Assemblages of frogs species at Balambangan Island, Sabah, Malaysia

Borneo is well known as a hotspot for biodiversity, yet species assemblages at smaller islands in the East Malaysian states of Sabah and Sarawak, are not well documented. The survey of frogs in Balambangan Island, which is situated at the west coast of Sabah, was the first attempt to look at the occurrence of frogs at smaller islands in the state. Sampling of frogs was conducted at the coastal areas of Kampung Selamat and limestone forest for four nights sampling period. Visual encounter survey and transect line were used to sample the frogs which were captured by hand. A total of seven species of 32 individuals were captured. This was only about 8% of the total species that occurs on the mainland Sabah. The island was dominated by the ranids (65%), rhacophoridae (22%) and microhylids (13%). Bufonids and megophryids were absent. The Mangrove frog, Fejervarya cancrivora (9 individuals) and the Lesser swamp frog, Limnonectes paramacrodon (8 individuals) were dominant on this island. No new species and endemism were noted on this island. The results from this preliminary study did not support the initial belief that the island contains high levels of endemism. On the contrary, the results appear to imply recent isolation from the Sabah mainland. Thus, a more detailed study including genetic diversity should be conducted to cover more areas on the main island and other smaller islands surrounding the Borneo Island and to obtain overall picture of biogeography of the frog species

Phylogenetic position of gastrostomobdellid leeches (Hirudinida, Arhynchobdellida, Erpobdelliformes) and a new family for the genus Orobdella

The leech family Gastrostomobdellidae is characterized by its possession of an agnathous and euthylaematous pharynx, a ventral gastropore and a gastroporal duct. In this study, the phylogenetic position of two gastrostomobdellid genera, Gastrostomobdella and Orobdella, was investigated using partial nucleic 18S, 28S rDNA and mitochondrial 12S rDNA sequences. Our phylogenetic analyses showed that both Gastrostomobdella and Orobdella are nested within Erpobdelliformes, but Gastrostomobdellidae is not a monophyletic taxon. Orobdella is a sister taxon of the other Erpobdelliformes taxa. The phylogenetic position of Gastrostomobdella within the clade of Gastrostomobdella, Erpobdellidae and Salifidae still remains uncertain. According to the reconstruction of the ancestral state of the pharynx in Erpobdelliformes, a euthylaematous pharynx is considered to be plesiomorphic in this taxon. Examination of Gastrostomobdella and Orobdella specimens indicates that the morphology of the gastroporal duct of Orobdella is quite different from that of Gastrostomobdella. A new family, Orobdellidae fam. nov., was therefore erected for the genus Orobdella. Orobdellidae is characterized by its possession of a generally tubular gastroporal duct, lying on the female orga

Identification keys on advertisement call characters for the genus pulchrana (anura: ranidae)in Sarawak

The Genus Pulchrana in Sarawak comprises P. baramica, P. glandulosa, P. laterimaculata, P. picturata and P. signata. Previously these species were grouped under the genus Hylarana, subgenus Pulchrana, but recent DNA studies have upgraded the species into genus Pulchrana. DNA markers are known to be expensive and time consuming. Thus, the aims of this study were to determine unique sound characteristics for species identification and develop a dichotomous key based on advertisement calls. Based on Principal Component Analysis and Discriminant Factor Analysis, the variation of the advertisement calls of Sarawak Pulchrana was found to be able to discriminate the species within the genus. Call note, pulse duration, call energy, call frequency and call intensity are all useful characters in discriminating the Pulchrana species. These useful call characters were then developed as the dichotomous keys for species identification. It is recommended that larger samples and better recordings with low background noise are needed for more accurate and stronger species discrimination and identification via bioacoustics. Key words: frog, bioacoustics, Note, dichotomous key; pulse duration, call frequenc

Notes on Advertisement Calls Playback by Three Species of Sarawakian Frogs

Male and female frogs respond differently towards advertisement calls. The fittest call will be chosen by the conspecific female to produce progenies, means that call from male to female is to ensure the survival of the species. The objective is to observe the response of both male and female frogs by playing the advertisement call to another male or female of the same species at their breeding site. The advertisement calls were recorded manually and were replayed using a speaker with built-in amplifier. The frog’s responses were then recorded in video form. Ambient temperatures were taken using data logger. The calls were analyzed to describe call characteristics. From the acoustic playback, both male and female Pulchrana glandulosa responded towards the calls. The male produces a crying-like sound while approaching playback source meanwhile the female produces a small “wik” sound. Male Pulchrana baramica responded by straining their calls and approaches the playback source. For male Kurixalus appendiculatus, the individuals responded by moving towards the sound source without calling. Results show that male of different species and male and female of the same species react differently towards playback calls. This shows that the breeding call recorded can be recognized by other frogs when they were played on amplifier

Characterisation of crude and partially purified peptides with antimicrobial activity from the skin of Bornean frogs

Antimicrobial peptides are one of the most promising antibiotic candidates with the effectiveness in killing the microorganisms, can be found largely in the frog skin. In this study, the antimicrobial properties of the crude and partially purified peptides from the frog skin of Bornean frogs; Chalcorana raniceps, Limnonectes kuhlii, Meristogenys jerboa, Odorrana hosii, Staurois guttatus and Limnonectes leporinus were determined. Crude peptides from the skins of these frogs were partially purified using C18 Sep Pak columns. The antimicrobial activities tested were disc diffusion, minimum inhibitory concentration and minimum bactericidal concentration test. L. leporinus and L. kuhlii peptides displayed the lowest MIC value against P. aeruginosa (62.5 µg/ mL) and S. typhimurium (125 µg/mL). Moreover, L. leporinus peptide showed the lowest MIC value against S. aureus (31.25 µg/mL). Both L. kuhlii and L. leporinus peptides share the lowest MBC value of 125 µg/mL against S. aureus and P. aeruginosa. Peptides from L. kuhlii exhibited the lowest MBC values against MRSA (125 µg/mL), E. coli (62.5 µg/mL) and S. typhimurium (125 µg/mL). It can be concluded that all extracted skin peptides have antimicrobial activity against the selected bacteria, with the skin peptides from L. kuhlii and L. leporinus frogs being more potent than other species studied. The antimicrobial characteristics of peptide samples imply that there is a potential of novel AMPs from the frog species of Borneo. For future study, the peptides of frog skin extracts should be further purified