On some additions to the amphibians of Gunung Inas Forest Reserve , Kedah , Peninsular Malaysia

A survey on amphibian fauna was conducted in compartments 15, 16, and 17 of Gunung Inas Forest Reserve (GIFR), Kedah, Peninsular Malaysia for a period of two-and-a-half years, starting from January 2016 to May 2018, with a total of 20 visits. Observations and collections of amphibian species were carried out in and along the rivers, forest streams, forest pools, rock pools, cascade areas, waterfalls, ditches, temporary pools, forest floors, and forest trails. In total, 41 species of amphibians, belonging to 25 genera, and seven families were collected over the survey period. Of these, 11 species were ranids, followed by 10 dicroglossids, seven rhacophorids, six microhylids, four bufonids, two megophryids, and a single ichthyophiids (Ichthyophis sp.). From these observations, it is being pointed out that 15 species of amphibians represent new records for GIFR, while two species were not detected. This increases the known amphibian diversity of Gunung Inas Forest Reserve from 28 to 41 species.


INTRODUCTION
Banjaran Bintang Hijau is the third largest mountain range in Peninsular Malaysia, and located on the west coast. Its structure, which include hills, slopes, peaks, plateaus, streams, and rivers influences the landscape of northern Peninsular Malaysia. This important mountain range extends approximately 140 km from Bukit Besar, Thailand to the central Malaysian state of Perak. The highest peak in this mountain range is Gunung Bintang (1,862 m), followed by Gunung Bintang Utara (1,835 m) and Gunung Inas (1,801 m), which is within the state of Kedah. The Gunung Inas Forest Reserve (GIFR) is part of Banjaran Bintang Hijau, and placed in the district of Baling, Kedah. This forest reserve is managed by the South Kedah Forest Department. This forest reserve covers 37,346 ha of lowland dipterocarp, hill dipterocarp, lower montane and upper montane forests (Kiew 1998;Manokaran 1998 Research on the amphibian fauna has been undertaken at various locations in Kedah. These include a study in Ulu Muda Forest Reserve (UMFR), which recorded 56 species of frogs (Norhayati et al. 2005); Gunung Jerai where 14 species were recorded (Ibrahim et al. 2006a); Langkawi Island where 16 and 24 species were recorded respectively (Grismer et al. 2006;Ibrahim et al. 2006b); Beris Valley where 14 species were recorded (Shahriza et al. 2011a); Lata Bukit Hijau where 18 species were recorded (Shahriza et al. 2011b); Gunung Inas Forest Reserve (GIFR) where 28 species were recorded (Ibrahim et al. 2012a); Bukit Perangin Forest Reserve (BPFR) where 15 species were documented (Ibrahim 2012b); Tupah Recreational Forest (TRF) where 13 species were documented (Shahriza et al. 2013a);and Ulu Paip Recreational Forest (UPRF) where 20 species were documented (Shahriza & Ibrahim 2014).
Previous studies on the amphibian diversity (Ibrahim et al. 2012a) and reptile diversity (Shahriza et al. 2013b) have been conducted in GIFR. Ibrahim et al. (2012a) reported 28 species of amphibians, belonging to 21 genera and six families. This included 10 species of ranids, eight dicroglossids, four bufonids, three rhacophorids, two megophryids, and one microhylid (Ibrahim et al. 2012a). This study was undertaken over a period of six months. In this study, we surveyed a larger area including compartments 15, 16, and 17 of GIFR and for a longer duration of 30 months, in the hope that additional amphibian species would be recorded with greater survey effort.
Specimens were collected at night, between 2000 and 2400 h, via active sampling or opportunistic encounters, by teams of three to five people. The amphibians were captured by hand or sweep nets. The specimens were kept in moist plastic bags and brought back to the laboratory for measurements and further inspections. In the laboratory, the snout-vent length (SVL) and head width (HW) of the captured specimens were measured using a digital calliper (LC= 0.1 mm). Voucher specimens were prepared by euthanizing the specimens with tricane. Specimens were fixed with 10% formalin, stored in 70% ethanol and deposited at the School of Pharmaceutical Sciences, Universiti Sains Malaysia (USM) for reference. Tissue samples (thigh muscles) of some selected species were collected, stored in 95% ethanol and deposited at the same location for further analysis. The specimens were photographed in situ or in the laboratory, using an Olympus digital camera, model SP800. Species identification was based on morphological characteristics, such as body shape, colour, pattern, webbing, fingers and toes following J TT Berry (1975), Ibrahim et al. (2008), and Grismer (2011)

RESULTS
Forty-one amphibian species, belonging to 25 genera and seven families were recorded from compartments 15, 16, and 17 GIFR. These included 11 ranids, 10 dicroglossids, seven rhacophorids, six microhylids, four bufonids, two megophryids, and a single ichthyophiid ( Table 1). Comparison of amphibian species recorded by Ibrahim et al. (2012a) and this study is presented in Table 2.

Species accounts Family Bufonidae Duttaphrynus melanostictus (Schneider, 1799)
16USM-GIFR-DM01 Adult male, SVL= 58 mm, HW= 27 mm An adult male was captured beside the road, along the way to Sungai Sedim Recreational Forest, in January 2016. The choruses of this species were recorded in November 2016 and October 2017, along the roadside ditches.

Rentapia flavomaculata Chan, Abraham & Badli-Sham, 2020
This tree toad was observed in September 2016 and October 2017, perched on the branches of a tree situated adjacent to the river (4-6 m above ground). In October 2017, seven adult males were detected, while actively calling from tree branches along the banks of Sungai Sedim.

Phrynoidis asper (Gravenhorst, 1829) (Image 2)
This river toad and its chorus were observed in every visit to GIFR. The toad was very common and often sighted perched on the wet granite rocks or bounders, hiding under big rocks or resting on the ground along the banks of Sungai Sedim, Sungai Reyau, and Sungai Teruna. Additionally, the toads were also encountered living along the small forest streams, forest floors, ditches, near the base camp and in the toilets. Sometimes they can be found resting on tree branches, 2 -3 m above the ground.

Family Dicroglossidae Fejervarya cancrivora (Gravenhorst, 1829)
An adult was sighted in June 2016 and October 2017. When first observed, it was found on the ground, at the edge of a temporary ditch, along the way to Sungai Sedim Recreational Forest.

Limnonectes blythii (Boulenger, 1920) (Image 3)
16USM-GIFR-LB01 Adult, SVL= 127 mm, HW= 48 mm This riparian species can be found along the banks of Sungai Sedim, Sungai Reyau and Sungai Teruna. It also can be encountered along the small forest streams, swampy areas and on the forest floors. In September 2016, an adult was captured, perched on tangled roots, on the banks of Sungai Teruna.

Limnonectes utara Matsui, Daicus & Norhayati, 2014 (Image 4)
17USM-GIFR-LU01 Adult, SVL= 68 mm, HW= 34 mm An adult was collected perched on the wet mossy rock, in a small forest stream (1-2 m width), which flows to Sungai Sedim in October 2017. The area was shaded and surrounded by lowland dipterocarp forest. This species, earlier known by the name L. kuhli, represents a new record for GIFR.

Limnonectes deinodon Dehling, 2014
17USM-GIFR-LD01 Adult, SVL= 38 mm, HW= 20 mm A single specimen was captured resting on a rotten log, on the banks of a small forest stream, along Sungai Reyau trail in July 2017.

Ingerophrynus parvus X X
Rentapia flavomaculata X X Phrynoidis asper X X

Rhacophorus nigropalmatus Boulenger, 1895 (Image 14)
17USM-GIFR-RN01 Adult, SVL= 93 mm, HW= 41 mm In October 2017, an adult was captured perched on leaves (approximately 2.5 m above ground), near an intermediate-sized forest pool, along Sungai Sedim trail after heavy rain. Another specimen was also observed in July 2017 at the same location, and this species denotes a new record for GIFR.

Ichthyophis sp. (Image 16)
A juvenile, approximately 15 cm long, was sighted crawling on the mud, near a forest pool and later disappeared under leaf litter. It was encountered along Sungai Sedim trail in June 2016 and represents a new record of this caecilian genus for GIFR.
Limnonectes utara is a representative of Limnonectes kuhlii species complex, and was first described by Matsui et al. (2014) from Bukit Larut, Perak. The specimen from GIFR was congruent with that of L. utara in having dense warts on the tibia, full interdigital webbing between the toes and the first finger being slightly longer than the second (Matsui et al. 2014). This finding expands the northernmost distribution of L. utara by 110 km from its type locality. Polypedates discantus is a member of Polypedates leucomystax species complex, and was described by Rujirawan et al. (2013) from Songkhla Province, southern Thailand. The morphology of the specimens found in GIFR were congruent with the description of P. discantus in having the following characters; the skin of the head does not co-ossify with the skull, and white dots on the thighs were absent (Rujirawan et al. 2013). Accordingly, the distribution of P. discantus was extended to 253 km south of its type locality. A single species of caecilian, Ichthyophis sp. was encountered. This juvenile caecilian had a yellow dorsolateral line on each side, and was not assigned to a species.
Rhacophorus nigropalmatus or Wallace's flying frog is probably not uncommon, but it is rarely encountered because of their arboreal behaviour. They only descend from the canopy during the breeding season (Dring 1979;Inger & Stuebing 1997) and prefer forest pools or animal wallows to breed (Inger & Stuebing 1997). In GIFR, R. nigropalmatus was found perched on tree branches or leaves, overhanging a stagnant water of forest pools. The intermediate-sized pool (approx. 4 m length x 2 m width) was shady and sheltered by lowland dipterocarp forest. Its water was turbid, had a muddy bed, and dead leaves and twigs accumulated at the bottom of the pool. Other frog species, such as P. leucomystax, L. blythii, and Humerana miopus were also sighted in the same pools. Tadpoles of two or three unknown frog species were also encountered in the pool. This might indicate the importance of forest pools as a breeding site for several frog species, including R. nigropalmatus. Two frog species, Hylarana doriae and Hoplobatrachus rugulosus recorded in GIFR by Ibrahim et al. (2012a) were not detected. We reviewed the material deposited by Ibrahim et al. (2012a), and we assigned the specimen they identified as H. doriae to L. blythii based on the morphological characters (large and stout body, broad head, obvious tympanum, supratympanic fold present, dark brown coloration on dorsal surface and dirty white on ventral surface). However, we could not confirmed the identity of the specimen Ibrahim et al. (2012a) assigned to H. rugulosus as the specimen was missing. To date, the only confirmed records of H. rugulosus in Malaysia are from disturbed areas in Sabah, where they are invasive (Inger & Stuebing 1989;Inger 2005). Ibrahim et al. (2012a) referred to 11 frog species encountered in GIFR as rare (P. nasutus, L. hendricksoni, D. melanostictus, L. malesianus, L. deinodon, L. plicatellus, H. erythraea, A. luctuosa, H. miopus, N. pictus, and Z. prominanus). They are not rare species but J TT are species with elusive and secretive behaviours that could otherwise be recorded with suitable /specialised sampling methods. For example, both P. nasutus and L. hendricksoni are typical forest frog species, which can be found on the forest floors of old secondary forests or primary rain forests. They are usually encountered hiding among leaf litter, under big rocks or under rotten logs (Berry 1975;Ibrahim et al. 2008;Grismer 2011). Additionally, its dorsal pattern and colouration are very similar to their surrounding environments (ground, leaf litter, and twigs), thus providing a perfect camouflage.
Duttaphrynus melanostictus and H. erythraea are frequently seen, human-commensal species living in disturbed environment where they breed in stagnant water bodies (Inger 2005;Grismer 2011). In our study, both of these species were more frequently observed around villages, chalets or toilets when compared to that within the forest reserve areas. They can also be encountered around the roadside ditches, especially after heavy downpour. Although not many individuals of Limnonectes deinodon were observed in GIFR, this species is not considered rare. They can be found if more effort and careful observation were made during sampling periods. Usually, these small dicroglossids are encountered perched on rocks or boulders, sitting on the ground or hiding under leaves along the rivulets. Humerana miopus also is not a rare species and is often found around swampy areas and forest pools in GIFR. This species is very sensitive to sound and can immediately disappear, making it very difficult to detect.
Some species of frogs were reported at nearby areas, but were not recorded in GIFR. They are Limnonectes paramacrodon which was encountered at Bukit Hijau, Tupah, and Ulu Paip, Sylvirana malayana at Bukit Perangin, Rentapia flavomaculata at Ulu Paip, and Ichthyophis nigroflavus at Bukit Perangin. Ulu Paip, Bukit Hijau, Tupah, and Bukit Perangin are located 19, 24, 75, and 151 km from GIFR, respectively. According to Inger (2003), the presence of frog species in a particular area depends on various factors, including duration of sampling period, area of coverage, sampling technique, topography, weather, microhabitats, and activity pattern. Additionally, the physical characteristics of a stream also determine the presence and absence of frog species (Inger 1969).
From this research its shows that GIFR is very rich with amphibian species. Various type of habitats in GIFR contributed to higher richness of frog diversity. These included rivers, small forest streams, swamps, ditches, forest pools, rock pools, temporary pools, tree buttress pools and animal wallows, which provided suitable sites for amphibians to live and breed. Additionally, the presence of Banjaran Bintang Hijau with several prominent peaks such as Gunung Bintang and Gunung Inas influence the landscape of this area, which lead to the diverse amphibian species. Amphibians are essential to be conserved and protected as they play many important roles in the ecosystem. They are significant as a biological indicator, to control insects, as a prey for various types of predators and as medicinal species. Current research shows that amphibians skin secretions comprise various bioactive compounds including the antimicrobial peptides (AMPs), which is effective to various strains of bacteria (Conlon et al. 2008;Al-Ghaferi et al. 2010). These AMPs are able to use as a template, to develop and produce a new therapeutic agent (Conlon & Sonnevend 2011). Thus, amphibian species are required to be totally protected, so that the natural drugs resources, which have valuable potential are preserved forever. For a strategic conservation planning, their habitats and breeding sites must be defended and restricted from human disturbances. Deforestation and forest alteration for any purpose should be minimised or totally stopped in GIFR, so as to sustain and promote the amphibian richness and other biodiversity in general.