Underestimated species diversity within the Rhacophorus rhodopus and Rhacophorus bipunctatus complexes (Anura, Rhacophoridae), with a description of a new species from Hainan, ChinaAuthorTang, Shangjinghttps://orcid.org/0009-0006-0706-421XKey Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin 541004, ChinaAuthorXiao, FanrongGuangxi Key Laboratory of Rare and Endangered Animal Ecology, College of Life Science, Guangxi Normal University, Guilin 541004, ChinaAuthorLiu, Shuo0000-0001-7825-3006Ministry of Education Key Laboratory for Ecology of Tropical Islands & Key Laboratory of Tropical Animal and Plant Ecology of Hainan Province, College of Life Sciences, Hainan Normal University, Haikou 571158, ChinaAuthorWang, LijunGuangxi Key Laboratory of Rare and Endangered Animal Ecology, College of Life Science, Guangxi Normal University, Guilin 541004, ChinaAuthorYu, GuohuaKey Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin 541004, ChinaAuthorDu, Lina0000-0002-2246-643XKey Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, Guilin 541004, ChinatextZoosystematics and Evolution20242024-05-211002625643journal article10.3897/zse.100.118879675CD047-159E-4363-A0A6-ECD9549A989BRhacophorus qiongicasp. nov.Figs 6
,
7
,
8
,
9Rhacophorus rhodopus
—
Fei 1999
;
Fei et al. 2004
,
2009
,
2010
,
2012
;
Shi 2011
;
Nguyen et al. 2014
.
Rhacophorus bipunctatus
—
Orlov et al. 2002
.
Type material.Holotype
.
GXNUYU 000691
, adult
male
, collected on
14 July 2023
by
Lingyun Du
from
Diaoluo Mt.
,
Lingshui
,
Hainan
,
China
(
18 ° 43 ' 28 " N
,
109 ° 52 ' 12 " E
, ca
914 m
a. s. l.
).
Paratypes
.
GXNUYU
000690, an adult male, collected at the same time as the
holotype
from the type locality by Lingyun Du and Jiaqi Luo;
GXNU
HN 110501 ‒ HN 110503,
three adult
males, collected on
20 July 2021
by Fanrong Xiao from the type locality; and
three adult
males (
GXNUYU
000693,
GXNUYU
000696,
GXNUYU
000697) and an adult female (
GXNUYU
000698) collected on
11 July 2023
by Qiumei Mo and Chunyi Pang from Yinggeling,
Hainan
,
China
(
19 ° 2 ' 24 " N
,
109 ° 34 ' 12 " E
, ca
670 m
a. s. l.).
Etymology.
The specific name
qiongica
is derived from Qiong (琼), referring to
Hainan
,
China
, and meaning good and beautiful in Chinese. The specific name means that this species is very beautiful, and in
China
, it is distributed in
Hainan
. We suggest the English common name “
Hainan
flying frog ” and the Chinese common name “ 琼树蛙 (Qióng Shù Wā) ”.
Diagnosis.
The new species is assigned to
Rhacophorus
by the presence of intercalary cartilage between terminal and penultimate phalanges of digits, terminal phalanges of fingers and toes Y-shaped, the tip of the digits expanded into disks with circummarginal grooves, fingers webbed, tarsal projections present, dermal folds along the forearm and tarsus present, and a horizontal pupil (
Jiang et al. 2019
).
Rhacophorus qiongicasp. nov.
differs from its congeners by a combination of the following characters: 1) medium body size (adult males
SVL35.1‒38.2 mm
); 2) dorsal surface red brown; 3) entire web between fingers and toes; 4) webbing between toes purely scarlet; 5) small black blotches on flank; 6) bands on limbs distinct; 7) throat smooth; 8) absence of dermal appendage on snout tip; 9) absence of small black spots on head sides; 10) palm smooth without small tubercles; and 11) tibiotarsal articulation reaching beyond eye.
Description of
holotype
.
Adult male, body size medium (
SVL37.8 mm
); head width (
HW13.2 mm
) longer than head length (
HL
12.0 mm); snout blunt pointed, sloping in profile, protruding beyond the margin of lower jaw in ventral view; snout length (
SL5.5 mm
) longer than diameter of eye (
ED4.4 mm
); canthus rostralis distinct, curved; loreal region oblique, concave; nostril oval, lateral, slightly protuberant, slightly closer to tip of snout than to eye; internarial space (
IND3.8 mm
slightly smaller than interorbital distance (
IOD4.2 mm
), nearly equal to the width of the upper eyelid (
UEW3.6 mm
); pupil horizontal; pineal ocellus absent; tympanum distinct (
TD2.3 mm
), rounded, about half eye diameter (
ED4.4 mm
); supratympanic fold narrow, flat; tongue cordiform, attached anteriorly, notably notched posteriorly; choanae oval; vomerine teeth present in two series, touching the inner front edges of the choanae; an internal single subgular vocal sac; a vocal sac opening on the floor of the mouth at each corner.
Forelimbs thin, length of forearm and hand (
FHL18.2 mm
) is about half snout-vent length; relative length of fingers I <II <IV <III; tips of all fingers expand into discs with circummarginal and transverse ventral grooves, disc of finger I smaller than discs of other fingers; entire web between fingers, webbing formula: I 2‒2 II 1 ‒ 1.5 III 1 ‒ 1 IV; subarticular tubercles rounded and prominent, formula 1, 1, 2, 2, proximal one smaller than distal one on the third and fourth fingers; supernumerary tubercles below the base of finger absent; metacarpal tubercle single, inner, oval and prominent (Fig.
7
).
Hindlimbs slender and long, heels overlapping when legs at right angle to body, tibiotarsal articulation reaching beyond eye; tibia length (
TL18.6 mm
) nearly equal to length of forearm and hand (
FHL18.2 mm
), longer than foot length (
FL16.7 mm
), and shorter than length of tarsus and foot (
TFL25.6 mm
); relative length of toes I <II <III <
V
<IV; tips of all toes expanded into discs with circummarginal and transverse ventral grooves; entire web between toes, webbing formula I 1‒1 II 1 ‒ 1 III 1 ‒ 1 IV 1 ‒ 1
V
; subarticular tubercles rounded and prominent, formula 1, 1, 2, 3, 2; supernumerary tubercles absent; single inner metatarsal tubercle, oval (Fig.
7
).
Dorsal skin smooth with very fine granules; throat and ventral surface of forelimbs smooth; chest, belly, and ventral surface of thighs granular (Figs
6
,
7
); dermal folds on forearm, tarsus, heels, and vent present.
Lateral, dorsal, and ventral views of the holotype of
R. qiongicasp. nov.
(
GXNU
YU 000691) in life.
Dorsal, ventral, and lateral views of the holotype of
R. qiongicasp. nov.
(
a ‒ c
) in preservative and ventral views of its hand (
d
) and foot (
e
).
Coloration in life.Iris light brown; dorsal surface red brown, mottled with two discontinued rows of dark patches and scattered with small black spots on dorsum; dark brown bands and small black spots on dorsal surface of limbs; upper part of flank orange red and lower part of flank orange yellow, scattered with a few small black blotches; skin of ventral surface semi-transparent, mottled with orange yellow on throat and belly; ventral, anterior, and posterior surfaces of limbs orange yellow; discs of fingers and dorsal surface of fingers I ‒ III orange yellow; discs of toes and toes I ‒ IV red; web between fingers yellow, mottled with red; web between toes completely red.
Color of
holotype
in preservative.
The color faded, but the pattern remained the same as in life. Dorsal surface brown, with dark patches and spots; dorsal side of limbs barred with dark brown; throat, chest, belly, webbing, ventral surface of limbs, and anterior and posterior parts of thighs faded to yellowish; a few small black blotches on flank.Sexual dimorphism.The body size of males is smaller than that of female; adult males have an internal single subgular vocal sac with a pair of slit-like openings on the floor of the mouth at each corner. Additionally, adult males have a milk-white nuptial pad on the inner side of the base of finger I.Morphological variation.
The number of small black spots on the flank varied among specimens. The
holotypeGXNUYU
000691 and
two paratypes
(
GXNUYU
000698 and
GXNU
HN 110502) have multiple small black spots on flank;
paratypesGXNUYU
000690 and
GXNUYU
000697 have no black spots on flank; and
paratypesGXNUYU
000693 and
GXNUYU
000696 have two small black spots on flank (Fig.
8
). Additionally, dorsal color pattern also varied among specimens, as the
two paratypesGXNUYU
000696 and
GXNUYU
000698 have yellowish-brown blotches on dorsal surfaces of the body and limbs (Fig.
9
).
Variation of black spots on flank among paratypes of
R. qiongicasp. nov.
from Hainan, China.
Dorsal view of paratypes
GXNU
YU 000696 (
a
) and
GXNU
YU 000698 (
b
) in life.
Distribution and ecology.
The species is distributed in
Hainan
,
China
and
Gia Lai
,
Vietnam
. In Hainan, the species was found usually in shrubs and small arbors at elevations ranging from
600 to 850 m
(
Shi 2011
; as
R. rhodopus
) and called from 19: 00 to 03: 00 every night during the breeding season (from May to July), with a peak at about 22: 00 (
Sun et al. 2017
; as
R. rhodopus
). The
types
in this study were found in roadside bushes ca.
1‒2 m
above the ground (Fig.
10
). There were temporary puddles under the bushes, and there is a lake (Tianchi) and a stream nearby the road in the
type
locality.
Chirixalus doriaeBoulenger, 1893
,
Kurixalus hainanus
(
Zhao, Wang & Shi, 2005
)
, and
Polypedates megacephalusHallowell, 1861
were also found in sympatry at the
type
locality.
Habitat of
R. qiongicasp. nov.
at the type locality.
Comparisons.
Currently, there are three known species in the
R. rhodopus
and
R. bipunctatus
complexes, namely
R. bipunctatus
,
R. napoensis
, and
R. rhodopus
. The new species differs from
R. bipunctatus
by smaller body size (male
SVL35.1‒38.2 mm
, n = 8 vs.
37.8‒50.4 mm
, n = 28; Table
7
), dorsal surface red brown (vs. green; Fig.
11
), spots on flanks small (vs. large; Fig.
11 b
), bands on limbs distinct (vs. indistinct), and throat smooth (vs. granular;
Bordoloi et al. 2007
); from
R. napoensis
by smaller body size (male
SVL35.1‒38.2 mm
[37.1 ± 1.3, n = 8] vs.
39.7‒44.2 mm
[41.3 ± 1.8, n = 5]), snout pointed without dermal appendage on tip (vs. snout pointed with a dermal appendage on tip; Fig.
11
), black spots on flanks small (vs. large; Fig.
11
), and throat smooth (vs. granular; Fig.
11
); and from
R. rhodopus
(Clade C) by black spots on axillar and flanks small (vs. usually large), absence of small black spots on head sides (vs. present; Fig.
12
), palm smooth without small tubercles (vs. palm rough with rows of small tubercles; Fig.
12
), smaller tympanum, wider upper eyelid, larger distance between nostril and eye (Table
4
), and tibiotarsal articulation reaching beyond eye (vs. tibiotarsal articulation reaching eye).
Morphological comparison between the new species and members of
Rhacophorus rhodopus
and
R. bipunctatus
complexes. Characters are: ① dorsal color: 0 = brown, 1 = green; ② black spots on flank: 0 = small, 1 = large; ③ bands on limbs: 0 = distinct, 1 = indistinct; ④ throat: 0 = smooth, 1 = granular; ⑤ snout: 0 = pointed without appendage on tip, 1 = pointed with appendage on tip; ⑥ black spots on head side: 0 = absent, 1 = present; ⑦ palm: 0 = smooth without tubercles, 1 = rough with tubercles; ⑧ tibiotarsal articulation: 0 = reaching beyond eye, 1 = reaching eye. “? ” means unknown.
Species
Male
SVL
①
②
③
④
⑤
⑥
⑦
⑧
R. qiongicasp. nov.
35.1–38.2 (37.1 ± 1.3, n = 8)
0
0
0
0
0
0
0
0
R. rhodopus
33.1–38.7 (35.3 ± 2.3, n = 6)
0
1
0
0
0
1
1
1
R. bipunctatus
37.8–50.4 (n = 28)
1
1
1
1
0
?
0
0
R. napoensis
39.7–44.2 (41.3 ± 1.8, n = 5)
0
1
0
1
1
1
1
0
Dorsal (
a.
BMNH 1872.4. 17.127, lectophoront from Khasi Hills, India) and lateral (
b.
CAS 229893, collected from Putao, Kachin State, Myanmar) views of
R. bipunctatus
, throat (
c
) and lateral view (
d
) of
R. napoensis
(
GXNU
YU 000170), and throat (
e
) and lateral view (
f
) of
R. qiongicasp. nov.
(
GXNU
YU 000693). The images of
a
and
b
were reproduced from
Bordoloi et al. (2007)
and
Wilkinson et al. (2005)
, respectively.
Head side and ventral surface of the hand of
R. rhodopus
(
a, b.GXNU
YU 090186) and
R. qiongicasp. nov.
(
c, d.GXNU
YU 000693).
Both the present and previous phylogenetic analyses revealed that
R. norhayatiae
,
R. reinwardtii
,
R. kio
,
R. borneensis
, and
R. helenae
are imbedded in the
R. rhodopus
and
R. bipunctatus
complexes. The new species can be easily distinguished from these five species by the dorsal surface being red brown (vs. green) and the web between toes being red with no black pigmentation (vs. black pigmentation present).