Journal of Threatened Taxa |
www.threatenedtaxa.org | 26 June 2021 | 13(7): 18792–18799
ISSN 0974-7907 (Online) | ISSN 0974-7893
(Print)
https://doi.org/10.11609/jott.7195.13.7.18792-18799
#7195 | Received 15 February 2021 | Final
received 30 March 2021 | Finally accepted 01 May 2021 2019
Underestimated diversity of Cnemaspis Strauch, 1887 (Sauria:
Gekkonidae) on karst landscapes in Sarawak, East
Malaysia, Borneo
Izneil Nashriq
1 & Indraneil
Das 2
1,2 Institute of Biodiversity and
Environmental Conservation, Universiti Malaysia
Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia.
1 izneilnshrq@gmail.com, 2 idas@unimas.my
(corresponding author)
Editor: Raju Vyas,
Vadodara, Gujarat, India. Date of
publication: 26 June 2021 (online & print)
Citation: Nashriq,
I. & I. Das (2021).
Underestimated diversity of Cnemaspis Strauch,
1887 (Sauria: Gekkonidae)
on karst landscapes in Sarawak, East Malaysia, Borneo. Journal of Threatened Taxa 13(7): 18792–18799. https://doi.org/10.11609/jott.7195.13.7.18792-18799
Copyright: © Nashriq
& Das 2021. Creative Commons Attribution
4.0 International License. JoTT allows unrestricted use, reproduction, and
distribution of this article in any medium by providing adequate credit to the
author(s) and the source of publication.
Funding: This research was supported
by the Niche Research Grant
Scheme of the Ministry of Higher Education, Government of
Malaysia: NRGS/1087/2013(01); additional funding came from
the Sarawak Oil Palm Berhad: IA010200-0706-0015.
Competing interests: The authors
declare no competing interests.
Author details: Izneil Nashriq holds an MSc in Animal
Systematics from the Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak. His fields of interest
include taxonomy, ecology and
biogeography. Since 2016, he have been a member of the Herpetofaunal
Biology Lab, assisting with project involving herpetofaunal
conservation. Indraneil Das has a DPhil in Animal Ecology from the University of
Oxford, and was a Fulbright Fellow at the Museum of Comparative Zoology,
Harvard University. He is currently Professor at the Institute of Biodiversity
and Environmental Conservation, Universiti Malaysia
Sarawak, where he pursues his research and teaching interests in ecology,
systematics and conservation biology.
Author contributions: ID conceived, designed and
obtained funding. ID and IN collected field data and wrote the manuscript.
Acknowledgements: We thank the Sarawak Forest
Department for the issuance of collecting permits necessary for this study
(147)JHS/NCCD/600-7/2/107/Jld.2 and Park Permit N0.74/2019). The staff of the
Sarawak Forestry Corporation allowed entrance to the national parks and other
protected areas. We thank the Institute
of Biodiversity and Environmental Conservation, Universiti
Malaysia Sarawak, for supporting fieldwork and for lab assistance. We are grateful to Hayden Davis and his team
at the Bauer lab, Villanova University for field assistance and Alan Resetar and Joshua Matta of the Field Museum Natural
History, Chicago, for permission to reproduce the image of the holotype of Cnemaspis dringi.
Aaron Bauer and Pui Yong Min provided comments on an
earlier draft. This research was
supported by the Niche Research Grant Scheme of the Ministry of Higher
Education, Government of Malaysia: NRGS/1087/2013(01); additional funding came
from the Sarawak Oil Palm Berhad: IA010200-0706-0015.
Abstract: The paraphyletic group of Old
World rock gecko genus Cnemaspis, currently
comprises ~180 described species from Africa and Asia. The south-east Asian clade with 63 described
species, is most diverse on the Thai-Malay Peninsula, with just five species
known from Borneo, an island biodiversity hotspot. Karst regions are known as centres for species endemism, and vast areas of caves and
karst exist across northern Borneo.
Fieldwork from 2017 to 2020 recovered additional undescribed species of Cnemaspis from areas of karst forests in western and
northern Sarawak. These discoveries
emphasize the importance of preserving areas of limestone karst within
rainforest areas for maintaining species diversity, as well as accelerating
research on documenting the biota.
Keywords: Biodiversity, rock gecko,
systematics.
Bahasa Malaysia: Kumpulan paraphyletic cicak batu genus Cnemaspis dari Dunia Lama,
kini dianggarkan mempunyai ~180 spesis dikenal pasti dari
Afrika dan Asia. Klad Asia tenggara dengan 63 spesis terhurai, dilihat lebih pelbagai
di semenanjung Thai-Malay, dengan
hanya lima spesis dikenal pasti dari
Borneo, sebuah pulau kaya dengan kepelbagaian hidupan. Kawasan batu kapur diketahui sebagai kawasan tumpuan spesis endemik, dengan jumlah bilangan kawasan gua dan
batu kapur yang besar di utara Borneo. Kerja lapangan daripada 2017 hingga 2020 telah menambahkan bilangan spesis Cnemaspis dari kawasan hutan batu
kapur di barat dan utara Sarawak. Penemuan ini menekankan
kepentingan memelihara kawasan batu kapur
dalam hutan hujan tropika untuk
menjaga kepelbagaian spesis, serta meningkatkan
kajian dan dokumentasi biota.
Introduction
Sarawak State of East Malaysia,
located on the northwestern region of the island Borneo, can be divided into
two mineralization zones, corresponding to geological provinces, namely, West
Sarawak that hosts important metalliferous mineral deposits, which geologically
forms part of the Sunda Shield; and central-northern
Sarawak, which is renowned for fossil fuels, such as oil, gas and coal
deposits. Limestone outcrops cover 520km2
(or 0.4%) of Sarawak, and are reported to be shallow marine deposits ranging
from Upper Carboniferous to Miocene (Gendang et al. 2008). Older limestone deposits are located in
western Sarawak, while the younger one are found in central and northern
Sarawak. Karstic regions have been
regarded as biodiversity reservoirs that can be used as stock for repopulating
degraded environments during ecosystem reassembly (Schilthuizen
2004). Past research conducted on karst
formations and adjacent limestone forests in the Sundas
have resulted in improved knowledge of endemic species of flora and
invertebrates, as well as better appreciation of their endemicity. Microendemic
karst-dwelling species of squamate reptiles too have been identified and
described from such landscapes (Ellis & Pauwels 2012; Grismer
et al. 2015).
In Borneo, recent discoveries of lizard species have
been made, especially in areas with forest cover, including species of Cnemaspis (Grismer &
Chan 2009; Kurita et al. 2017), Cyrtodactylus
(Hayden et al. 2019), and Lygosoma (Karin et
al. 2018), highlighting the underestimated nature of the diversity. At the same time, the landscape of Borneo is
experiencing rapid change through deforestation from activities such as large-
to small-scale agriculture and colonization, unsustainable logging, fires,
mining and construction of infrastructure (Bennet 2017), resulting in the
degradation of the ecosystem. Cnemaspis Strauch, 1887 is a lizard genus allocated
to the family Gekkonidae, comprising ~180 described
species from tropical Africa and Asia (Uetz et al.
2021), making it one of the most speciose Old World gekkonid genera. As currently constituted, the genus has been
shown to be polyphyletic (Gamble et al. 2012; Grismer
et al. 2014). Members of the genus in
Asia occupy habitats ranging from lowland dipterocarp forests to primary and
old-growth forests, often within karst, granite or sandstone landscapes (Das
& Bauer 1998; Iskandar et al. 2017).
The south-east Asian Cnemaspis group has been reported from areas of Myanmar,
Thailand, Vietnam, Cambodia, Laos, Peninsular Malaysia, Singapore, Sumatra,
Borneo, and Java, in addition to numerous small and mid-sized islands off some
of these landmasses. With its
distribution extending from the subtropical eastern Himalaya and Indo-China, to
tropical areas of Sundaland, the highest diversity is
encountered on the Thai-Malay Peninsula (Kurita et al. 2017). Phylogenetic analyses of south-east Asian Cnemaspis have revealed two divergent lineages: the
southern Vietnamese insular endemics and a lineage containing three major
clades referred to as the Pattani, northern Sunda, and southern Sunda clades
distributed sporadically along the northern, western and southern edges of the Sunda Shelf, extending from southern Vietnam, Cambodia and
Thailand, southward through the Thai-Malay Peninsula, to Borneo (Grismer et al. 2014, 2015; Kurita et al. 2017; Wood et al.
2017). The Pattani clade, restricted to the
southernmost portion of peninsular Thailand, is sister to the northern Sunda and southern Sunda sister
clades. The northern Sunda
clade extends from Vietnam to central Peninsular Malaysia, while the southern Sunda clade extends from southern Peninsular Malaysia and
Singapore, eastward through the Seribuat, Anambas, and Natuna archipelagos
to northwestern Borneo.
The first member of the genus Cnemaspis on Borneo was reported by Gray (1845),
described as Heteronata kendallii,
based on two specimens presented to the British Museum of Natural History by
Captain Edward Belcher, with locality given simply as “Borneo”. Smith (1925) described the second Bornean
species, Gonatodes nigridius,
from “Mt. Gading” (= Gunung
Gading). Dring (1979) subsequently discovered that one of Gray’s
syntypes was a juvenile Cnemaspis nigridia (Smith, 1925), and designated the other as the
lectotype of Cnemaspis kendallii. Das & Bauer (1998) described Cnemaspis dringi
from Labang Camp, Bintulu, Sarawak and Grismer & Chan (2009) recorded the first karst-endemic
species on Borneo, Cnemaspis paripari from Gua Pari Pari (Fairy Cave) and Gua Angin (Wind Cave), in the Bau region of Sarawak.
The most recent discovery was by Kurita et al. (2017), who described Cnemaspis leucura
from Gunung Penrissen,
Sarawak. These five species currently
represent the known diversity of the genus on Borneo. Bornean Cnemaspis
are represented by two major lineages (the nigridia
group and the kendallii group); however,
Kurita et al. (2017) recovered a basal polytomy of Cnemaspis
dringi, the nigridia
group, and the kendallii group, suggesting
multiple origins of the Bornean Cnemaspis.
During recent fieldwork, we
discovered additional populations of Cnemaspis
in areas of limestone formations which, on the basis of morphological
characters and phylogenetic divergence, we regard as new species. We here describe the distribution and
habitats of these geckos.
Materials
and Method
Inventories were conducted between
2017 and 2020, and collections were made during both day and night at a number
of localities in Sarawak. A hand-held
Global Positioning System Garmin, GPSMap 76CS
receiver (datum WGS 84) was used for georeferencing. We used Google Maps and Google Earth Pro to
identify areas for sampling, prioritizing the presence of intact vegetation
with a greater possibility of the occurrence of members of the genus. Sites inspected included national parks,
nature reserves and other areas within karst formations, as well as non-karst
areas. The visual encounter survey
method was used to locate individuals, and macro- and micro-habitat features
were identified. Specimens were
photographed using a Nikon D600 DSLR camera and 105mm Micro-Nikkor
f/2.8 D lens, illuminated by a speedlight flash unit
(SB800), using a Lastolyte softbox. Temperature and humidity of the study sites
were recorded using CENTER 315 humidity temperature meter. Specimens were collected manually, euthanized
with the use of sodium pentobarbital, fixed in 10% buffered formalin prior to
storage in 70% ethanol in the collection of the museum of the Institute of
Biodiversity and Environmental Conservation, Universiti
Malaysia Sarawak (UNIMAS). Tissue
samples were taken and preserved in 95% ethanol for DNA analysis.
Study sites
We obtained research permit for
collection and permission to enter national parks and conduct studies from the
Sarawak Forest Department for multiple localities. Habitat associations of members of the
lineage and habitat assessments were conducted by day, while collections of
specimens were conducted between 2000–2300 h.
A total of 27 areas were surveyed during the present study (Table 1),
including primary and secondary forests.
Sites included the Kayan Plateau sandstone of
Bako National Park; Kayan sandstone of Gunung Gading National Park, the Serapi Range, Kubah National
Park, Santubong National Park, and on the Pedawan Formation of Gunung Penrissen. The Bau Limestone which includes karst towers and formations,
such as Fairy Cave and Wind Cave Nature Reserve, and Dered
Krian National Park; Kedadom
and Pedawan limestone formations in Siburan and Serian District,
consisting of multiple karst hills and caves, such as Gua
Raya, Gua Rabus, Gua Silabur, Gua
Simadang and Gua Sireh; the Belaga Formation of
central Sarawak, Pelagus National Park; the Nyalau/Sibuti Formation of Niah National Park; and also the Melinau
Limestone and Mulu Formation of the Gunung Mulu National Park,
northern Sarawak.
Limestone hills are
characteristically steep-sided, with subvertical to
overhanging cliffs. The base of
limestone hills exhibit deep horizontal notches or undercuts due to dissolution
by streams, groundwater or swamp water, and the collapse of the limestone
cliffs contributing to the reduction in size of limestone hills. Mazed with numerous
caverns and cave systems, limestone hills range in height and size, and provide
multiple microclimates.
Results
In western Sarawak, habitats
occupied by Cnemaspis are present both within
the protected areas network (such as national parks) and in unprotected
ones. Additional populations were
recorded within the Siburan and Serian
districts. The deposits of Kedadom and Pedawan formations
are of Late Jurassic ----– Late Cretaceous age.
The karst towers of these regions reach elevation of approximately 700m,
and are dominated by mesophytic flora. Streams, often originate from these
formations. Some of the karstic areas
are bounded by human activities such as orchards and plantations, limestone
mining and land development. Individuals
were found usually on ground level spatially constrained to an area with
multiple degree of surfaces. In northern
Sarawak, the habitat of Cnemaspis is located
within the Melinau Limestone formation, within the
protected boundaries of Gunung Mulu
National Park. Deposited in the Eocene
to the Miocene, this geological formation reaches a height of approximately
1,700m. Specimens were found at ground
level, on stalactites and on walls of the cave entrance.
Substrate identified associated
with Cnemaspis can be classified into granite,
limestone, sandstone and vegetation. Cnemaspis kendallii
is here considered the most generalized species, being observed on multiple
substrates, and showing overlapping distribution (= syntopic)
with C. nigridia, C. paripari,
and C. leucura. C. kendallii
may persist in disturbed areas such as the detached forest patch of Sama Jaya Nature Reserve, which serves as a rainforest park
in an urban setting. Covering 38ha, the
population is disconnected from the major forest region. Another example of persistency is observed in
the population of C. paripari from the Fairy
Cave Nature Reserve which occurs as an isolated karst hill measuring about 4ha,
detached from the major Bau Limestone formation by
800 m of lowland. Members of the genus are often found syntopic
with other gecko species, especially Bent toed geckos, Cyrtodactylus.
Rock crevices act as shelters
into which geckos typically retreat when threatened. Furthermore, crevices also serve as a nursery
for eggs. Egg-clutches were observed in
pairs, embedded within depressions of mineral formations in such moisture-laden
microhabitats. For the first two
species, communal nesting, as evidenced from multiple egg-scars on rocks, was
noticed. Habitat descriptions of Bornean
Cnemaspis are summarised
in Table 2.
Discussion
The discovery of undescribed Cnemaspis reveals the poorly-known nature of the
herpetofauna of Borneo. Based on surveys
and satellite imagery, sites of occurrence tend to be isolated and restricted
to mineral formations and intact secondary to primary forests. Although environmental conversion can occur
naturally, human activities have intensified the decline of many habitats. Major conservation concerns that can be
identified from this study are major and minor agricultural practices, mining
of limestone for industry and deforestation.
These factors seriously influence the quality and extant of Cnemaspis habitats in Sarawak.
Populations of Cnemaspis geckos are fragmented by human
intervention. The hills of the Bau Limestone stretching to the Pedawan
formation and along with Kedadom and Sadong formations comprise karst outcrops of which some
parts are mined for industrial uses such as cement production. Shifting agriculture and mining activities
are both widespread and sometimes intense in Sarawak, which, if not mitigated
or done sustainably, not only affect these geckos, but in a wider context,
result in loss of biological diversity as a whole.
Conclusion
The accretion of species of Cnemaspis on Borneo has been somewhat sluggish,
starting with C. kendallii in 1845, C.
nigridia in 1925, C. dringi in 1998, C. paripari
in 2009, and most recently, C. leucura
in 2017. The effort of locating
specimens may be thwarted by their occupancy of relatively inaccessible areas
and microhabitats, besides the ecologically cryptic nature of these
species. In addition to the described
species, four from western Sarawak, and one in central Sarawak, morphological
and genetical data reveal the existence of three additional species from
western and northern Sarawak. Mineral
formations of Sarawak are home to a disproportionate number of Cnemaspis, all except one showing rupicolous adaptations.
Only C. kendallii inhabits
forested areas, and is sylvicolous. On the other hand, C. nigridia is restricted to granite formations; C.
paripari endemic to limestone formations; and C.
leucura from sandstone formations. All three undescribed species reported in
this study inhabit separate limestone formations. This brings the number of species to a total
of eight occurring on the island of Borneo, an increase of 60% of the fauna.
The study was focused largely in
western Sarawak. The formations in
western Sarawak are relatively more accessible compared to those of central and
northern Sarawak. Future efforts should
be directed in finding species of Cnemaspis in
these latter areas, especially along regions of limestone karst.
Table 1. Study sites in Sarawak
State, East Malaysia (Borneo), with reference to geological formations and
general habitat descriptions. Asterix indicates locality where species of Cnemaspis have been recorded.
|
|
Localities, Division |
Coordinates |
Geological Formation and
General Habitat Type |
|
1* |
Bako National Park,
Kuching |
1.7179°N, 110.446°E |
Plateau Sandstone
Formation ~ 200m. Coastal forest, swamp forest,
mixed dipterocarp forest |
|
2* |
Bengoh Range, Bau |
1.252°N, 110.102°E |
Kayan Sandstone
Formation ~ 900m. Mixed dipterocarp forest, with
agriculture and human settlements on foothills |
|
3* |
Borneo Highlands at
Gunung Penrissen, Padawan |
1.135°N, 110.221°E |
Kayan Sandstone
Formation ~ 1,000m. Mixed dipterocarp forest, submontane forest |
|
4* |
Dered Krian National Park, Bau |
1.3802°N, 110.163°E |
Bau Limestone
Formation ~ 400m. Karst formation, dominated by
herbaceous plants and mid-sized trees; conversion to commercial plantation on
foothills |
|
5* |
Gua Angin, Bau |
1.416°N, 110.133°E |
Bau Limestone
Formation ~ 50m. Cave systems, dominated by
herbaceous plants and mid-sized trees |
|
6* |
Gua Pari Pari, Bau |
1.381°N, 110.117°E |
Bau Limestone
Formation ~ 250m. Cave systems, dominated by
herbaceous plants and mid-sized trees |
|
7* |
Gua Rabus, Temurang, Padawan |
1.207°N, 110.273°E |
Pedawan Formation ~ 500m. Cave system dominated by
herbaceous plants and mid-sized tree; natural vegetation hemmed by
horticulture |
|
8 |
Gua Raya, Kampung Chupak, Serian |
1.285°N, 110.429°E |
Sadong Formation ~ 600m. Abandoned bird-nest harvesting
operations in cave system, broken plank walks, dominated by herbaceous plants
and mid-sized trees |
|
9* |
Gua Silabur, Lobang Batu, Tebakang, Serian |
0.969°N, 110.516°E |
Sadong Formation ~ 50m. Cave system dominated by
herbaceous plants to mid-sized trees and bounded by local horticulture. |
|
10* |
Gua Simadang, Temurang, Padawan |
1.207°N, 110.274°E |
Pedawan Formation ~ 500m. Cave system dominated by
herbaceous plants to mid-sized trees and bounded by local horticulture. |
|
11* |
Gua Sireh, Kampung Bantang, Serian |
1.180°N, 110.463°E |
Sadong Formation ~ 350m. Archaeological site. Cave
system dominated by herbaceous plants and mid-sized trees, hemmed in by
horticulture |
|
12* |
Gunung Gading National Park, Lundu |
1.691°N, 109.845°E |
Gading Formation ~ 850m. Mixed dipterocarp forest, with
granite boulders and scree at foothills |
|
13* |
Kampung Mambong, Siburan |
1.355°N, 110.351°E |
Bau Limestone
Formation ~ 100m. Weathered limestone hills,
dominated by herbaceous plants and mid-sized trees, hemmed in by horticulture |
|
14* |
Kampung Puak, Bau |
1.358°N, 110.141°E |
Bau Limestone
Formation ~ 400m. South of Dered
Krian and Fairy Cave, its sharp limestone ridges
dominated by herbaceous vegetation and mid-sized trees; small stream present |
|
15* |
Kampung Skio, Bau |
1.396°N, 110.176°E |
Bau Limestone
Formation ~ 250m. Outcrops connected to Dered Krian formation; cave
opening with small stream |
|
16* |
Kubah National Park,
Kuching |
1.612°N, 110.196°E |
Kayan Sandstone
Formation ~ 850m. Mixed dipterocarp forest;
forest stream originate from upper elevation |
|
17* |
Lambir Hills National
Park, Miri |
4.198°N, 114.042°E |
Lambir Formation ~ 450m. Mixed dipterocarp forest, with
steep slope |
|
18* |
Limestone Hills of Jambusan-Samadang, Siburan |
1.319°N, 110.255°E |
Pedawan Formation ~ 300m. Karst formation, bounded by
river and oil palm plantation |
|
19* |
Limestone hills, Serian-Tebedu, Serian |
1.130°N, 110.444°E |
Kedadom Formation ~ 300m. Karst formation, dominated by
herbaceous vegetation; presence of small stream |
|
20* |
Gunung Mulu National Park, Miri |
4.041°N, 114.812°E |
Melinau Limestone
Formation ~ 1,750 m; Mulu Formation ~2,376m. Massive karst formation, submetamorphic slates and hard sandstones, mixed
dipterocarp forests at points of sampling; other vegetation types at higher
elevations or other sites within the National Park |
|
21 |
Nanga Pelagus, Belaga |
2.169°N, 113.056°E |
Pelagus Formation Low sandstone hills; small
forest streams |
|
22 |
Niah National Park,
Miri |
3.824°N, 113.761°E |
Subis Limestone ~ 350m. Karst formation within lowland
mixed dipeterocarp forest |
|
23 |
Pelagus National Park, Belaga |
2.188°N, 113.056°E |
Pelagus Formation Mixed dipterocarp forest at
edge of Rajang River |
|
24* |
Ranchan Pool Forest, Serian |
1.143°N, 110.584°E |
Sadong Formation ~ 800m. Sandstone hill with forest
stream, frequented as recreational area |
|
25* |
Sama Jaya Nature
Reserve, Kuching |
1.522°N, 110.387°E |
Alluvium flat ~ 0m. Forest reserve within city of
Kuching, comprising Kerangas (Bornean heath)
forests with blackwaters and mixed dipterocarp forest |
|
26* |
Gunung Santubong National Park, Kuching |
1.743°N, 110.317°E |
Kayan Sandstone
Formation ~ 800m. Mixed dipterocarp forest, with
streams and waterfalls |
|
27 |
Tinbarap Oil Palm
Plantation, Miri |
4.055°N, 114.238°E |
High Value
Conservation forest ~ 0m. Conserved forest patch;
blackwater swamp forest |
Table 2. Summary of Cnemaspis habitat use and activity on Borneo.
|
Species |
Active period |
Preferred substrate |
|||
|
Granite |
Limestone |
Sandstone |
Vegetation |
||
|
kendallii |
Diurnal |
+ |
+ |
+ |
+ |
|
nigridia |
Nocturnal |
+ |
- |
- |
- |
|
dringi |
NA |
NA |
NA |
NA |
+ |
|
paripari |
Nocturnal |
- |
+ |
- |
- |
|
leucura |
Nocturnal |
- |
- |
- |
- |
|
Species 1 |
Nocturnal |
- |
+ |
- |
- |
|
Species 2 |
Nocturnal |
- |
+ |
- |
- |
|
Species 3 |
Nocturnal |
- |
+ |
- |
- |
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