Wildlife, conservation, salamander

1. The salamandrid
genus
Tylototrito
n
Anderso
n,
187
1
(Colloquially known as Crocodile newts) represents an
ancient
salamanderlineage which earlier included 39
recognized
species globally (Frost, 2023).
Genus is subdivided into 2 subgenera: Tylototriton
Anderson, 1871 & Yaotriton Dubois & Raffaëlli, 2009.
Tylototriton species are known to distributed in
Sikkim, Darjeeling area in north-central India, &
Nepal east & southeast to central China, non-
peninsular Myanmar, non- peninsular Thailand, through
Laos to the central & northern highlands of Vietnam,
southern China, & Hainan Island (Frost, 2024).
INTRODUCTI
ON

2. Earlier, all the Tylototriton sp. in India & its adjacent
countries were assigned to Tylototriton verrucosus.
 Khatiwada et. al. (2015) described Tylototriton
himalayanus
from Nepal. Later reported from Darjeeling & western
Bhutan,
900-2,679 m elevation.
Thus, in the latest reviews on
distribution of Tylototriton salamanders
(Hernandez 2016; Hernandez et al.
2018).
 Indian populations were all
tentatively assigned to T. himalayanus
(Khatiwada et al. 2015).
 It was confirmed that T. verrucosus
were distributed in NE Myanmar,
adjacent western Yunnan, China, &
Chiang Rai & Chiang Mai Provinces, T.
T.
himalayanus

3. Back then none were
aware that this was
going to be a new
species?

4. Geographic
coordinate
s
& altitude
were
obtained using a
Garmin
GPSMA
P
receiver
60CS
x
(Garmi
n
GP
S
Ltd.
,
USA) & recorded in
datum WGS 84).
Microhabitat of salamander at the
Zaimeng Lake at 2212 m on 18 July 2022
~ 700 m ahead to
the Zaimeng Lake

5. External
morphology
 Crocodile newts were
described recently, based on a
combination of morphological
& molecular
investigations
Pomchot
e
et al.
(2020, 2021); Poyarkov et al.
(2021); Dufresnes&
Hernandez (2022);
Phung et al. (2023).
 Specimens of Tylototriton
sp. were photographed in life &
after preservation & then
checked by minor
dissection
s. Measurements were taken
using a digital caliper

6. RESUL
TS
The detailed morphometric data for
the Manipur population of
Tylototriton sp. by a different
coloration pattern; black
background pattern with bright orange-
red markings on parotoids, vertebral
ridge, rib nodules, vent, chest, light
mid-ventral line, whole limbs & tail;
& is geographically isolated from
north-eastern India.
T. zaimeng larvae T. zaimeng adult

7. MOLECULAR PHYLOGENETIC
ANALYSIS
The population of T. zaimeng
from Manipur, India, belongs to
*clade 1 (Fig.) where it is
reconstructed as a member of a
clade also including T.
panwaensis from Myanmar & T.
houi from Yunnan, China.
Although monophyly of this clade
had strong node support (98/1.0),
*genealogical relationships
amongst the 3 included lineages
appear to be insufficiently
resolved, with T. houi & T.
panwaensis forming a clade
which had strong support in BI-
analysis, but was poorly supported
in ML-analysis (76/1.0).
*Clade:
ancestor
.
Evolutionary descendants of
common
*Genealogy: Line of descent traced
continuously from ancestor.

8. SEQUENCE
ANALYSIS
Sequences of partial fragments of
ND2 & 16S rRNA mtDNA for 53
Salamandridae specimens, including
51 representatives of Tylototriton
(representing 39 taxa) & 2 sequences
of outgroup members of
Salamandridae Echinotriton
raffaellii Hernandez & Dufresnes
2022 & E. chinhaiensis (Chang
1932) were included in the final
alignment with a total length of up to
1665 bp.

9. GENETIC
DISTANCE
The interspecific uncorrected genetic p-distances between the sequences of ND2
mtDNA gene of Tylototriton sp. from Manipur, India & other members of T. verrucosus
species group varied from 3.0% (between T. zaimeng & T. panwaensis) to 8.6%
(between T. zaimeng & T. uyenoi) (Table 2). This study revealed significant
morphological differentiation between T. zaimeng sp. nov. & its sister species T.
panwaensis, which are clearly separated in the morphospace of PCA analysis (Fig.)

10. COMPARISON OF VOMERINE TOOTH
BETWEEN
Tylototriton zaimeng and Tylototriton
panwaensis
The peculiar curved bell-shape (Fig. 4A) of the *vomerine tooth series
observed in Manipur populations of crocodile newts was never previously
reported in any other member of Tylototriton species; therefore, this feature
appears to be an important diagnostic character supporting the full
species status of T. zaimeng sp. nov.
*Vomerine tooth: A small projections at mouth roof helpful in holding the prey.

11. DISCUSSION &
SUMMARY
 Many taxonomic issues
regarding Indian Tylototriton
remain unresolved & awaiting
further research.
 The discovery of T. zaimeng
brings the total species
number under the genus
Tylototriton to 40.
 It is endemic to the Zaimeng
Lake, Kangpokpi district,
Manipur.
 The study suggests that T.
verrucosus sensu stricto likely
does not occur in India. Thus,
range extant is likely restricted
to north-eastern Myanmar, south-
western Yunnan Province of
China and northernmost Thailand.

12. Fig. Distribution of Tylototriton ssp. in India & adjacent areas: 1 T. himalaynus; 2-6 T.
zaimeng; 7 undescribed Tylototriton sp.; 8 T. kachinorum; 9-10 T. panwaensis; 11-12 T.
panwaensis; 13 T. houi; 14- T. ngarsuensis; 15-17 T. shanorum.

13.  The recognition of Manipur populations
of Tylototriton as a distinct species
would benefit its conservation.
 This work emphasizes importance of
the integrative taxonomic approach,
combining data such as
molecular & morphological
differentiation for assessing the diversity
& evolutionary relationships.
 Mountain forests in north-eastern India
are threatened to a greater degree than
in other parts of India & hence,
immediate efforts to document the
biodiversity of the region are imperative
to ensure its conservation.
 Further underline the importance of
the montane subtropical forests of
north-eastern India as one of the key
center of herpetofaunal diversity in Asia.
At present, T. zaimeng is the
first & only new