It‘s all in the name: Another new Cyrtodactylus Gray (Squamata: Gekkonidae) from northern Mizoram, North-east India
Author
Lalremsanga, Hmar Tlawmte
0000-0002-3080-8647
Developmental Biology and Herpetology Laboratory, Department of Zoology, Mizoram University, Aizawl 796004, Mizoram, India Govt. Champhai College, Champhai 796321, Mizoram, India & https: // orcid. org / 0000 - 0002 - 3080 - 8647
Author
Colney, Zosiamliana
0009-0009-4800-1807
https: // orcid. org / 0009 - 0009 - 4800 - 1807
Author
Vabeiryureilai, Mathipi
0000-0001-8708-3686
Developmental Biology and Herpetology Laboratory, Department of Zoology, Mizoram University, Aizawl 796004, Mizoram, India Govt. Champhai College, Champhai 796321, Mizoram, India & https: // orcid. org / 0000 - 0001 - 8708 - 3686
Author
Malsawmdawngliana, Fanai
0000-0002-3061-8325
Developmental Biology and Herpetology Laboratory, Department of Zoology, Mizoram University, Aizawl 796004, Mizoram, India Govt. Champhai College, Champhai 796321, Mizoram, India & https: // orcid. org / 0000 - 0002 - 3061 - 8325
Author
Bohra, Sanath Chandra
Author
Biakzuala, Lal
Author
Muansanga, Lal
Author
Das, Madhurima
0000-0002-6260-4227
Help Earth, 16, RNC Path, Lachitnagar, Guwahati 781007, Assam, India & Department of Zoology, Assam Don Bosco University, Sonapur 782402, Assam India & https: // orcid. org / 0000 - 0002 - 6260 - 4227
Author
Purkayastha, Jayaditya
Help Earth, 16, RNC Path, Lachitnagar, Guwahati 781007, Assam, India
text
Zootaxa
2023
2023-11-13
5369
4
553
575
https://www.mapress.com/zt/article/download/zootaxa.5369.4.5/52259
journal article
10.11646/zootaxa.5369.4.5
1175-5326
10150612
030933EB-07C2-48BE-9B7F-EEACFA102A50
Cyrtodactylus vairengtensis
sp. nov.
Figs. 3–7
;
Table 3
Holotype
:
Adult male
([
MZMU 2903
];
Fig. 3
), from the jointed weathered siltstone bed along a public link road (
24.501111°N
;
92.762222° E
;
elevation
230 m
a.s.l.
), in the backyard of UPC-NEI church building,
Hall Veng
,
Vairengte
,
Kolasib District
,
Mizoram
, north-east
India
collected on
5 June 2022
by
Zosiamliana Colney
and Joseph Vanlalhriata.
FIGURE 3.
A: Dorsal view, B: ventral view, C: details of dorsal pholidosis, D: dorsal view of head, E: ventral view of head and lateral view of head (F: Right and G: Left) of the holotype of
Cyrtodactylus vairengtensis
sp. nov.
(MZMU2903).
FIGURE 4.
Cyrtodactylus vairengtensis
sp. nov.
in life [A: holotype (2903); B: MZMU2626, C: Uncollected individual and D: MZMU2742)].
Paratypes
:
One adult
male (
MZMU2904
) and
one female
(
MZMU2905
), same collection details as
holotype
.
Two adult
males (
MZMU2901
,
MZMU2902
) collected from a rocky wall covered by vegetation along
Aitlang
road (
24.495556 °N
;
92.757500 °E
;
elevation
168 m
a.s.l.
),
Field Veng
,
Vairengte
,
Kolasib District
,
Mizoram
, north-east
India
on
5 June 2022
by
Zosiamliana Colney, H.
T
. Lalremsanga, Lal Muansanga and Joseph Vanlalhriata and
two adult
females (
MZMU2626
,
MZMU2742
) collected along a narrow public slope stone steps walkway (
24.501111 °N
;
92.762222°E
;
elevation
230 m
a.s.l.
),
Hall Veng
,
Vairengte
,
Kolasib District
,
Mizoram
, northeast
India
by
Zosiamliana Colney
,
C. Lalfamkima
,
Alfred Lalsanglura
and
Joseph Vanlalhriata
on 12 November 2021 and 2 April 2022.
FIGURE 5.
Type series of
Cyrtodactylus vairengtensis
sp. nov.
FIGURE 6.
Habitat shots of
Cyrtodactylus vairengtensis
sp. nov.
at Vairengte A: Roadside at Hall Veng, B: Stone steps at Hall Veng and C: Vegetated rocky wall at Field Veng.
Diagnosis:
Cyrtodactylus vairengtensis
sp. nov.
is a moderate-sized gecko (adult SVL
57.6–73.6 mm
) having 10–11 supralabials and 10–11 infralabials; 22–23 longitudinal rows of dorsal tubercles which are rounded and conical to feebly keeled; 34–39 continuous series of paravertebral tubercles between the level of axilla and groin; 35–41 mid-ventral scale rows across the ventral region; 9–11 precloacal pores in males; 5–9 precloacal pits (no pitted scales in
one specimen
) in females and 14–17 subdigital lamellae under toe IV; ventral surface of tail without transversely arranged enlarged subcaudal scales. Dorsum has dark brown blotches intermixed with bordering whitish patches that form an irregular body pattern; original tail has alternating dark brown and transverse whitish bands.
Description of
holotype
:
Holotype
in good preservation condition. Adult male, SVL
60.6 mm
. Head less than one-third of SVL (HL/SVL 0.30), longer than broad (HW/HL 0.55), somewhat depressed (HD/HW 0.68) and distinct from neck, snout less than half of the head length (SO/HL 0.36); scales on the canthus rostralis, snout and forehead are homogeneous, interorbital area flat, canthus rostralis broadly rounded; loreal region inflated with granular scales; scales on the interorbital and occipital regions somewhat homogeneous in size; scales on the interorbital region of the head to the nape are slightly smaller than those of the forehead, somewhat blunt and juxtaposed having no distinct tubercles; eye approximately one-quarter of the head length (OD/HL 0.23); vertical pupil with crenulate margins; supraciliaries moderate in size, blunt, somewhat oval, those present in the middle (above the orbit) are largest and most prominent; ear opening oval, obliquely orientated, small (EL/HL 0.077); orbit to ear distance is less than the eye diameter (OE/OD 0.93); rostral wider than long (RL/RW 0.57), partially and dorsally divided by a poorly developed rostral groove; single enlarged supranasal on either side, separated by five small granular internasals; rostral in contact with the first supralabial, nasals, two supranasals and five small internasals; nostrils semicircular, openings laterally orientated, posterior half covered by the nasal pad, each nasal is in broad contact with the rostral and surrounded by the supranasal, first supralabial, and four small postnasals; a single row of small granular scales separate the orbit from the supralabials; mental wider than long (ML/MW 0.53), triangular; two well developed postmentals on either side; the inner pair of postmentals more than one and a half of the size of the outer pair (PMIIL/PMIL 0.52), bordered by the mental, infralabial I, the outer postmental and five gular scales on either side; outer postmentals bordered by inner postmental, infralabials I and II, and four gular scales on either side; 11 supralabials on each side, bordered by a row of medium to large sized scales, somewhat flat and elongated; 11 infralabials on each side, a row of enlarged gular scales (largest anteriorly) ventrally bordering infralabials II to V; gular region with small granular scales throughout except for a few scale rows bordering the mental, postmentals and infralabials which are larger, flat and juxtaposed.
FIGURE 7.
The arrangement of precloacal pores in
Cyrtodactylus vairengtensis
sp. nov.
Body moderately slender, trunk length approximately half of the snout to vent length (TRL/SVL 0.47); dorsal scales are mostly heterogeneous, small rounded granule like scales intermixed with irregularly arranged, bluntly conical and feebly keeled enlarged tubercles (3–4 times the size of granular scales) becoming slightly smaller and more conical towards the flanks, the largest on the mid-dorsum; tubercles extending posteriorly from the occipital region to the second segment of the tail and are smaller on the nape than those of the dorsum; 23 mid-dorsal tubercle rows throughout the dorsum; 34 paravertebral tubercles between the level of the axilla and the level of the groin; ventrolateral folds are poorly developed, not denticulate but with a single row of continuous, projected smooth tubercles; ventral scales smooth, cycloid, imbricate to sub-imbricate and are in 40 rows, much larger than dorsals and are slightly smaller in size under thighs; ten distinct precloacal pores in a continuous series; a single row of six slightly enlarged scales (median scale being the largest) between the precloacal pores and the vent; four small postcloacal tubercles on both the sides of the tail base. Forearm (FL/SVL 0.16) and tibia (CL/SVL 0.18) short; digits narrow, without a scansorial pad, strongly inflected at each joint, all bearing robust, recurved claws; subdigital lamellae transversely widened beneath the basal phalanx; basal lamellae 4-5-6-5-5 on the right manus and 4-6-5-6-5 on the right pes; distal lamellae (intervening rows of non-lamellar granular scales between the basal and distal lamellae series in parentheses): 5(4)-7(2)-8(3)-8(3)-8(3) on the right manus, 5(4)-7(2)-10(2)-8(4)-10(3) on the right pes; interdigital webbing absent from both the manus and pes; relative length of digits: I <II <V<III<IV on the right manus, I <II <V<III<IV on the right pes; scales on the palms and soles are smooth, weakly raised, subimbricate; scales on the forelimbs are heterogeneous in size, comprising flat, imbricate to subimbricate scales on the upper arms, and those on forearms are heterogeneous in size, ventral portion covered with heterogenous sized imbricate scales; scales on the hindlimbs are heterogeneous in size, dorsal surfaces of the thighs and shanks have slightly enlarged scales, intermixed with scattered, enlarged, conical, feebly keeled tubercles; anterior portion of thighs and ventral aspect of hindlimbs have slightly enlarged, somewhat smooth, imbricate to subimbricate scales.
Tail complete, oval in cross-section, dorsoventrally depressed; dorsal tubercles on the tail base (tail portion containing the hemipenes) are enlarged, flat, and pointed; few enlarged, flat and distinctly keeled, tubercles randomly scattered near the first segment of the tail gradually decreasing slightly towards the second segment, remaining dorsal caudal scales smooth, flat, heterogenous in size and shape; subcaudal scales smooth, imbricate and heterogeneous in size, forming a mid-ventral series of granular scales; no enlarged transverse or paired row of subcaudals.
Colouration in life (
Fig. 4A
): Dorsum primarily greyish brown in colour; head somewhat brownish grey; forehead without markings; nape with a pair of discontinuous longitudinal markings, somewhat parallel to each other. A distinct, broad, dark-edged post ocular stripe with a lighter border runs from behind eyes to ear opening. Dark brown blotches with lighter edges distributed across dorsum, sometimes forming a reticulate pattern. Forelimb and hindlimb with indistinct whitish or cream-coloured blotches intermixed with dark brown blotches. Tail with alternating dark brown and transverse white bands. Venter off white.
Colouration in preservative
: The colour is pale in comparison to the live specimen and the dark spots on the dorsum have partially darkened.
Variation:
Refer to
Table 3
for meristic, morphometric and basic pholidosis variation within the
type
series of
C. vairengtensis
sp. nov.
(
Fig. 5
). The
type
series of
C. vairengtensis
sp. nov.
includes
three adult
males (MZMU2901, MZMU2902 and MZMU2904) having prominent pre-cloacal pores (9–11) and
three adult
female specimens (MZMU2905, MZMU2626, and MZMU2742), all having visible pitted scales (5–9) in their precloacal region except MZMU2742 have none.
Comparisons:
Here, we have compared
Cyrtodactylus vairengtensis
sp. nov.
with all described members of the
Cyrtodactylus khasiensis
clade, as well as with
C. kamengensis
of the
C. peguensis
clade including species (
C. cayuensis
,
C. martinstollii
,
C. markuscombaii
,
C. himalayicus
,
C. tamaiensis
) that are not assigned to any group/ clade due of the absence of molecular data.
We have differentiated
Cyrtodactylus vairengtensis
sp. nov.
from its congeners by a combination of the following characters: a smaller maximum adult size, SVL
73.6 mm
max. (
C. kazirangaensis
min. 80.0 mm;
C. montanus
min.
78.2 mm
;
C. arunachalensis
max
81.7 mm
;
C. khasiensis
max.
81.1 mm
;
C. martinstolli
max. 82.0 mm;
C. tamaiensis
max. 90.0 mm;
C. cayuensis
max.
79.8 mm
;
C. jaintiaensis
min.
96.2 mm
;
C. brevidactylus
max. 88.0 mm;
C. chrysopylos
max.
83.8 mm
;
C. aunglini
max.
81.6 mm
); presence of 9–11 distinct precloacal pores in males (
Fig. 7
)
versus
6 PcP in
C.ngopensis
, 12 PcP in
C.namtiram
, 3–5 PcP in
C. lungleiensis
, 5–7 PcP in
C. bengkhuaiai
, 7–8 PcP in
C. aaronbaueri
, 11–18 PcP in
C. agarwali
, 34–38 PcFP in
C. karsticola
, 40 PcFP in
C. tamaiensis
, 26–39 PcFP in
C. guwahatiensis
, 7 PcP in
C. markuscombaii
, 14 PcP in
C. septentrionalis
, 29–37 PcFP in
C. tripuraensis
, 12–13 PcP in
C. aunglini
, 0–8 PcP in
C. martinstolii
, 16–29 PcFP in
C. gansi
and 7 PcP in
C. siahaensis
; 5–9 precloacal pits (no pitted scales in
one specimen
) in females
versus
no visible pitted scales in females of
C. bengkhuai
, 0–3 pitted scales in
C. siahaensis
and 10–13 (no pitted scales in
1 specimen
) precloacal pits in
C. bapme
; 22–23 rows of feebly keeled, conical dorsal tubercles throughout the dorsum
versus
19–20 rows in
C. ngopensis
, 24–26 rows in
C. arunachalensis
, 21 rows in
C. namtiram
, 18 rows in
C. cayuensis
and
C. mandalayensis
, 14–15 rows in
C.markuscombaii
, 16–18 rows in
C. nagalandensis
, 16–20 rows in
C. chrysopylos
, 21 rows in
C. tamaiensis
, 24–28 rows in
C.lungleiensis
, 23–27 rows in
C. mombergi
, 27–30 rows in
C. brevidactylus
, 19–20 rows in
C. jaintiaensis
, 19-21 rows in
C. tripuraensis
and 21 rows in
C. himalayicus
; presence of 34–39 rows of paravertebral tubercles between the level of axilla and groin separates it from
C. exercitus
(32–34 rows)
C. jaintiaensis
(30–34 rows) and
C. septentrionalis
(38–42 rows); 35–41 rows of mid ventral scales across the venter (32 rows in
C. mandalayensis
; 30–34 rows in
C. kamengensis
and
C. urbanus
, 30–35 rows in
C. guwahatiensis
; 57 rows in
C. myaleiktaung
; 34- 35 rows in
C. nagalandensis
; 33 or 34 rows in
C. himalayicus
and 47–49 rows in
C. aunglini
); 14–17 subdigital lamellae beneath fourth toe (
versus
9–13 subdigital lamellae in
C. kamengensis
,
18–19 in
C. brevidactylus
,
19–23 in
C. aunglini
and
C. chrysopylos
;
13 in
C. martinstolli
;
18 in
C. myaleiktaung
,
19 in
C. markuscombaii
;
19–22 in
C. khasiensis
and
C. mombergi
;
10 in
C. himalayicus
and
C. gansi
).
A single row of 5–6 slightly enlarged scales below the pored scales (median scale being the largest) distinguishes
Cyrtodactylus vairengtensis
sp. nov.
from
C. arunachalensis
, which has three to four rows of slightly enlarged scales below the pored scales. Moreover, the presence of indistinct dark dorsal spots in the dorsum differentiates
Cyrtodactylus vairengtensis
sp. nov.
from
C. bapme
(7-9 paired dark blotches),
C. urbanus
(6–8 paired dark brown blotches in the dorsum),
C. agarwali
(8–9 pairs of dark blotches in the dorsum),
C. aaronbaueri
(11–12 prominent blotches in the dorsum),
C. ayeyarwadyensis
(9–11 paired dark blotches in the dorsum) and
C. tripuraensis
(presence of dark brown blotches in the dorsum usually bordered posteriorly by white punctuations in the latter two species), as well as from
C. khasiensis
,
C. martinstolii
and
C.cayuensis
by the presence of uniform granular subcaudals (
versus
presence of a median series of paired enlarged subcaudals in the latter three species).
In
Cyrtodactyus vairengtensis
sp. nov.
, the dorsal tubercles reach at least the second segment of the tail, which differentiates it from
C. kazirangaensis
as well as from
C. montanus
(tubercles not extending beyond first tail segment and tubercles reaching at least till the third tail segment respectively in the latter two species).
We performed statistical analyses based on the meristic values (
Table 3
) to compare the new specimens with respect to the recently described ‘Mountain clade’ species from
Mizoram state
(
C. ngopensis
,
C. aaronbaueri
,
C. bengkhuaiai
,
C. lungleiensis
,
C. siahaensis
) along with certain members of the ‘Lowland clade’ from
Meghalaya state
(
C. agarwali
,
C. karsticola
,
C. exercitus
). In males, one-way ANOVA with taxon as a factor showed significant differences in the PcP/PcFP (
F
8
,
22
= 113.56,
p
<0.001), IL (right) (
F
8,22
= 3.41,
p
= 0.011); FILamc (
F
8,22
= 3.52,
p
= 0.009), FIILamb (
F
8,22
= 2.44,
p
= 0.047), FIIILamc (
F
8,22
= 5.12,
p
= 0.001), TILamc (
F
8,22
= 3.16,
p
= 0.016), TIIILamb (
F
8,22
= 2.76,
p
= 0.028), and TIVLamb (F
8,22
= 2.42, p = 0.048); and through the alternative Kruskal-Wallis H test, significant differences are also seen in the FIVLamc [
H
(8) = 21.59,
p
= 0.006], TILama [
H
(8) = 17.09,
p
= 0.029], TIILamc [
H
(8) = 20.47,
p
= 0.009], and TIVLamc [H (8) = 15.67,
p
= 0.047]. In females, one-way ANOVA with taxon as a factor also showed significant differences in the pitted precloacal scales (
F
5,11
= 3.24, p
=
0.049), PVT (
F
5,11
= 3.60,
p =
0.036), DTR (
F
5,11
= 25.36,
p <
0.001), and TILamc (
F
5,11
= 8.70,
p
= 0.002). Excluding the sex-specific meristic characters (i.e. PcP/ PcFP in males and pitted precloacal scales in females), the interspecific different characters identified through univariate analyses among males (IL (right), FILamc, FIILamb, FIIILamc, FIVLamc, TILama, TILamc, TIILamc, TIIILamb, TIVLamb, and TIVLamc) and females (PVT, DTR, TILamc) were further adopted for determining the clustering of the species through multivariate analysis (PCA) by pooling sexes (
Fig. 8
). Given that the correlation matrix showed weak correlations between the variables (r <0.75), we utilized all the selected variables for the PCA. A total of five components were extracted (eigen values> 1) that accounted for 75% of the total variation, and the three components accounted for 59% of the total variation of the data, with PC1, PC2 and PC3 representing 32%, 15%, and 11% respectively. The representation of the first two components depicts the clustering of the new specimens and
C. aaronbaueri
with a marginal separation between them along the first and second principal components. Furthermore, ordination of the second and third components also depicts a marginal separation between the new specimens and
C. aaronbaueri
along the second principal components. Therefore, based on morphology and genetic assessment, we consider the new specimens from Vairengte as a new species of
Cyrtodactylus
.
Distribution and Natural History:
We have collected individuals of the new species only from Vairengte town, one of the townships in the Kolasib District, bordering the Cachar District (
Assam
) in the extreme northnortheast of
Mizoram
. The area lies with in an ecotonal region between the Lushai upland hills in
Mizoram
and the Cachar lowland plains in
Assam
. The approximate aerial distances from the type locality of the new species to the type locality of its closest sister species,
C. aaronbaueri
(
Purkayastha
et al.
2021
)
is ca.
78 km
towards the south, in the State capital, Aizawl. The species is found to be nocturnal and all the specimens of
C. vairengtensis
sp. nov.
were collected between ca. 2100-2240 h, from ca.
80 cm
to
260 cm
above ground. The
holotype
and
two paratypes
(MZMU2904 & MZMU2905) were on jointed weathered siltstone bed along a public link road (
Fig. 6A
), whilst other
paratypes
were collected from a rocky wall covered by vegetation along public light vehicle road (
Fig. 6B
) and stone steps (
Fig. 6C
). All the specimens were collected from anthropogenic areas fringed with secondary forest in the peripheral part of the town. Climatic conditions in the area varied between 15°C and 21°C during winters and 27°C to 34°C during summers; the annual average rainfall is
2,674.5 mm
(
Guhathakurta
et al.
2020
). The forest type of the location is tropical semievergreen forest as per the classification by
Singh
et al.
(2002)
, corresponding to the semievergreen 2B/C2 forest type (
Champion & Seth 1968
), and the vegetation around the area comprises mixed plantation trees such as
Areca catechu, Artocarpus
heterophyllus
and
Tectona grandis
.
Other common plants include
Amomum dealbatum, Ananas
comosus, Blumea lanceolaria, Manihot esculenta, Melocanna baccifera, Mikania micrantha, Musa paradisiaca, Mussaendra roxburghii
and
Thysanolaena maxima
.
Ferns such as
Adiantum pedatum
,
A. aleuticum, Athyrium
felix, Diplazium esculentum
and
Dryopteris filix
were also abundant.
Etymology.
The specific epithet is derived from the name of Vairengte town, Kolasib District of the state of
Mizoram
from where the
type
series were collected.
Suggested common name.
Vairengte bent-toed gecko