Lineage delimitation and description of nine new species of bush frogs (Anura: Raorchestes, Rhacophoridae) from the Western Ghats Escarpment
Author
Vijayakumar, S. P.
Author
Dinesh, K. P.
Author
Prabhu, Mrugank V.
Author
Shanker, Kartik
text
Zootaxa
2014
3893
4
451
488
journal article
10.11646/zootaxa.3893.4.1
2bf9de45-df17-4f15-b5be-31d9f26a9621
1175-5326
287578
1D415B70-A128-4605-9C60-BDF6E3FE7CF5
5.
Raorchestes emeraldi
sp. nov.
(
Figures 2
,
3
&
8
;
Tables 2
&
3
)
Holotype
:
ZSI/
WGRC
/V/A/873 (
CESF
1353), an adult male (SVL
36.5 mm
), collected by S.P. Vijayakumar and Saunak Pal in
August 2011
from a site (
10.3690 N
,
76.9948 E
) in a wet evergreen forest fragment, Valparai Plateau, Anaimalai Massif (
Fig 1
), Peninsular
India
.
FIGURE 8.
Raorchestes emeraldi
sp. nov.
(a) profile in life; (b) eye profile in life; (c) dorsal profile of holotype; (d) ventral profile in life.
Paratype
:
ZSI/
WGRC
/V/A/874 (
CESF
1365), an adult female (SVL
50.5 mm
), collected by S.P. Vijayakumar and Saunak Pal in
August 2011
from a site (
10.3919 N
,
76.9942 E
) in a wet evergreen forest fragment, Valparai Plateau, Anaimalai Massif (
Fig 1
), Peninsular
India
.
Lineage diagnosis.
Raorchestes emeraldi
sp. nov.
can be diagnosed by its affinity to the
Hassanensis
clade (
Fig 3
) and in having moderate levels (16S—3.5%) of divergence from its sister lineages
R. ponmudi
and
R. hassanensis
. Morphologically, it shows differences in the dorsum coloration (uniform green), groin patterns and iris coloration (
Fig 8
). Of the known species of
Raorchestes
, this species was found to be of the largest (
50.5 mm
: female). Phylogenetic position and morphological distinctness are the two axes on which this lineage is diagnosed.
Field diagnosis. Morphology.
Raorchestes emeraldi
sp. nov.
resembles its sister lineage
R. ponmudi
in overall morphometric characters, however it exhibits strong divergence in coloration from its sister lineages,
R. hassanensis
and
R. ponmudi
. It could be distinguished in having green dorsum (
Fig 8
a) (vs. dorsum with varying shades of brown in
R. ponmudi
(Biju and Bossuyt, 2009))
; region of groin, front and back of thighs, under side of tibia and front of metatarsal with brown and yellow reticulated pattern (vs. posterior surface of thighs light chocolate brown vermiculated with grey patches of variable size in
R. ponmudi
(
Biju and Bossuyt, 2009
)
; Additionally new species can be differentiated from other related congeners by the following combination of characters; (1) large adult size (SVL
36.5–50.5 mm
, n=2); (2) head width larger than head length (HW 15.2–21.0 mm & HL
12.9–16.2 mm
); (3) snout sub acuminate, sub equal to eye length (SL 5.0–
6.5 mm
& EL
5.1–6.9 mm
); (4) skin on dorsum lateral side smooth and ventral region granular; (5) dorsum green with minute yellow spots.
Geography.
Restricted to the Anaimalai Massif (see natural history and distribution for details).
Description of
holotype
(all measurements in mm). A large sized bush frog (SVL =
36.5 mm
), width of head broader than head length (HW =
15.2 mm
; HL =
12.9 mm
), flat dorsally; snout short and sub acuminate, slightly protruding beyond mouth. Snout length is sub equal to diameter of eye (SL = 5.0 mm, EL =
5.1 mm
). Canthus rostralis angular rounded, loreal region slightly concave. Interorbital space (IUE = 4.0 mm) flat and equal to upper eyelid (UEW =
3.3 mm
). Interorbital space between posterior margins of the eyes 1.9 times that of anterior margins (IFE = 7.0,
IBE
=
13.3 mm
). Nostrils oval and nearer to the tip of the snout. Moderate symphysial knob. Pupil horizontal. Tympanum moderate, rounded, visible behind the eye, 2.3 times less than the eye diameter (
TYD
=
2.2 mm
). Tongue bifid, granular with a papilla. Supratympanic fold from behind eye to shoulder.
Relative length of fingers I<II<IV<III, finger tips with well developed disks (fd3 =
2.7 mm
; fw3 =
1.4 mm
) with distinct circum-marginal grooves, fingers with dermal fringes on both sides. Webbing on palm absent, subarticular tubercles moderate, rounded and pre-pollex indistinct. Supernumerary tubercles absent.
Hind
limb long, heels touch when folded at right angles to the body. Thigh/Femur (TL = 17.0 mm), slightly lesser than Shank/Tibia (ShL =
18.2 mm
) length and foot (FOL = 16.0 mm) and much less than heel to tip of fourth toe (
TFOL
= 26.0 mm). Relative toe length I<II<III<V<IV, webbing medium, web formula (I 1-
1 II
½-
1 III
½-
1 IV
1- 0 V). Tibiotarsal articulation reaches posterior corner of eye. Outer metatarsal tubercle, supernumerary tubercles and tarsal tubercle absent.
Color in life.
Dorsum uniform green with scattered yellow spots (
Fig 8
a); green colouration extending to canthus, arm up to ¼th of outer finger (rest of the fingers flesh coloured, finely speckled with brown), surface of femur, tibia, tarsus and base of outer two toes. Armpits are fleshy, purplish with fine brown specks. Upper lip golden white, lower lip and throat region iridescent off white. Lateral part of mid belly with yellow spots on a dark brown background. Groin, anterior and posterior femur with distinct yellow blotches on a dark brown background. Outer posterior orbital ring bluish green, upper edge of iris dark maroon, interior of iris golden brown with fine markings radiating towards the outer edge. Outer edges of the iris with a green wash (
Fig 8
b).
Etymology.
The species is named after its dominant dorsum colour ‘emerald’.
Natural history and distribution.
We discovered this species from a rainforest fragment at the eastern edge of the Valparai plateau. It appears to be a forest species, occurring in the higher elevation (
1249–1488
, n = 7) wet evergreen forests of the Anaimalai Massif (
Fig 1
&
2
). It replaces
R. ponmudi
, a common species of the low and mid-elevations (mean ~
900 m
, n=77) of southern parts of the Western Ghats. We suspect a narrow zone of overlap between these species around
1200–1400 m
in the Valparai plateau.