2019025 Paratype | KIZ2019026 Paratype | KIZ2019027 Paratype | KIZ20200729 Paratype | KIZ20200904 Paratype | SEABRI2019120043 | SEABRI2019120075 | |
Sex | Female | Female | Male | Male | Female | Juvenile | Male | Male |
SVL | 814 | 656 | 833 | 719 | 696 | 388 | 487 | 577 |
TL | 1058 | 863 | 974+ | 992 | 918 | 511 | 656 | 779 |
TaL | 245 | 207 | 141+ | 273 | 222 | 123 | 169 | 202 |
TaL / TL | 0.23 | 0.24 | 0.14+ | 0.28 | 0.24 | 0.24 | 0.26 | 0.26 |
SL | 8/9 | 9/9 | 9/9 | 9/9 | 9/9 | 9/9 | 9/9 | 9/9 |
SL / orbit | 3-5/4-6 | 4-6 | 4–6 | 4–6 | 4–6 | 4–6 | 4–6 | 4–6 |
IL | 10/10 | 10/10 | 10/10 | 10/10 | 11/10 | 10/10 | 11/10 | 10/10 |
PreOc | 1/1 | 1/1 | 1/1 | 1/1 | 1/1 | 1/1 | 1/1 | 1/1 |
PostOc | 2/2 | 2/2 | 2/2 | 2/2 | 2/2 | 2/2 | 2/2 | 2/2 |
Lor | 1/1 | 1/1 | 1/1 | 1/1 | 1/1 | 1/1 | 1/1 | 1/1 |
Lor / eye | no | No | no | no | no | no | no | no |
Atem | 2/2 | 2/2 | 2/2 | 1/1 | 1/2 | 1/1 | 1/1 | 1/2 |
PTem | 2/2 | 3/2 | 2/2 | 2/2 | 2/2 | 2/2 | 1/1 | 2/2 |
DSR | 19-19-15 | 19-19-15 | 19-19-15 | 19-19-15 | 19-19-15 | 19-19-15 | 19-19-13 | 19-19-15 |
Ven | 202 | 199 | 196 | 190 | 189 | 195 | 194 | 193 |
SubC | 89 | 103 | 44+ | 106 | 93 | 105 | 104 | 105 |
Prec | Divided | Divided | Divided | Divided | Divided | Divided | Single | Single |
Body color | Green | Green | Green | Green | Green | Green | Green | Green |
Tongue color | Brownish yellow | Brownish yellow | Brownish yellow | Brownish yellow | Brownish yellow | Brownish yellow | Brownish yellow | Brownish yellow |
Inside of mouth | Greyish white | Greyish white | Greyish white | Greyish white | Greyish white | Greyish white | Pink | Pink |
Iris color | Blue | Blue | Blue | Blue | Blue | Blue | Greenish yellow | Greenish yellow |
KIZ2019028, adult female, Mengla County, Xishuangbanna Autonomous Prefecture, Yunnan Province, China, 29 April 2019, 21°32'12"N, 101°32'51"E, 900 m a.s.l.
KIZ2019025, one adult female and KIZ2019026–KIZ2019027, two adult males, Mengla County, Xishuangbanna Autonomous Prefecture, Yunnan Province, China, 4 May 2019, 21°55'9"N, 101°32'12"E, 890 m, a.s.l. KIZ20200729, adult female, collected from Zhenyuan County, Puer City, Yunnan Province, China, 29 July 2020, 24°3'37"N, 101°3'43"E, 1,240 m a.s.l. KIZ20200904, one juvenile, collected from Menglian County, Puer City, Yunnan Province, China, 3 September 2020, 22°10'16"N, 99°18'31"E,1,200 m a.s.l.
The specific epithet “coeruleum” is the neutral gender of the Latin adjective coeruleus (a, um) meaning “blue”, and is given in reference to the coloration of the iris of this species.
Body size medium (SVL 656–833mm in adults); body slender, head elongated and distinct from neck; large eyes with round pupil; tail long (23–28% of total length) and slender; dorsal scales in 19-19-15 rows, 7–11 rows of mid-dorsal scales keeled; single preocular; two postoculars; one or two anterior temporals and two or three posterior temporals; 189–202 ventral scales; 89–106 paired subcaudals; precloacal plate divided. Dorsal surface bright green with brownish-yellow tip of tail, iris blue, inside of mouth greyish white; tongue brownish yellow with black tips.
Head elongate, distinct from the neck, flattened, longer than wide, narrowed anteriorly; nostril lateral; eye large, pupils round; rostral triangular, broader than high, visible from above; nasal divided into two scales; two internasals, wider than high, bordered by two large prefrontals posteriorly; frontal single, enlarged, pentagonal, narrowed posteriorly; parietals longer than wide, in contact with each other; supralabials 8/9, first and second in contact with the prenasal and postnasal, third and fourth entering orbit on left side, fourth and sixth entering orbit on right side, eighth largest; infralabials 10/10, first pair in broad contact with each other, first to fifth in contact with anterior pair of chin shields; anterior and posterior pairs of chin shields elongate, second pair meeting in midline; preocular 1/1; postoculars 2/2, lower ones smaller, bordering anterior temporals; anterior temporals 2/2, posterior temporals 2/2. SVL 814 mm; TaL 245 mm; TaL/TL 0.23; DSR 19-19-15, nine rows keeled in the vertebral region, otherwise smooth; ventrals 202 with a lateral keel; subcaudals 89, paired; precloacal plate divided.
Dorsal surface bright green with brownish-yellow tip of tail, reticulate pattern consisting of yellow, black, and white on the interstitial skin; upper lips yellowish-green; anterior ventral surface greenish-white and posterior ventral surface light green; tip of tail brownish-yellow on its ventral surface; ventrals outside the lateral keel usually yellowish-white; iris blue; pale grey inside of mouth; tongue brownish-yellow with black tips.
The paratypes resemble the holotype in most aspects except that the rows of mid-dorsal scales keeled vary from seven to eleven, anterior temporals vary from one to two, and posterior temporals vary from two to three in paratypes; moreover, the male paratype KIZ2019027 has a relatively longer tail (TaL/TL 0.28).
The specimens of Gonyosoma coeruleum sp. nov. and G. prasinum in life. A the female paratype (KIZ20200729) of Gonyosoma coeruleum sp. nov. B the juvenile paratype (KIZ20200904) of Gonyosoma coeruleum sp. nov. C the specimen (SEABRI2019120043) of G. prasinum from Myanmar D the specimen (SEABRI2019120075) of G. prasinum from Myanmar.
Gonyosoma coeruleum sp. nov. is currently known from Xishuangbanna Autonomous Prefecture and Puer City, Yunnan Province, China (Fig.
Map showing the type locality of Gonyosoma coeruleum sp. nov. (blue star) in Mengla County, Yunnan Province, China; the other collection sites of Gonyosoma coeruleum sp. nov. in Zhenyuan County (blue pentagon) and Menglian County (blue triangle), Yunnan Province, China; the type locality (green square) of G. prasinum in Assam, India; and the new collection site (green dot) of G. prasinum in Htamanthi wildlife sanctuary, Sagaing, Myanmar.
The specimens from Mengla County were collected on big trees bordering rivers, the specimen from Zhenyuan County was collected on a big tree on the side of a small road in forest, and the specimen from Menglian County was collected on a small tree bordering a stream. All specimens were found at night while they were asleep on tree branches, what shows that this species is diurnal. Through direct observation, we found that they like to feed on small rodents, and whether they also prey on other animals is unknown.
Gonyosoma coeruleum sp. nov. can be distinguished from G. boulengeri in lacking a nasal appendage (vs. rostral distinct from the nasal appendage), and no dark stripe behind the eye (vs. an indistinct dark stripe behind the eye) (
Gonyosoma coeruleum sp. nov. is distinguishable from G. frenatum based on its single, distinct loreal (vs. loreal united with the prefrontal), and no black streak along the side of the head (vs. a black streak along the side of the head above the supralabials) (
Gonyosoma coeruleum sp. nov. can be separated from G. jansenii by having 19 midbody dorsal scale rows (vs. 23–25), and dorsal surface uniform bright green with brownish-yellow tip of tail (vs. olive or yellowish-brown, entirely black posteriorly and on the tail) (
From Gonyosoma margaritatum, Gonyosoma coeruleum sp. nov. can be differentiated by its dorsal surface uniform bright green with brownish-yellow tip of tail (vs. black, each scale with a yellowish green spot, or green with black borders to the scales, hinder part of body and tail with bright orange rings), and no black streak on each side of the head (vs. a black streak on each side of the head behind the eye) (
A habitat at the type locality of Gonyosoma coeruleum sp. nov. B Gonyosoma coeruleum sp. nov. asleep on a tree at night.
From Gonyosoma oxycephalum, Gonyosoma coeruleum sp. nov. can be differentiated by the different colors of tail (green with brownish-yellow tip vs. the whole tail light chestnut or buff-red or yellowish brown), no blackish stripe along the side of the head (vs. an indistinct blackish stripe along the side of the head immediately above the supralabials), and the number of midbody dorsal scale, 19 rows (vs. 23–27 rows) (Boie 1827;
Gonyosoma coeruleum sp. nov. closely resembles G. prasinum, but the colorations of their iris in life are obviously different, the iris of Gonyosoma coeruleum sp. nov. is blue (Fig.
One type specimen of Gonyosoma prasinum is currently available in the Natural History Museum, London (
Although there is no major difference in scalation between the new species and Gonyosoma prasinum in morphological characters, however, the colorations of the iris of them in life are obviously different. As, furthermore, the new species and G. prasinum have a large genetic divergence, they therefore deserve distinct a distinct status at species level.
Previously, Gonyosoma prasinum has been recorded in India, Bhutan, Myanmar, Thailand, Malaysia, Laos, Vietnam, and China (
Gonyosoma coeruleum sp. nov. is a familiar species in southern Yunnan, China, however, we observed that Gonyosoma coeruleum sp. nov. was often captured and traded as pets due to its beautiful appearance. In order to protect this beautiful species, we suggest that this species to be added to the local protected animal lists and be banned from pet trading.
The field survey in Myanmar was undertaken at the invitation of the Republic of the Union of Myanmar, Ministry of Natural Resources and Environmental Conservation, Forest Department, Forest Research Institute. We thank them for the invitation. Thanks also to the staff and the local guides of Myanmar for their help in the field. This work was supported by Science-Technology Basic Condition Platform from the Ministry of Science and Technology of the People’s Republic of China (Grant No. 2005DKA21402), the project of the second comprehensive scientific investigation of Xishuangbanna National Nature Reserve, and the project of Ministry of Ecology and Environment of China: Investigation and assessment of amphibians and reptiles in Jinghong City, Menghai County, and Mengla County.