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A new species of the genus Kurixalus is described from the Central Highlands of Vietnam based on molecular phylogenetic and morphological analyses. Morphologically, Kurixalus motokawai sp. nov. is most similar to K. banaensis but they are clearly separated from each other in mitochondrial DNA sequences. In phylogenetic analysis the new species clustered in the same clade with Kurixalus banaensis and K. viridescens. However, the new species differs from K. banaensis by having a smaller body size, a higher ratio of forelimb length/SVL in both sexes, a smaller ratio of first toe length/SVL in males, snout tip less markedly pointed, and only weakly developed dermal appendages on the outer edges of fore-and hindlimbs. Kurixalus motokawai sp. nov. also differs from K. viridescens by having a smaller size in females and a brown dorsum with dark markings.
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Nguyen Thien Tao,1Masafumi Matsui,2and Koshiro Eto2,3
Submitted September October 21, 2014.
A new species of the genus Kurixalus is described from the Central Highlands of Vietnam based on molecular
phylogenetic and morphological analyses. Morphologically, Kurixalus motokawai sp. nov. is most similar to
K. banaensis but they are clearly separated from each other in mitochondrial DNA sequences. In phylogenetic
analysis the new species clustered in the same clade with Kurixalus banaensis and K. viridescens. However, the
new species differs from K. banaensis by having a smaller body size, a higher ratio of forelimb length/SVL in
both sexes, a smaller ratio of first toe length/SVL in males, snout tip less markedly pointed, and only weakly
developed dermal appendages on the outer edges of fore- and hindlimbs. Kurixalus motokawai sp. nov. also differs
from K. viridescens by having a smaller size in females and a brown dorsum with dark markings.
Keywords: Kurixalus motokawai sp. nov.; mtDNA phylogeny; taxonomy; Central Highlands; Gia Lai Province;
Kon Tum Province.
The genus Kurixalus Ye, Fei, and Dubois, 1999 has a
restricted range in Asia, from eastern India through
Myanmar and mountainous southern China, southward to
southern Cambodia and central Vietnam, through west-
ern and northern peninsular Thailand to Malaya, Suma-
tra, Borneo, and the Philippines (Frost, 2014). Recent
phylogenetic analyses showed that Kurixalus species are
taxonomically confused (Yu et al., 2010; Li et al., 2013;
Nguyen et al., 2014). From Vietnam, Nguyen et al.
(2009) recorded five species of Kurixalus, viz.
K. ananjevae (Matsui et Orlov), K. baliogaster (Inger,
Orlov, and Darevsky), K. carinensis (Boulenger), K. odo-
ntotarsus (Ye et Fei), and K. verrucosus (Boulenger). Of
these, K. carinensis has been placed in Gracixalus and
Philautus banaensis Bourret was transferred to the genus
Kurixalus (Li et al., 2009). Additionally, Yu et al. (2010)
have suggested that previous records of K. odontotarsus
and K. verrucosus from Vietnam should be assigned to
K. bisacculus. Recently, Nguyen et al. (2014) described
the green Kurixalus form from southern Vietnam as a
new species, namely K. viridescens Nguyen, Matsui et
Hoang. Thus, five Kurixalus species are left being valid
in Vietnam at present, although eight species are listed in
Frost (2014).
During our recent fieldwork in the Central Highlands
of Vietnam, a small tree frog species was collected and
provisionally identified as Kurixalus banaensis. How-
ever, the newly collected specimens have a smaller size
and only weakly pronounced skin ornamentation com-
pared with the latter. Molecular phylogenetic comparison
revealed that they are genetically distinct from each
other. Therefore, we herein describe the tree frog from
Kon Tum and Gia Lai provinces, Vietnam as a new
DNA sequence data from our new samples were
combined with a previously collected mitochondrial se-
quence dataset for species of Kurixalus and relevant
out-groups, including Buergeria japonica and Raorches-
tes gryllus (Li et al., 2013; Nguyen et al., 2014; Table 1).
We used the same methods for DNA extraction, and am-
plification and sequencing of the mtDNA fragments as
those reported by Kuraishi et al. (2013). The resultant
sequences (435 base pairs [bp] of partial sequences of
mitochondrial 16S rRNA gene) were deposited in
GenBank (accession numbers LC 002885 – 002915).
Measurements were taken with digital calipers to the
nearest 0.1 mm. Morphological terminology follows
1026-2296/2014/2104-0295 © 2014 Folium Publishing Company
Russian Journal of Herpetology Vol. 21, No. 4, 2014, pp. 295 – 302
1Department of Nature Conservation, Vietnam National Museum of
Nature, Vietnam Academy of Science and Technology, 18 Hoang
Quoc Viet Road, Hanoi, Vietnam;
2Graduate School of Human and Environmental Studies, Kyoto Uni-
versity, Sakyo, Kyoto 606-8501, Japan;
3Kyoto University Museum, Sakyo, Kyoto 606-8501, Japan;
296 Nguyen Thien Tao et al.
TABLE 1. Sample of Kurixalus sp. and Other Species Used for DNA Analysis in This Study Together with the Information on Voucher, Collection
Locality and GenBank Accession Numbers
Voucher Species GenBank Locality Reference
VNMN 03416 Kurixalus sp. LC002886 Vietnam, Kon Tum This study
VNMN 03457 Kurixalus sp. LC002887 Vietnam, Kon Tum This study
VNMN 03458 Kurixalus sp. LC002888 Vietnam, Kon Tum This study
VNMN 03575 Kurixalus sp. LC002889 Vietnam, Kon Tum This study
VNMN 03576 Kurixalus sp. LC002890 Vietnam, Kon Tum This study
VNMN 03577 Kurixalus sp. LC002891 Vietnam, Kon Tum This study
VNMN 03606 Kurixalus sp. LC002892 Vietnam, Kon Tum This study
VNMN 03722 Kurixalus sp. LC002893 Vietnam, Kon Tum This study
VNMN 03726 Kurixalus sp. LC002894 Vietnam, Kon Tum This study
VNMN 03735 Kurixalus sp. LC002895 Vietnam, Kon Tum This study
VNMN 03739 Kurixalus sp. LC002896 Vietnam, Kon Tum This study
VNMN 03757 Kurixalus sp. LC002897 Vietnam, Kon Tum This study
VNMN 03758 Kurixalus sp. LC002898 Vietnam, Kon Tum This study
VNMN 04006 Kurixalus sp. LC002899 Vietnam, Gia Lai This study
VNMN 04015 Kurixalus sp. LC002900 Vietnam, Kon Tum This study
VNMN 04027 Kurixalus sp. LC002901 Vietnam, Kon Tum This study
VNMN 04028 Kurixalus sp. LC002902 Vietnam, Kon Tum This study
VNMN 03802 Kurixalus viridescens AB933284 Vietnam, Khanh Hoa Nguyen et al. (2014)
VNMN 03813 Kurixalus viridescens AB933285 Vietnam, Khanh Hoa Nguyen et al. (2014)
VNMN 03814 Kurixalus viridescens AB933286 Vietnam, Khanh Hoa Nguyen et al. (2014)
VNMN 03461 Kurixalus banaensis LC002903 Vietnam, Kon Tum This study
VNMN 03909 Kurixalus banaensis LC002904 Vietnam, Kon Tum This study
VNMN 04016 Kurixalus banaensis LC002905 Vietnam, Lam Dong This study
VNMN 04017 Kurixalus banaensis LC002906 Vietnam, Gia Lai This study
VNMN 04018 Kurixalus banaensis LC002907 Vietnam, Binh Phuoc This study
VNMN 04019 Kurixalus banaensis LC002908 Vietnam, Kon Tum This study
VNMN 04020 Kurixalus banaensis LC002909 Vietnam, Kon Tum This study
VNMN 04021 Kurixalus banaensis LC002910 Vietnam, Kon Tum This study
VNMN 04022 Kurixalus banaensis LC002911 Vietnam, Kon Tum This study
VNMN 04023 Kurixalus banaensis LC002912 Vietnam, Kon Tum This study
VNMN 04024 Kurixalus banaensis LC002913 Vietnam, Kon Tum This study
VNMN 04025 Kurixalus banaensis LC002914 Vietnam, Kon Tum This study
VNMN 04026 Kurixalus banaensis LC002915 Vietnam, Kon Tum This study
VNMN 03809 Kurixalus bisacculus AB933295 Vietnam, Thanh Hoa Nguyen et al. (2014)
KUHE 35069 Kurixalus bisacculus AB933291 Thailand, Kanchanaburi Nguyen et al. (2014)
CIB K 2805 Kurixalus bisacculus AB933289 China, Guangxi Nguyen et al. (2014)
VNMN 03618 Kurixalus baliogaster AB933300 Vietnam, Kon Tum Nguyen et al. (2014)
VNMN 03652 Kurixalus baliogaster AB933299 Vietnam, Kon Tum Nguyen et al. (2014)
VNMN 03811 Kurixalus baliogaster AB933297 Vietnam, Gia Lai Nguyen et al. (2014)
KIZ 201307012 Kurixalus odontotarsus AB933302 China, Yunnan Nguyen et al. (2014)
KIZ 201307071 Kurixalus odontotarsus AB933303 China, Yunnan Nguyen et al. (2014)
CAS 231489 Kurixalus verrucosus KC465823 Myanmar, Kachin Li et al. (2013)
RAO 6305 Kurixalus verrucosus KC465825 Cina, Xizang Li et al. (2013)
KUHE 12910 Kurixalus eiffingeri AB933305 Japan, Iriomote Is. Nguyen et al. (2014)
KUHE 12979 Kurixalus idiootocus AB933306 Taiwan, Jiayi Nguyen et al. (2014)
KUHE 53614 Kurixalus appendiculatus AB847125 Borneo, Sarawak Matsui et al. (2014)
KUHE 55238 Raorchestes gryllus AB933309 Vietnam, Tam Dao Nguyen et al. (2014)
RUE 1185 Buergeria japonica LC002885 Japan, Amamioshima This study
Voucher abbreviations: CAS, California Academy of Sciences; CIB, Chengdu Institute of Biology; KIZ, Kunming Institute of Zoology;
KUHE, Graduate School of Human and Environmental Studies, Kyoto University; RAO, field number of Ding-qi Rao; RUE, Faculty of Education,
University of the Ryukyus; VNMN, Vietnam National Museum of Nature.
Matsui (1984, 1994) and Nguyen et al. (2014). The fol-
lowing abbreviations were used: SVL, snout-vent length;
HL, head length; HW, head width; IND, internarial dis-
tance; IOD, interorbital distance; UEW, upper eyelid
width; N-EL, nostril-eye distance; SL, snout length;
EL, eye length; ED, eye diameter; TD, tympanum diame-
ter; T-EL, tympanum-eye length; FLL, forelimb length;
LAL, lower arm and hand length; 1FL, first finger length
(measured from distal edge of inner palmar tubercle);
IPTL, inner palmar tubercle length; HLL, hindlimb
length; HLL, tibia length; FL, foot length; IMTL, inner
metatarsal tubercle length; 1TOEL, first toe length.
Measurements of finger and toe disks in the holotype
were taken to the nearest 0.01 mm using a binocular dis-
secting microscope equipped with a micrometer: first to
fourth finger disk diameter (1 – 4FDW); and first to fifth
toe disk diameter (1 – 5TDW).
Statistical comparisons were made between two
groups separated by molecular analysis. In the univariate
comparisons, SVL was compared by Tukey – Kramer
test, but the remaining characters, converted to ratios to
SVL (R), were compared by Dunn’s multiple compari-
sons test. For description of toe-webbing states we fol-
lowed the system of Savage (1975). Specimens examined
are deposited in the collection of the Vietnam National
Museum of Nature (VNMN), Hanoi, Vietnam.
In our phylogenetic analysis, the undescribed species
of Kurixalux from Vietnam was clustered in the same
group with K. banaensis and K. viridescens, although
their relationships were not resolved (Fig. 2). This group
is a sister clade of the K. verrucosus group, containing
K. verrucosus from southern China and Myanmar,
K. odontotarsus from southern China, K. baliogaster
from Central Highlands of Vietnam and K. bisacculus
from China, Vietnam and Thailand. The specimens of
Kurixalus sp. from Central Highlands exhibited dis-
tinctly large genetic distances from the nine examined
species of Kurixalus with uncorrected p-distance of 8.4 –
17.2% (see Table 2). Whereas, genetic distance (uncor-
A New Kurixalus from Vietnam 297
Fig. 1. Map showing the distribution of Kurixalus motokawai sp. nov.
in Vietnam: 1, Kon Plong in Kon Tum Province (type locality); 2, Dak
Glei in Kon Tum Province; 3, K’Bang in Gia Lai Province.
Fig. 2. ML tree from a 435 bp sequence of mitochondrial 16S rRNA
gene for Kurixalus species and out-groups. ML inferences (ML-BS) >
70% /Bayesian posterior probabilities (BPP) > 95% are shown near the
rected p-distance) between specimens of Kurixalus sp.
from Gia Lai and Kon Tum provinces ranged from 0 to
1.5%. In addition, Kurixalus sp. is also distinguished
from other congeners by some morphological characters.
Thus, we describe the species of Kurixalus from Central
Highlands of Vietnam as a new species as follows:
Kurixalus motokawai sp. nov.
Figs. 3 and 4
Holotype. Adult male VNMN 03458, collected by
Tao Thien Nguyen, at 20:00 on 8 September 2012 in
Mang Canh forest (14°40¢33¢¢ N 108°14¢37¢¢ E, 1230 m
a.s.l.), Kon Plong District, Kon Tum Province, Central
Highlands of Vietnam.
Paratypes. VNMN 03416, 03457, 03557, 03575,
03576, 03577, 03590, 03606, the same data as the
holotype; VNMN 04028 (2012.113), collected by Tao
Thien Nguyen and Chung Van Hoang from 19:00 to
22:00 on 12 October 2012 near Dak Man Ranger Station
(15°12’45¢¢ N 107°44’15¢¢ E, 1150 m a.s.l.), Ngoc Linh
Nature Reserve, Dak Glei District, Kon Tum Province;
VNMN 03574, 04006 (KKK 2012.101), collected by Tao
Thien Nguyen on 23 February 2012 from Kon Ka Kinh
National Park (14°13’23¢¢ N 108°19’15¢¢ E, 1050 m
a.s.l.), K’Bang District, Gia Lai Province.
298 Nguyen Thien Tao et al.
TABLE 2. Uncorrected p-Distances (%) for Fragment of 16S rRNA between Kurixalus and Related Taxa
1Kurixalus sp.
2K. banaensis 8.6 – 9.9
3K. viridescens 9.9 – 11.4 7.6 – 9.4
4K. bisacculus 9.1 – 9.9 10.1 – 11.1 9.1 – 11.1
5K. baliogaster 8.9 – 9.4 8.6 – 10.1 8.4 – 10.9 2.8 – 3.5
6K. odontotarsus 9.4 – 9.9 8.1 – 9.6 8.6 – 11.1 3.8 3.8 – 4.1
7K. verrucossus 8.4 – 10.9 8.6 – 9.6 8.6 – 9.9 6.1 – 6.6 6.1 – 6.3 5.3 – 6.3
8K. idiootocus 10.4 – 10.6 10.1 – 12.2 10.6 – 12.9 10.1 – 11.1 10.1 – 10.4 9.4 8.1 – 9.4
9K. eiffingeri 12.2 – 12.4 10.4 – 11.1 11.1 – 13.2 10.6 – 11.6 9.6 – 9.9 9.6 8.9 – 9.6 5.3
10 K. appendiculatus 16.5 – 17.2 16.7 – 17.7 18.7 – 19.5 18.0 – 19.0 19.0 – 19.2 18.2 16.5 – 17.0 15.9 16.7
11 Raorchestes gryllus 18.0 – 18.5 17.0 – 18.7 17.2 – 17.7 17.5 – 18.5 17.7 – 18.0 18.0 18.5 – 18.5 17.2 14.9 18.5
12 Buergeria japonica 17.5 – 18.2 15.7 – 17.7 19.0 15.4 – 16.2 15.9 – 16.2 16.7 14.7 – 16.7 16.7 15.2 17.0 16.7
Fig. 3. Dorsal (A) and ventral (B) views of the male holotype (VNMN 03458) of Kurixalus motokawai sp. nov. in preservative. Scale bar is
10 mm.
Referred specimens. VNMN 03722, VNMN 03726,
VNMN 03735, VNMN 03739, VNMN 03757, VNMN
03758, VNMN 04015, and VNMN 04027, all from Kon
Tum Province.
Etymology. The species name is dedicated to Asso-
ciate Professor Dr. Masaharu Motokawa from the Kyoto
University, who is an eminent mammalogist and continu-
ously supports the senior author in his study and his
outstanding contribution to biodiversity research in
Diagnosis. The new species was assigned to the ge-
nus Kurixalus by a combination of the following mor-
phological characters: small-sized rhacophorid (SVL <
50 mm); tips of digits enlarged to the discs, bearing cir-
cummarginal grooves; snout tip pointed; finger webbing
poorly developed; dermal fringes present on forearm and
tarsus (Bourret, 1939; Taylor, 1962, Matsui and Orlov,
2004, Yu et al, 2010). The new species is unambiguously
nested in the genus Kurixalus by molecular phylogenetic
evidence, closely related to K. banaensis and K. viride-
scens. The specimens from Central Highlands differ from
K. viridescens by the color pattern and body size and
from K. banaensis by having a smaller size and weakly
developed skin ornamentations.
Description of holotype. SVL 27.8 mm; body mod-
erately robust; head as long as wide (HL 10.8 mm, HW
10.8 mm, 38.8% of SVL); snout (SL 4.2 mm, 15.1% of
SVL) shorter than eye (EL 4.5 mm, 16.2% of SVL), dor-
sally pointed at tip, sloping anteroventrally in profile,
projecting over lower jaw; canthus slightly blunt; loreal
region oblique, concave; nostril protuberant, closer to the
tip of snout than to eye; internarial distance (IND
3.0 mm, 10.8% of SVL) as wide as interorbital (IOD
3.0 mm, 10.8% of SVL); narrower than upper eyelid
(UEW 3.2 mm, 11.5% of SVL); pineal spot present; eye
large, protuberant, diameter (ED 3.8 mm, 13.7% of SVL)
much larger than nostril-eye distance (N-EL 1.8 mm,
6.5% of SVL); pupil horizontal; tympanum distinct,
subcircular, its diameter (TD 1.7 mm, 6.1% of SVL) less
than half eye diameter and separated from eye by one-
third of tympanum diameter (E-TL 0.6 mm, 2.2% of
SVL); vomerine teeth absent; tongue deeply notched
Forelimb moderate (FLL 18.1 mm, 65.1% of SVL);
relative finger lengthsI<II<IV<III; length of first fin-
ger (1FL 2.4 mm, 8.6% of SVL) much shorter than diam-
eter of eye; tips of all fingers dilated into horizontally
elongate large disks with circummarginal and transverse
ventral grooves; third and fourth finger disks (3FDW
1.1 mm, 3.8% of SVL; 4FDW 1.1mm, 4.0% of SVL) nar-
rower than tympanum diameter; fingers with poorly de-
veloped webbing, formula I2 – 23/4II2–2
2IV; fringe of skin on edge of fingers; subarticular tuber-
cles distinct, rounded, formula 1, 1, 2, 2; supernumerary
tubercles on metacarpal absent; prepollex prominent,
oval; inner palmar tubercle distinct (IPTL 2.1 mm, 7.6%
SVL), outer palmar tubercles two, small.
Hindlimb long (HLL 42.6, 153.2% SVL), about 2.4
times length of forelimb; tibia not long (TL 13.8, 49.6%
SVL), heels overlapping when limbs are held at right an-
gles to body; tibiotarsal articulation of adpressed limb
reaching middle of eye; foot (FL 10.6, 38.1% SVL)
shorter than tibia; relative length of toesI<II<III<V<
IV; tips of toes expanded into round disks with distinct
circummarginal grooves, subequal to those of fingers
(3TDW 1.1 mm, 3.9% of SVL; 4TDW 1.1 mm, 4.0% of
SVL; 5TDW 1.0 mm, 3.7% of SVL); toe webbing mod-
erately developed, formula I2 – 2II1/3– 2III1 –
1/2V; subarticular tubercles distinct,
rounded, formula 1, 1, 2, 3, 2; supernumerary tubercles
absent; inner metatarsal tubercle distinct, oval (IMTL
1.3 mm, 4.7% of SVL), about half length of first toe
(1TOEL 2.7 mm, 9.7% of SVL); outer metatarsal tu-
bercle absent.
Skin. Dorsum with sparsely distributed small tu-
bercles; supratympanic fold distinct, running from eye
above tympanum, ending at above arm insertion; lateral
sides and abdomen areolate; a weakly developed ridge of
skin on outer edge of forearm forming a weak serration;
hindlimb smooth, except for a weak serration along outer
edge of tarsus and fifth toe; tubercles including two pairs
of large conical ones posteroventral to cloaca; heel with
small triangle dermal appendage.
A New Kurixalus from Vietnam 299
Fig. 4. Dorsal views of right hand (A) and foot (B) of the male
holotype (VNMN 03458) of Kurixalus motokawai sp. nov. in preserva-
tive. Scale bar is 5 mm.
Coloration. In preservative, ground color of head
and body grayish brown with large dark brown marking
except for upper eyelid, shoulder, and post-sacral re-
gions. Lateral head and tympanic region grayish brown
with a dark bar below canthus. Limbs dorsally grayish
brown with dark brown marking, forming crossbars on
lower arm, tibia, and tarsus. Ventral surface white, scat-
tered with dark brown spots on chin, lower part of flanks,
and limbs except for thigh. Rear of thigh mottled with
dark spots. Infra-cloacal region white. Hand and foot
ventrally grayish brown scattered with dark spots.
Variation. Morphometric data are summarized in
Table 3. Because only one female was available, sexual
dimorphism could not be determined statistically, but a
single female has the size (SVL 25.1 mm) within the
variation range of males (23.2 – 28.4 mm, mean 26.1 ±
1.46 mm). In some paratypes, head is wider than long,
IND is smaller than IOD, and IOD is smaller than UEW
(2 specimens). The tibiotarsal articulation reaches the
center of the eye (9 specimens), to anterior corner of the
eye (6 specimens), or to between eye and nostril (1 speci-
men). Some individuals have conical dermal appendage
at the snout and/or heel. Coloration in life is variable,
some individuals have a dorsum tinged with green (see
Fig. 5).
Comparisons. The new species, K. motokawai sp.
nov., is morphologically similar to K. banaensis, but they
can be distinguished from each other in the body size.
The males of K. motokawai sp. nov. are smaller than
those of K. banaensis (SVL 23.2 – 28.4 mm, mean ± SD
26.1 ± 1.46 mm, versus 26.2 – 33.2 mm, mean ± SD
29.7 ± 2.43 mm, Tukey – Kramer test, P< 0.01) (see
Tables 4 and 5). In terms of proportions, K. motokawai
has a higher value of RFLL in both sexes (ratio of fore-
limb length/SVL) but smaller value of R1TOEL in males
(ratio of first toe length/SVL) (Dunn’s multiple compari-
son test, P< 0.05) (see Table 6). These species also differ
from each other in the shape of the snout tip and the
dermal appendage at cloaca (snout tip less markedly
pointed and lateral fringes on limbs and infra-cloacal
tubercles less developed in K. motokawai sp. nov. than
in K. banaensis).
The new species differs from K. viridescens by hav-
ing a smaller size in females (SVL 25 mm vs. 29
37 mm in K. viridescens) and a brown dorsum with dark
markings (vs. green dorsum without markings in K. viri-
descens); from K. ananjevae (Matsui and Orlov, 2004) by
having a smaller size (male SVL 23 – 28 mm, female
SVL 25 mm vs. male 32 mm, female 43 mm in
K. ananjevae) and the presence of dermal ornamentations
(absent in K. ananjevae); from K. appendiculatus (Gün-
300 Nguyen Thien Tao et al.
TABLE 3. Measurements of adult specimens of Kurixalus motokawai sp. nov. and K. banaensis
K. motokawai K. banaensis
17 x1}6x4}
SVL 26.1 ± 1.46 (23.2 – 28.4) 25.1 29.7 ± 2.43 (26.2 – 33.2) 33.9 ± 2.71 (30.5 – 37.0)
RHL 39.8 (36.4 – 42.4) 41.4 40.1 (39.2 – 41.6) 38.8 (37.7 – 42.5)
RHW 40.5 (36.4 – 44.2) 40.2 41.0 (37.5 – 42.4) 39.1 (37.0 – 42.8)
RIND 10.2 (8.8 – 11.7) 11.6 10.1 (9.6 – 10.7) 10.2 (8.1 – 11.0)
RIOD 12.0 (10.8 – 14.1) 12.7 11.3 (10.3 – 13.4) 11.0 (9.8 – 12.1)
RUEW 11.3 (8.8 – 13.4) 11.6 11.8 (8.8 – 13.0) 11.2 (11.1 – 11.5)
RSL 15.6 (13.8 – 17.4) 16.3 15.8 (14.7 – 17.8) 15.0 (14.3 – 15.6)
RN-EL 8.4 (6.5 – 10.9) 8.8 9.2 (8.0 – 11.1) 8.6 (7.5 – 9.0)
REL 17.1 (15.3 – 20.3) 18.3 17.2 (16.8 – 18.4) 16.1 (14.6 – 17.4)
RED 14.7 (13.7 – 15.3) 14.7 14.5 (14.1 – 15.7) 13.8 (13.8 – 13.8)
RTD 6.1 (4.5 – 7.1) 6.4 5.8 (5.6 – 6.6) 6.1 (5.2 – 7.5)
RE-TL 1.5 (0.7 – 2.4) 2.0 1.4 (1.1 – 1.6) 1.7 (0.9 – 2.0)
RLAL 49.3 (46.8 – 54.7) 47.0 48.7 (44.2 – 49.8) 46.5 (45.1 – 49.2)
RFLL 65.1 (61.6 – 70.3) 62.5 60.7 (59.1 – 63.6) 59.6 (58.9 – 60.5)
RIPL 5.8 (4.1 – 7.6) 6.4 5.3 (4.0 – 6.3) 4.8 (4.3 – 5.6)
R1FL 8.4 (7.6 – 9.9) 8.8 8.7 (8.0 – 12.8) 9.2 (7.8 – 10.2)
RTL 49.3 (45.5 – 52.8) 50.2 50.4 (44.9 – 51.6) 50.5 (47.0 – 55.4)
RFL 40.2 (37.7 – 51.6) 39.4 42.5 (38.5 – 44.9) 41.9 (35.4 – 43.3)
RHLL 152.0 (144.0 – 161.8) 155.4 157.2 (136.1 – 166.7) 156.2 (142.2 – 165.0)
RIMTL 4.6 (3.0 – 5.7) 6.0 4.8 (3.7 – 5.8) 5.4 (4.3 – 5.9)
R1TOEL 8.2 (7.3 – 10.3) 8.0 9.5 (9.0 – 11.6) 8.4 (8.1 – 10.8)
Notes. SVL (mean ± SD, in mm) and medians of percentage ratios (R) of other characters to SVL, followed by ranges in parenthesis. See text for char-
acter abbreviations.
ther) in having a smaller size in males (SVL 23 – 28 mm
vs. 30 – 37 mm), infra-cloacal appendage with several
conical tubercles (vs. dermal flap), and vomerine teeth
absent (vs. present in K. appendiculatus); from K.
baliogaster by having a smaller size in males (SVL
23 – 28 mm vs. 33 mm), ventral surface scattered with
small dark spots and lacking a rostral cone in females (vs.
ventral surface with conspicuous, large black spots, fe-
males with a strong rostral cone in K. baliogaster); from
K. bisacculus by having a smaller size in females (SVL
25 mm vs. 29 mm), belly immaculate white (vs. belly
with black spots), and vomerine teeth absent (vs. present
in K. bisacculus).
The new species differs from K. eiffingeri (Boettger)
by having a smaller size (male SVL 23 – 28 mm vs.
31 – 35 mm and female SVL 25 mm vs. 32 – 44 mm)
and serrated lateral skin on lower arm, tibia, and tarsus
(vs. lateral skin with a row of tubercles in K. eiffingeri);
from K. idiootocus (Kuramoto et Wang) by the presence
of serrated dermal fringe on lower arm, tibia, and tarsus;
from K. naso (Annandale), K. motokawai differs by body
size, snout shape, toe webbing, and ventral color (male
SVL 23 – 28 mm and female SVL 25 mm, snout tip
weakly pointed, toe webbing poorly developed, and ven-
tral surface scattered with small dark spots vs. SVL
43 mm, snout with a cone, toe webbing well-developed,
and chin and breast marked with dark reticulation in
K. naso); from K. odontotarsus by having a smaller size
(male SVL 23 – 28 mm and female 25 mm vs. 30 –
33 mm and 35 – 43 mm, respectively), snout weakly
pointed (vs. sharply pointed), and ventral surface scat-
tered with small dark spots (vs., venter with large dark
markings in K. odontotarsus); from K. verrucosus by
having smaller size in female (SVL 25 mm vs. 43
45 mm), belly without dark spots (vs. present), and toe
webbing moderately developed (well developed in
K. verrucosus).
Distribution. K. motokawai is currently known from
several localities in the Central Highlands of Vietnam:
Kon Plong forest and Ngoc Linh Nature Reserve in Kon
Tum Province, and Kon Ka Kinh National Park in
K’Bang District, Gia Lai Province, at elevations from
1050 m to 1230 m a.s.l.
Natural history. Surrounding habitat at the type lo-
cality of the species in Kon Plong District, Kon Tum
Province was the primary rain-forest, inclined slopes of
the mountains at elevations of 1100 – 1400 m a.s.l. All
specimens were collected at night, from 19:00 to 23:00.
The specimens were found on leaves of scrub vegetation
and young trees, about 0.5–1mabove the ground. Asso-
ciated species observed at the type locality were Gracixa-
lus supercornutus (Orlov, Ho et Nguyen), Raorchestes
gryllus (Smith) and Rhacophorus robertingeri Orlov,
Poyarkov, Vassilieva, Ananjeva, Nguyen, Nguyen et
A New Kurixalus from Vietnam 301
Fig. 5. Male paratype (VNMN 04006) of Kurixalus motokawai sp.
nov. in life.
TABLE 4. Comparison of the size (average SVL) between Kurixalus
motokawai sp. nov. and K. banaensis
Species NMean Standard
1. Kurixalus motokawai (x)17 26.017 1.465
2. Kurixalus banaensis (x)6 29.683 2.428
3. Kurixalus banaensis (})4 33.900 2.712
Total 27 28.033 3.427
TABLE 5. One way ANOVA Test and Tukey – Kramer Test of the Size (Average SVL) between Kurixalus motokawai sp. nov. and K. banaensis
Comparison Difference SE qConclusion
Kurixalus banaensis (}) vs. K. motokawai (x)7.829 0.743 10.534* K. banaensis (})>K. motokawai (x)
K. banaensis (}) vs. K. banaensis (x)4.217 0.863 4.884* K. banaensis (})>K. banaensis (x)
K. banaensis (x) vs. K. motokawai (x)3.613 0.635 5.688* K. banaensis (x)K. motokawai (x)
Notes. One way ANOVA test: df = 2.24, F= 30.6760, p= 0.0000; Tukey – Kramer test: if q>q(0.05, 3, 24) = 3.532, then significant (*), else not
Generally, small rhacophorids with brown dorsum
are difficult to identify and identification should be ide-
ally made with reference to type specimens. Kurixalus
motokawai has been confused with K. banaensis for a
long time (e.g., Nguyen et al., 2009). Kurixalus banaen-
sis was originally described by Bourret (1939) in the
genus Philautus from Bana (= Ba Na, Da Nang City,
Vietnam). In the Muséum national d’Histoire naturelle
(MNHN) in Paris, currently three syntypes (MNHN
1948.0159 – 0161) are deposited, together with a topo-
type (MNHN 1948.0162). Bossuyt and Dubois (2001)
designated the lectotype (MNHN 1948.0160) and pro-
vided a redescription of this species. Our examination of
the lectotype revealed some additional characters for the
original description of Bourret (1939): snout clearly
pointed; canthus distinct; tympanum indistinct; webbing
between second and third fingers, and third and fourth
fingers not rudimentary; dermal fringe on side of upper
arm and tarsus serrated; triangular skin projections pres-
ent below cloaca; interorbital with dark markings. Fur-
thermore, the topotype has a pineal spot and round snout,
and toe webbing formula of I11/2– 2II11/3– 2III11/2
1/2V. In our molecular analyses, the new spe-
cies, K. viridescens, and K. banaensis tended to form a
group, which we propose to call the K. banaensis species
group. Because the new species and K. banaensis are su-
perficially similar, previous records of K. banaensis in
Vietnam need to be verified by further studies. Finally,
comparison of advertisement calls may help to elucidate
bioacoustic differences between K. motokawai and
K. banaensis.
Acknowledgments. We thank the directorates of the Forest
Protection Departments of Kon Tum and Gia Lai provinces,
Ngoc Linh Nature Reserve and Kon Ka Kinh National Park for
issuing relevant permits and support of our fieldwork.
T. T. Nguyen thanks C. V. Hoang (Hanoi), Y. Kawahara and
N. Kuraishi (Kyoto) for field and laboratory assistance.
M. Matsui thanks A. Dubois and A. Ohler (Paris) for allowing
him to examine specimens under their care. We thank T. Ziegler
(Cologne) and N. L. Orlov (Saint Petersburg) for their helpful
comments. Thanks to E. Sterling (New York) and Kevin Koy
(Berkeley) for providing the map. Field work was partly sup-
ported by the Project TN3/T07 of the National Program Tay
Nguyen III and STMVQG. 06/14-16 to T. T. Nguyen, the grant
from the Japan Society for the Promotion of Science (JSPS AA
Science platform Program, FY2011 – 2013) to M. Motokawa,
Grants-in Aid from the Monbusho through the Japan Society
for the Promotion of Science (Field Research, Nos. 15370038,
20405013 and 23405014) to M. Matsui. Research of
T. T. Nguyen in Japan is funded by the JSPS RONPAKU Pro-
gram (VAST-11224).
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302 Nguyen Thien Tao et al.
... Photo by Tan Van Nguyen. for DNA identification of cryptic diversity within the genus Kurixalus by previous authors (Nguyen et al. 2014a(Nguyen et al. , 2014bWu et al. 2016;Yu et al. 2017aYu et al. , 2017bYu et al. , 2018Lv et al. 2018). A 16S rRNA-gene fragment was amplified using ScreenMix-HS (Evrogen, Russia) following the manufacturers' instructions. ...
... We compared morphological characters of the new species with other members of the genera Kurixalus and Gracixalus; comparative data were obtained from original descriptions and taxonomic revisions of the group (e.g. Boulenger 1893;Smith 1924;Inger 1954;Taylor 1962;Hu et al. 1978;Ye and Hu 1984;Kuramoto and Wang 1987;Inger et al. 1999;Bossuyt and Dubois 2001;Bain and Nguyen 2004;Matsui and Orlov 2004;Orlov et al. 2004;Zhao et al. 2005;Nguyen et al. 2008Nguyen et al. , 2013Nguyen et al. 2014aNguyen et al. , 2014bFei et al. 2009;Rowley et al. 2011Rowley et al. , 2014Mo et al. 2013;Luu et al. 2014;Matsui et al. 2015Matsui et al. , 2017Wu et al. 2016;Egert et al. 2017;Zeng et al. 2017;Yu et al. 2017aYu et al. , 2017bYu et al. , 2018Yu et al. , 2019Wang et al. 2018;Chen et al. 2018a;Pham et al. 2019;Yi and Sheridan 2019). ...
... nov. Morphological diagnostics in Kurixalus are complicated (Yu et al. 2013(Yu et al. , 2017bNguyen et al. 2014b), and many members can easily be confused with other Rhacophorid genera. While K. gracilloides sp. ...
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We describe a new species of rhacophorid frogs from Nghe An Province in northern Vietnam based on morphological and molecular evidences. Morphologically, Kurixalus gracilloides sp. nov. is distinguished from its congeners by a combination of the following diagnostic characters: body size small (snout–vent length 27.9–31.2 mm in males); head width subequal to head length; snout rounded with no dermal projection; canthus rostralis distinct, curved; vomerine teeth present; single internal vocal sac; iris golden-brown; small nuptial pad in finger I; dorsal surfaces golden-brown with a saddle-shaped dark marking; large dark spots on ventral surfaces absent; dermal fringes along outer edge of limbs; conical dermal appendage at the heel; skin on dorsum rough; skin on throat and chest granular; finger webbing rudimentary and toe webbing moderately developed, webbing formula I 2–2½ II 1½–3 III 1¾–3½ IV 3–1½ V. The new species is separated from all other congeners by uncorrected genetic distances ranging from 5.4% to 12.7% based on mitochondrial 16S rRNA gene. Phylogenetic analyses of mtDNA suggest that the new species is nested within a clade of Taiwanese and Yunnan Kurixalus with strong support values. The new species is currently known only from secondary bamboo forest in Pu Mat National Park, northern Vietnam, at elevations of 150 m asl. We suggest the new species should be considered as Near Threatened (NT) following the IUCN’s Red List categories.
... Diagnosis. The new tree frog species is assigned to the genus Kurixalus based on a combination of the following characters: tips of digits enlarged to discs, bearing circum-marginal grooves; small body size (SVL range of 31.6-34.7 mm in adult males; Table 1); finger webbing poorly developed and toe webbing moderately developed; ser rated dermal fringes along outer edge of forearm and tarsus; an inverted triangularshaped dark brown mark between eyes; dorsal brown ") (" saddle-shaped marking; and coarse dorsal and lateral surfaces with small, irregular tubercles (Nguyen et al. 2014a, Nguyen et al. 2014b, Yu et al. 2017b). Our previous molecular study placed the new species in Kurixalus with other known congeners (Yu et al. 2017a). ...
... Taxonomic confusion in the K. odontotarsus species group mainly involved K. bisacculus. Of the remaining five clades that might represent unnamed species, four (clades F, G, H, and K; Fig. 1) were placed in K. bisacculus (Stuart and Emmett 2006, Thy et al. 2010, Yu et al. 2010, Nguyen et al. 2014a, Nguyen et al. 2014b). Even K. hainanus (clade J) was considered a synonym of K. bisacculus (Yu et al. 2010). ...
... A reason for this situation is the relatively low divergence of 16S rRNA sequences between K. bisacculus and these clades, which resulted in these lineages being considered conspecific though morphological differences exist between them (e.g., Yu et al. 2010). Another source of taxonomic confusion in the K. odontotarsus species group involves K. verrucosus, as specimens from northern Myanmar (Kurixalus sp5; Fig. 1) and Kurixalus naso from southern Tibet (clade A, Fig. 1) had been wrongly treated as K. verrucosus in previous molecular studies (Yu et al. 2010, Yu et al. 2013, Li et al. 2013, Nguyen et al. 2014a, Nguyen et al. 2014b) according to Yu et al. (2017a). Additionally, with the exceptions of those unnamed lineages revealed by Yu et al. (2017a), cryptic species likely also exist in Philippine populations of K. appendiculatus according to Gonzalez et al. (2014). ...
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A new species of the genus Kurixalus (Anura: Rhacophoridae) is described from western Yunnan, China. Genetically the new species, Kurixalusyangisp. n. , is closer to Kurixalusnaso than to other known congeners. Morphologically the new species is distinguished from all other known congeners by a combination of the following characters: smaller ratios of head, snout, limbs, IND, and UEW to body size; male body size larger than 30 mm; curved canthus rostralis; weak nuptial pad; brown dorsal color; absence of large dark spots on surface of upper-middle abdomen; presence of vomerine teeth; gold brown iris; single internal vocal sac; serrated dermal fringes along outer edge of limbs; granular throat and chest; rudimentary web between fingers; and presence of supernumerary tubercles and outer metacarpal tubercle.
... material 1: Table S4): K. berylliniris, K. wangi, K. idiootocus, K. eiffingeri, K. bisacculus, K. lenquanensis, K. odontotarsus. K. yangi, K. naso, K. viridescens and K. ananjevae (Kuramoto and Wang 1987;Matsui and Orlov 2004;Nguyen et al. 2014;Tao et al. 2014;Wu et al. 2016;Yu et al. 2017b;Yu et al. 2018;Zeng et al. 2021). The data were, however, incomplete for the variables TEY, TFL, THL, HND and RAD and these variables were removed from the analyses. ...
... The description of advertisement calls of five Kurixalus species. (Kuramoto and Wang 1987;Matsui and Orlov 2004;Tao et al. 2014;Wu et al. 2016;Yu et al. 2017b;Yu et al. 2018;Zeng et al. 2021). Figure S1. ...
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Knowledge of biodiversity before species become extinct is paramount to conservation, especially when the relevant species are far from their expected distribution and, thus, likely overlooked. Here, we describe a new Kurixalus species corresponding to a range extension of Kurixalus on the Asian mainland, with the closest population in Taiwan. The species diverged from its closest relative during the Late Pliocene to Pleistocene, ca. 3.06 Mya (HPD 95%: 5.82-0.01), based on calibrations with a relaxed clock species tree of unlinked mtDNA 12S rRNA and nuclear DNA TYR. The status of the newly-described species is also supported by a divergence in call properties and morphometrics. We named the species described here as Kurixalus inexpectatus sp. nov. due to the nature of the discovery, as well as the adjunct distribution of the species relative to its closest congeners. The species was found in Zhejiang Province and it represents a range extension of 663 km for the Kurixalus genus.
... Frogs of genus Kurixalus Ye, Fei, and Dubois, 1999 (Frilled Swamp Treefrogs) are distributed from east to south Asia, include the countries of Cambodia, China, India, Indonesia, Japan, Laos, Malaysia, Myanmar, Philippine, Thailand and Vietnam. Now this genus contains 20 species including K. absconditus Mediyansyah, Hamidy, Munir, and Matsui, 2019, K. appendiculatus (Günther, 1858), K. baliogaster (Inger et al., 1999), K. banaensis (Bourret, 1939), K. berylliniris Wu, Huang, Tsai, Li, Jhang, and Wu, 2016, K. bisacculus (Taylor, 1962), K. chaseni (Smith, 1924), K. eiffingeri (Boettger, 1895), K. gracilloides (Nguyen et al., 2020), K. hainanus (Zhao et al., 2005), K. idiootocus (Kuramoto and Wang, 1987), K. lenquanensis (Yu et al., 2017a), K. motokawai (Nguyen et al., 2014b,) K. naso (Annandale, 1912), K. odontotarsus (Ye et al., 1993), K. raoi (Zeng et al., 2021), K. verrucosus (Boulenger, 1893), K. viridescens (Nguyen et al., 2014a), K. wangi (Wu et al., 2016), K. yangi (Yu et al., 2018) (Frost, 2021) Currently a total of 11 species of Kurixalus are known in China, including K. berylliniris, K. eiffingeri, K. hainanus, K. idiootocus, K. lenquanensis, K. naso, K. odontotarsus, K. raoi, K. verrucosus, K. wangi and K. yangi. They are ranged from Taiwan southeastward and westward to Hainan, Guangdong, Guangxi, Guizhou, Yunnan and Tibet (, ...
... Comparative morphological data of other Kurixalus species were obtained from previous publications (Yu et al., 2017a;Yu et al., 2018;Zeng et al., 2021;Nguyen et al., 2014a;Nguyen et al., 2014b;Nguyen et al., 2020;Wu et al., 2016;Inger et al., 1999;Taylor, 1962;Mediyansyah et al., 2019;Zhao et al., 2005). ...
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Eight specimens of frilled swamp tree frogs of Genus Kurixalus were collected from Pingle Town, Qionglai County, Chengdu Prefecture, Sichuan Province, China in April to May 2020. Based on morphological and molecular evidence, we describe these specimens as a new species of Kurixalus. Kurixalus silvaenaias sp. Nov., which are similar to K. idiootocus in appearance and phylogenetically are sister to each other, but morphologically the former can be distinguished from K. idiootocus and other congeners by the following combination of characters: body size 29.6-32.9 mm in males; single internal vocal sac; snout obtuse and rounded with no obvious dermal prominence on tip; vomerine teeth present; nuptial pads less developed, present on the base of first finger in males; throat coarsely granulated; tuberculated dorsal and lateral skin; outer metacarpal tubercles present; dorsal surface yellowish brown with a large hourglass shaped dark brown marking and without any green speckles; pair of large symmetrical dark blotches on chest; and abdomen dark purple. The new species is the first record of Kurixalus in Sichuan, China.
... Morphological terminology followed Fei et al. (2017) (Supplementary Materials and Methods). Comparative morphological data of other Kurixalus species were taken from previous publications (Annandale, 1912;Bossuyt & Dubois, 2001;Boulenger, 1893;Günther, 1858;Inger et al., 1999;Kuramoto & Wang, 1987;Mediyansyah et al., 2019;Nguyen et al., 2014aNguyen et al., , 2014bSmith, 1924;Taylor, 1962;Van Nguyen et al., 2020;Wu et al., 2016;Yu et al., 2017bYu et al., , 2018Zhao et al., 2005). Multivariate principal component analysis (PCA) was conducted using SPSS 17.0 (SPSS Inc., USA) based on a correlation matrix of size-standardized measurements (all measurements divided by SVL). ...
... The species name is dedicated to Dr. Ding-Qi Rao from the Kunming Institute of Zoology, Chinese Academy of Sciences, for his support of our research over the years. Diagnosis: The new tree frog species is assigned to Kurixalus based on the following characters: small body size (SVL<50 mm); finger webbing poorly developed and toe webbing moderately developed; serrated dermal fringes along outer edge of forearm and tarsus; inverted triangle-shaped dark brown mark between eyes; dorsal brown ") (" saddle-shaped marking; coarse dorsal and lateral surface with tubercles (Nguyen et al., 2014a(Nguyen et al., , 2014bYu et al., 2017bYu et al., , 2018. Phylogenetic analysis supported that the new species belongs to the genus Kurixalus and is sister to K. idiootocus ( Figure 1C). ...
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We describe a new species of the genus Kurixalus, Kurixalus raoi sp. nov., from Guizhou Province, China, based on morphological and molecular evidence. Phylogenetically, the new species is sister to K. idiootocus, but is distinguishable from all known congeners by a combination of the following characters: small body size (snout-vent length 28.2‒32.2 mm in males; 38.6 mm in female); snout rounded, with no prominence on tip; single internal vocal sac; dorsal surface brown, rough, scattered with several small warts; chin clouded with blackish marking; pair of large symmetrical dark blotches on chest; vomerine teeth present; iris brown; tibiotarsal articulation reaching center of eye; nuptial pad slight; flank rough; mandibular symphysis weak; throat skin granular; and toes moderately webbed, formula I2‒2II1.5‒3III2‒3IV3‒2V. The genetic distances between the new species and K. idiootocus were 2.9% and 5.4% for 16S rRNA and COI, respectively.
... Currently, K. odontotarsus is known to be distributed in southeastern Yunnan, China; Sepian, Boloven Highlands, Champasak Province, Laos; Lao Cai and Ha Giang Provinces, Vietnam (Frost, 2020). The rhacophorid genus Kurixalus currently includes 19 species, mainly distributed in India, China, Indochina, Malaysia, and Philippines (Nguyen et al., 2014a;Lv et al., 2018;Yu et al., 2018;Frost, 2020). Taylor (1962) described K. bisacculus that collected from type locality (Phu Kading, Loei Province, Thailand), which also represented the first record of the genus Kurixalus from this country. ...
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Thailand is a global biodiversity hotspot, harboring a striking diversity of species and endemism. However, the amphibian diversity in the region is poorly understood. In this study, the frogs Kurixalus odontotarsus and Raorchestes longchuanensis were collected and recorded for the first time in northern Thailand. This determination was based on specimens previously collected from this region. Morphologically, these specimens displayed good agreement with the original descriptions provided for K. odontotarsus and R. longchuanensis. Phylogenetically, the specimens clustered according to the sequences of type locality of K. odontotarsus and R. longchuanensis with only a small degree of genetic distance. Based on our work, we have extended the latitudinal distribution of K. odontotarsus and R. longchuanensis southward into northern Thailand. Notably, our discovery increases the number of amphibian species recorded in Thailand to 195, and the number of rhacophorid species known to occur in Thailand to 40.
... Kurixalus is a monophyletic genus of rhacophorid frogs (mainly tree dwellers) whose sixteen constituent species inhabit a broad swath encompassing the eastern Himalayas, Myanmar, Indochina, southern China, Sundaland, the Philippines, Taiwan, and Japan's Ryukyu islands. Recently, Lv et al. (2018) presented a dated molecular phylogeny for the group based on a synthesis of sub-regionally focused investigations (Frost et al., 2006;Li et al., 2008Li et al., , 2009Li et al., , 2013Yu et al., 2010Yu et al., , 2013Rowley et al., 2011;Hertwig et al., 2013;Nguyen et al., 2014aNguyen et al., , 2014b. Following their analysis, Lv et al. (2018) proposed that the genus originated in southern Indochina-Taiwan c. 36.8 ...
Geological data indicate that the interpretation for the age-calibrated phylogeny for the Kurixalus-genus frogs of South, Southeast and East Asia (Lv et al., 2018) needs to be rethought A B S T R A C T Recently, Lv et al. (2018) published an age-calibrated phylogenetic tree for the Kurixalus frogs, members of which occur across parts of South, Southeast and East Asia. A clade on Taiwan, represented by Kurixalus idiootocus and the Kurixalus eiffingeri species complex, is deemed to have been resident since the middle Cenozoic; its closest congeners are in southern Indochina (not in the adjacent parts of southeast China), and the split between the two is dated at 32.8 Ma. Furthermore, a sub-population of Kurixalus eiffingeri is believed to have colonized islands in the western Ryukyus c. 13.5 Ma. There is, however, a problem with this scenario: the landmass regarded as modern-day Taiwan has existed only for 4-5 million years (it results from a young and ongoing tectonic-plate collision). Assuming the Kurixalus phylogeny and the dating of its branchings are correct, then a palaeobiogeographical scenario involving an older, alternative land surface with later transfer to Taiwan, possibly involving over-water dispersal, would reconcile the biology, but testing this may be difficult/im-possible. If the ages of the nodes in the proposed tree are found to be significantly overestimated, the geology and biology might more easily be accommodated.
... The new species is assigned to the genus K urixalus based on molecular analysis, and following morphological characters: a small-sized rhacophorid (SVL<50 mm); tips of fingers dilated into round disks having circummarginal grooves; snout tip pointed; finger webbing poorly developed; toe webbing moderately developed; dermal fringes present on forearm and tarsus; narrow flap on heel and crenulate dermal projection on vent; dorsum brown with saddle-shaped or X-shaped marking (Nguyen et al., 2014a;Yu et al., 2017bYu et al., , 2018. Kurixalus absconditus sp. ...
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Kurixalus absconditus sp. nov., a new species of tree frog of the genus Kurixalus, described from West Kalimantan on the basis of molecular phylogenetic and morphological evidence. The new species can be distinguished from its congeners by a combination of following morphological characters: having smaller body size, more prominent of mandibular symphysis, skin smooth on throat, vomerine odontophores two oblique series touching anterior corner of choanae and widely separated, vomerine teeth thick, buccal cavity narrow and deep, choanae with teardrop shaped, single vocal slit, weakly crenulated dermal fringe on fore-and hindlimbs.
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The Indochinese Peninsula is recognized as one of the key global biodiversity hotspots. The amphibian fauna of Indochina (including Vietnam, Laos, Cambodia and Thailand) is one of the richest in the world. About 60% of the known species were described within the last 20 years. We review the literature and our data to assess all recent discoveries and taxonomic changes and compile the first annotated checklist of the amphibian fauna of Indochina since the middle of the 20th century, including updated faunal lists for Vietnam and Thailand. Amphibian checklists for Laos and Cambodia are published for the first time. For each species we provide the following information: scientific name; recommended common name in English; information on type specimens; type locality; data on its distribution within Indochina and beyond; IUCN conservation status; taxonomic comment and the most important references. We review the distribution of each species across the 23 biogeographic subregions of Indochina, estimate the similarity among the regional faunas and evaluate their species richness and endemism. In total we record 423 amphibian species belonging to three orders, 11 families and 71 genera; 199 species (47%) are endemic to Indochina. Comprising 270 known species, the amphibian fauna of Vietnam is the richest (98 endemics, 36.3%), followed by Thailand with 194 species (29 endemics, 14.9%), Laos with 121 species (13 endemics, 10.7%), and Cambodia with 72 species (6 endemics, 8.3%). A cluster analysis of faunal similarity between the subregions shows two major assemblages, divided by the Isthmus of Kra. Within the northern mainland portion of Indochina three clusters can be distinguished: (1) northeastern and northwestern uplands of Vietnam and northern Laos; (2) Northern, Central, and Southern Annamites, the Bolaven Plateau, and central-south Vietnam lowlands; (3) western Indochinese subregions. We identify the Northeast and Northwest Uplands of Vietnam, the Northern, Central and Southern Annamites, the Cardamom Mountains, the mountains of Northeast Thailand, Northern Tenasserim and southern Peninsular Thailand as nine major centers of diversity and endemism of Indochinese amphibians. The analysis of amphibian distribution patterns across Indochina suggests the presence of 14 chorotypes grouped in five major range types. Our results underline the role of Indochina as a key area for amphibian diversity and conservation. Among 423 species of Indochinese amphibians, 152 species (35.9%) were considered as data deficient (DD) or were not evaluated (NE) according to the IUCN Red List criteria; while 76 species (18.0%) were considered vulnerable (VU), endangered (EN) or critically endangered (CR), 20 species (4.7%) were considered to be near threatened (NT), and 175 species (41.4%) to be of the least concern (LC). Our study thus has implications for further conservation efforts on regional and global levels, as well as for understanding the biogeographic patterns of amphibian richness and endemism in Asia.
Aim The diversity of brood size across animal species exceeds the diversity of most other life‐history traits. In some environments, reproductive success increases with brood size, whereas in others it increases with smaller broods. The dominant hypothesis explaining such diversity predicts that selection on brood size varies along climatic gradients, creating latitudinal fecundity patterns. Another hypothesis predicts that diversity in fecundity arises among species adapted to different microhabitats within assemblages. A more recent hypothesis concerned with the consequences of these evolutionary processes in the era of anthropogenic environmental change predicts that low‐fecundity species might fail to recover from demographic collapses caused by rapid environmental alterations, making them more susceptible to extinctions. These hypotheses have been addressed predominantly in endotherms and only rarely in other taxa. Here, we address all three hypotheses in amphibians globally. Location Global. Time period Present. Major taxa studied Class Amphibia. Methods Using a dataset spanning 2,045 species from all three amphibian orders, we adopt multiple phylogenetic approaches to investigate the association between brood size and climatic, ecological and phenotypic predictors, and according to species conservation status. Results Brood size increases with latitude. This tendency is much stronger in frogs, where temperature seasonality is the dominant driver, whereas salamander fecundity increases towards regions with more constant rainfall. These relationships vary across continents but confirm seasonality as the key driver of fecundity. Ecologically, nesting sites predict brood size in frogs, but not in salamanders. Finally, we show that extinction risk increases consistently with decreasing fecundity across amphibians, whereas body size is a “by‐product” correlate of extinction, given its relationship with fecundity. Main conclusions Climatic seasonality and microhabitats are primary drivers of fecundity evolution. Our finding that low fecundity increases extinction risk reinforces the need to refocus extinction hypotheses based on a suggested role for body size.
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This paper is devoted to a review of the specific taxonomy of the frog genus Philautus Gistel, 1848. From 1822 to 1999, 177 nominal species were either described as members of this genus, or of other genera but subsequently referred to this genus. We tried to review the available information on the taxonomic status of these 177 names and the status of their name-bearing types. As a result of this review, 143 types are known to be extant, including 19 lectotypes and 8 neotypes designated and/or described in the present paper. In conclusion of this preliminary analysis, we provisionally distribute these 177 names in 84 valid species names in the genus Philautus, 37 invalid synonyms of the latter names, and 56 nominal species now referred to other genera. These results are highly provisional, both at specific and supra- specific levels. Additional works, using various characters and methods, will be necessary to confirm or reject the validity of a number of these species, and many additional species clearly remain to be discovered and described in the whole range of this genus. At supraspecific level, the taxonomy we use (a single genus Philautus with three subgenera) is also highly provisional, as the generic taxonomy of the whole subfamily Rhacophorinae is in strong need of revision. The present work will provide clear nomenclatural bases for future works on the phylogeny and taxonomy of this difficult group.
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The accretion of the Indian subcontinent to Eurasia triggered a massive faunal and floral exchange, with Gondwanan taxa entering into Asia and vice versa. The traditional view on the Indian-Asian collision assumes contact of the continental plates during the Early Eocene. Many biogeographic studies rely on this assumption. However, the exact mode and timing of this geological event is still under debate. Here we address, based on an extensive phylogenetic analysis of rhacophorid tree frogs, if there was already a Paleogene biogeographic link between Southeast Asia and India; in which direction faunal exchange occurred between India and Eurasia within the Rhacophoridae; and if the timing of the faunal exchange correlates with one of the recently suggested geological models. Rhacophorid tree frogs showed an early dispersal from India to Asia between 46 and 57 Ma, as reconstructed from the fossil record. During the Middle Eocene, however, faunal exchange ceased, followed by increase of rhacophorid dispersal events between Asia and the Indian subcontinent during the Oligocene that continued until the Middle Miocene. This corroborates recent geological models that argue for a much later final collision between the continental plates. We predict that the Oligocene faunal exchange between the Indian subcontinent and Asia, as shown here for rhacophorid frogs, also applies for other nonvolant organisms with an Indian-Asian distribution, and suggest that previous studies that deal with this faunal interchange should be carefully reinvestigated.
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Kuraishi, N., Matsui, M., Hamidy, A., Belabut, D. M., Ahmad, N., Panha, S., Sudin, A., Yong, H. S., Jiang, J.-P., Ota, H., Thong, H. T. & Nishikawa, K. (2012). Phylogenetic and taxonomic relationships of the Polypedates leucomystax complex (Amphibia). —Zoologica Scripta, 42, 54–70. We investigated the phylogenetic and taxonomic relationships and estimated the history of species diversification and biogeography in the Asian rhacophorid genus Polypedates, focusing on the Polypedates leucomystax complex, whose members are notoriously difficult to classify. We first estimated phylogenetic relationships within the complex using 2005-bp sequences of the mitochondrial 12S rRNA, tRNAval and 16S rRNA genes with maximum parsimony, maximum likelihood (ML) and Bayesian methods of inference. Polypedates exhibits well-supported monophyly, with distinct clades for P. otilophus, P. colletti, P. maculatus and the P. leucomystax complex, consisting of P. macrotis, and the Malay (Polypedates sp. from Malay Peninsula), North China (P. braueri), South China (Polypedates cf. mutus 1), Indochina (P. megacephalus), Sunda (P. leucomystax) and Laos (Polypedates cf. mutus 2) clades. In a subsequent phylogenetic analysis of 4696-bp sequences of the nuclear brain-derived neurotrophic factor (BDNF), sodium/calcium exchanger 1 (NCX), POMC, Rag-1, Rhod and Tyr genes using Bayesian methods of inference, all of these clades were recovered. Some clades of the P. leucomystax complex occur sympatrically and show high genetic diversity or morphological and acoustic differences. Similar tendencies were observed between some allopatric clades. Therefore, we consider each of these groups to be distinct specifically. We also estimated absolute divergence times within the genus using Bayesian methods. Divergence in Polypedates began with the divergence of a primarily South Asian Clade from the common ancestor of secondarily South-East Asia P. maculatus and South-East Asian members. The divergence between the latter occurred much later. The P. leucomystax complex diverged in the Pliocene, much later than other congeners, and seems to have been greatly affected by human-related dispersal after the Pleistocene.
A small rhacophorid frog from southern Vietnam is placed in the genus Kurixalus through molecular phylogenetic analysis. Because it is divergent genetically and morphologically from all known congeners, we describe it as a distinct species, K. viridescens. The species differs from the other congeners by an immaculate green dorsum, which is usually maculated gray to brown in the other species. With the addition of this new species, Vietnam now encompasses seven species of Kurixalus, and can be regarded as the center of speciation of this genus.
The ubiquitous Mexican and Central American stream frogs allied to Eleutherodactylus rugulosus form a confusing spectrum of distinctive to subtly different populations. The condition of the male secondary sexual features: presence or absence of vocal slits and presence or absence of nuptial pads on the thumb, combined with the geographically consistent color (white, pale yellow, gold, orange, red or chestnut) of the venter of adults in life, provide the key to untangling the species problem in this group. For purposes of analysis the populations were grouped by the male secondary sexual features and compared in detail on the basis of 15 other characters of morphology and coloration. Twelve species are recognized within the rugulosus group, and may be placed in four series based on the presence (+) or absence (-) of vocal slits and nuptial pads in adult males. ++: Eleutherodactylus milesi of northern Honduras; E. merendonensis of northwestern Honduras; E. punctariolus of southern Costa Rica and western Panama; E. fleischmanni of Costa Rica; and E. escoces (sp. nov.) a bright red-bellied new species from the slopes (1100-2100 m) of Volcan Barba, Volcan Irazu and Volcan Turrialba of Costa Rica; +-: E. vocalis of northwestern Mexico; a new species, E. azueroensis (sp. nov.) from the Peninsula Azuero of western Panama; and E. taurus of the Golfo Dulce lowlands of southwestern Costa Rica and adjacent Panama; -+: E. matudai from the Pacific slopes of extreme southern Mexico and adjacent Guatemala; and a new species, E. angelicus, from the Cordillera de Tilaran and Volcan Poas in Costa Rica; --: E. brocchi of Alta and Baja Verapaz, Guatemala; and the wideranging lowland and slope species known from Mexico to western Panama, E. rugulosus. The Atlantic versant Mexican populations of this species are distinctive and have been variously recognized as a subspecies of E. rugulosus or as a separate species by previous authors. The earliest name for this population is Hylodes berkenbuschii Peters and E. natator Taylor and E. vulcani Shannon and Werler are strict synonyms. The seemingly allpatrically isolated southern populations of E. rugulosus in eastern and southwestern Nicaragua, Costa Rica and Panama are slightly distinct from the main population system of E. rugulosus. The earliest name for the southern stock is Lithodytes ranoides Cope with Liohyla pittieri Günther a strict synonym. Neither of these populations is recognized as separate from E. rugulosus. E. chiquito Lynch placed by its describer in the rugulosus group is a synonym of E. greggi of extreme southern Pacific slope Mexico and Guatemala, which is a member of the distantly related mexicanus group. Members of the rugulosus group fall into four geographic and ecologic distribution patterns: a) lowland and slope species, centered on the distribution of the wide-ranging E. rugulosus population system, with the allopatric E. vocalis on the northwest Mexican periphery, E. azueroensis on the southwest Panama periphery, the small population of E. merendonensis in northwestern Honduras and E. taurus occupying the Golfo Dulce lowlands of Costa Rica and western Panama, where E. rugulosus occurs only along the Pacific slope (600-1200 m) of the Talamanca-Chiriqui massif; b) E. brocchi and E. matudai in the highlands of southern Mexico and Guatemala; c) E. milesi in the uplands of northern Honduras; and d) E. angelicus, E. escoces, E. fleischmanni and E. punctariolus in the mountains of Costa Rica and western Panama. Verified cases of sympatry are known for E. rugulosus with E. matudai, with E. punctariolus and E. fleischmanni and E. punctariolus. An analysis of relationships and evolutionary trends indicates that the rugulosus group consists of four subgroups: the E. rugulosus subgroup in which males lack nuptial pads (E. azueroensis, E. taurus and E. vocalis, with vocal slits and E. brocchi and E. rugulosus, without vocal slits); the E. fleischmanni subgroup (E. angelicus, E. escoces, E. fleischmanni and E. punctariolus); the monotypic E. merendonensis subgroup; and the E. milesi subgroup (E. matudai and E. milesi). The latter three subgroups have nuptial pads in males. Within these lines vocal slits have been lost secondarily in E. matudai and E. angelicus. Of living forms E. vocalis most resembles the presumed ancestral stock of the group, that must have had a wide lowland range in Miocene. Evolution within the E. rugulosus subgroup involved fragmentation, modification and replacement in the lowlands during the remainder of Cenozoic, with E. brocchi evolving at a fairly late date in the Guatemala highland. Two other stocks seem to have diverged from the ancestral lineage by evolving nuptial pads in adult males, among other features: one in northern Central America to give rise to the specialized isolated E. merendonensis and the tuberculate highland E. milesi subgroup; a second in the mountains of Costa Rica and Panama to evolve into the E. fleischmanni group. Convergent evolution is found in each stock toward a highly specialized stream adapted form with increased webbing (E. merendonensis, E. punctariolus and E. taurus) and large toe disks in the former two, as modifications for life on boulders amid torrential racing water and splashing waterfalls. Three independent invasions of the uplands of Central America by members of the group, the E. milesi subgroup in northern Central America, the E. fleischmanni subgroup in Costa Rica and Panama and E. brocchi in Guatemala are responsible in large part for the species diversity within the rugulosus group.
A morphometric and electrophoretic survey was conducted to examine taxonomic relationships among eight population samples of the Rana narina complex from the Ryukyu Archipelago of Japan and Taiwan. Five discrete morphotypes are differentiated, and these showed considerable genetic differentiation from each other. From the available information, each of the five morphotypes is judged to represent a species, and three are described as new. Rana utsunomiyaorum sp. nov. and R. supranarina sp. nov. are sympatric in Ishigakijima and Iriomotejima islands of the Yaeyama Group, and differ from the other members by having a shorter hindlimb. Rana utsunomiyaorum is the smallest in the complex, while R. supranarina is the largest. Rana amamiensis sp. nov. occurs on Amamioshima and Tokunoshima islands of the Amami Group and, like R. narina from Okinawajima of the Okinawa Group, has a long hindlimb; it differs from the latter species by having a larger body and relatively small tympanum. These two species differ from R. swinhoana from Taiwan by having a narrower disk on the third finger. A key to known species of the complex is given. Further, syslematics of the R. narina complex within Rana, body size in the two sympatric species, and sexual dimorphism found in this complex are discussed.
We construct the phylogeny of the Kurixalus odontotarsus species group using two mitochondrial (12S rRNA and 16S rRNA) genes in an attempt to delimit species boundaries within the Chinese K. odontotarsus group. With strong support values, three major clades are obtained, and all phylogenetic analyses reject monophyly of K. odontotarsus. The Tibetan lineage of K. odontotarsus was clustered with Kurixalus verrucosus from Myanmar (labeled Clade I); K. odontotarsus haplotypes from the type locality and nearby regions formed a distinct clade (labeled Clade II), and K. odontotarsus haplotypes from other places, together with those from Kurixalus bisacculus, K. verrucosus from Vietnam, and Kurixalus hainanus, formed a distinct clade (labeled Clade III). Clade II is the sister taxon to Clade III. The average uncorrected p-distance of 16S rRNA sequences between these three major clades range from 3.11% to 7.88%, which is obviously higher than that within these three major clades (0.03-1.89%). We propose that K. odontotarsus, K. bisacculus, and K. verrucosus should be treated as three independent species. The Tibetan lineage of K. odontotarsus does not belong to K. odontotarsus, and we tentatively place it in K. verrucosus. Kurixalus hainanus is considered a synonym of K. bisacculus. The distribution range of K. bisacculus should be expanded widely to include most regions of South China, and in China the distribution of K. odontotarsus should be limited to its type locality and nearby regions.
The phylogenetic relationships among 12 genera of treefrogs (Family, Rhacophoridae), were investigated based on a large sequence data set, including five nuclear (brain-derived neurotrophic factor, proopiomelanocortin, recombination activating gene 1, tyrosinase, rhodopsin) and three mitochondrial (partial 12S and 16S ribosomal RNA and the complete valine t-RNA) genes. Phylogenetic analysis of the nuclear gene sequences resolved three major clades. The first group included Philautus, Pseudophilautus, Kurixalus, Gracixalus, and Theloderma moloch; Pseudophilautus and Kurixalus were sister taxa. The second group consisted of Nyctixalus and Theloderma. The third group contained Feihyla, Polypedates, Rhacophorus, and Chiromantis vittatus; Polypedates and Feihyla were sister taxa. Analyses of the nuclear and mitochondrial genes supported the following results: (1) Genus Liuixalus formed the sister group of all other rhacophorines. (2) Philautus, Theloderma, and Chiromantis were not resolved as monophyletic genera. Four groups, including Philautus ocellatus and P. hainanus, P. longchuanensis and P. gryllus, P. banaensis, and P. quyeti nested well within the genera Liuixalus, Pseudophilautus, Kurixalus, and Gracixalus, respectively. (3) Theloderma moloch and Chiromantis vittatus did not cluster with other species of Theloderma and Chiromantis, respectively. Foam nesting evolved only once, as did laying eggs in a jelly-like matrix containing some bubbles. Terrestrial direct development evolved twice in the Rhacophoridae.