FIRST REPORT ON THE FEEDING BEHAVIOR OF EARLESS MONITOR, LANTHANOTUS BORNEENSIS AND ITS PREDATION ON RICE FIELD FROG, FEJERVARYA LIMNOCHARIS IN A CAPTIVE ENVIRONMENT

Being endemic to Borneo, the Earless monitor, Lanthanotus borneensis (Steindachner, 1878) is rarely found in its habitats due to its cryptic behavior. We provide care for confiscated animals in the Reptile House of Museum Zoologicum Bogoriense (MZB) in Cibinong, West Java, Indonesia since 2014. Little is known on its natural prey but from scattered descriptive reports. This study is aimed at documenting the feeding behavior of ten captive Earless monitors and events of predation on frogs. We set up two experiments, one with meat of Rice Field Frog, Fejervarya limnocharis, and the other with live frog of the same species. Our recorded observations ran for four weeks for the frog meat feeding experiment and followed by the frog predation experiment. Our results showed that lizards constantly accepted frog meat. Lizards tended to feed before sunset for a short period of time on the muddy soil surface, although a few individuals inconsistently fed under water. The average body mass for these lizards increased by 4.29 g and average SVL by 0.45 cm. We recorded predation on frogs in three out of ten individuals observed during this study. If F. limnocharis is confirmed to occur in the natural habitats of L. borneensis, it is possible that this frog species is among the natural prey for Earless monitors. Further studies on its natural diets should be conducted to gain in-depth knowledge essential for generating effective captive husbandry for this nationally protected species in Indonesia.

ZINC CONTAMINATION IS AN UNDERESTIMATED RISK TO AMPHIBIANS: TOXICITY EVALUATION IN TADPOLES OF FEJERVARYA LIMNOCHARIS

Aquatic environments are often contaminated with zinc. Amphibian tadpoles are likely to be exposed to high concentrations of zinc present in these environments. We determined the acute and sub-chronic toxicity of ZnCl2 on Fejervarya limnocharis tadpoles under laboratory conditions. The LC50 values of ZnCl2 were found to be 5.81, 4.32, 3.79 and 3.61 mg/L at 24, 48, 72 and 96 h of exposure respectively. Long-term exposure to sub-lethal concentrations of ZnCl2 induced significant mortality in concentration and time dependent manner. Sub-lethal ZnCl2 exposure significantly altered survival, body length and body weight at metamorphosis. Micronucleus test and comet assay indicated the genotoxic potential of ZnCl2. Significant increase in DNA strand break was observed following ZnCl2 exposure equivalent to 1% of the of 24 h LC50 value. The findings indicate possible adverse to tadpoles inhabiting aquatic environments contaminated with zinc. In addition, the findings may be extrapolated to aquatic organisms of similar torphic status.

Brevinin-2GHk, a Peptide Derived from the Skin of Fejervarya limnocharis, Inhibits Zika Virus Infection by Disrupting Viral Integrity

Several years have passed since the Zika virus (ZIKV) pandemic reoccurred in 2015–2016. However, there is still a lack of proved protective vaccines or effective drugs against ZIKV. The peptide brevinin-2GHk (BR2GK), pertaining to the brevinin-2 family of antimicrobial peptides, has been reported to exhibit only weak antibacterial activity, and its antiviral effects have not been investigated. Thus, we analyzed the effect of BR2GK on ZIKV infection. BR2GK showed significant inhibitory activity in the early and middle stages of ZIKV infection, with negligible cytotoxicity. Furthermore, BR2GK was suggested to bind with ZIKV E protein and disrupt the integrity of the envelope, thus directly inactivating ZIKV. In addition, BR2GK can also penetrate the cell membrane, which may contribute to inhibition of the middle stage of ZIKV infection. BR2GK blocked ZIKV E protein expression with an IC50 of 3.408 ± 0.738 μΜ. In summary, BR2GK was found to be a multi-functional candidate and a potential lead compound for further development of anti-ZIKV drugs.

Scanning Electron Microscopic Study of Aplectana Duttaphryni Sou, Sow and Nandi, 2014 from A New Frog Host, Fejervarya limnocharis in West Bengal

Aplectana duttaphryni Sou, Sow and Nandi, 2014 was first reported in Kulti, Asansol coal-mine region, West Bengal from a toad, Duttaphrynus melanostictus (Schneider, 1899) only using light microscope. Present article describes, A. duttaphryni in details collected from the rectum of an anuran frog, Fejervarya limnocharis (Gravenhorst, 1829) in Birbhum district, West Bengal. Aplectana duttaphryni is reported for the first time from Birbhum district, West Bengal. The parasites identified by its lanceolate shaped gubernaculum, presence of 1 pair of similar and equal spicules and also with the presence of 3 pairs of preanal papillae, 2 pairs of adanal papillae, 13 pairs of postanal papillae and single papillae on the upper lip of anus. In the present study, Birbhum district recorded as new geographical locality and F. limnocharis recorded as a new host.

Seasonal Variation in Gut Microbiota Related to Diet in Fejervarya limnocharis

Organisms adapt to environmental fluctuations by varying their morphology and structural, physiological, and biochemical characteristics. Gut microbiome, varying rapidly in response to environmental shifts, has been proposed as a strategy for adapting to the fluctuating environment (e.g., new dietary niches). Here, we explored the adaptive mechanism of frog intestinal microbes in response to environmental changes. We collected 170 Fejervarya limnocharis during different seasons (spring, summer, autumn, and pre-hibernation) to study the compositional and functional divergence of gut microbiota and analysed the effects of seasonal feeding habits and body condition on intestinal microorganisms using 16S rRNA high-throughput sequencing, Tax4Fun function prediction analysis, and bioinformatics analysis. The results showed no significant dietary difference in various seasons and between males and females. However, a significantly positive correlation was detected between dietary diversity and food niche width. Host condition (body size, body mass, and body condition) also revealed seasonal changes. The frogs were colonised by 71 bacterial phyla and dominated by Proteobacteria, Firmicutes, and Bacteroidetes. Stenotrophomonas was the most abundant genus in the Proteobacteria. The composition, diversity, and function of intestinal microorganisms in different seasons were significantly different. Significant differences were observed in composition and function but not in the microbial diversity between sexes. Furthermore, seasonal foods and body mass were significantly correlated with gut microbial composition. Our results suggest that gut microbiomes of F. limnocharis vary seasonally in response to diet under fluctuating environments.

Hydrosphere occupancy modeling (ψ) and Akaike (AIC) habitat model selection of urban amphibian in West Java landscape

Amphibians are animal that requires combinations of hydrosphere (riparian vegetation, water body) and vegetation (trees) microhabitats. In urban settings, those microhabitats are scarce and disappearing. One of areas that still have sufficient microhabitats to support amphibian populations is located in an 88.9 Ha urban forests of Universitas Indonesia Campus in West Java. Here, this paper aims to assess and model the several amphibian species occupancy (Ψ) with vegetation covers, riparian vegetation, and water bodies based on Akaike habitat selection (AIC) indices. The studied amphibian species include Bufo melanosticus, Hylarana nicobariensis, Fejervarya limnocharis, and Polypedates leucomystax. For modeling, 7 microhabitat models were developed and tested for amphibian species occupancy with covariates including vegetation cover, riparian vegetation, and water body microhabitats. The Principle Component Analysis (PCA) shows that the occupancies of amphibian were influenced mostly by the presences of water bodies followed by riparian vegetation, and vegetation covers. According to the values of Ψ and AIC, Polypedates leucomystax and Fejervarya limnocharis were species that have high occupancy in riparian vegetation microhabitats with Ψ values of −14.18 and −12.59. Likewise, Hylarana nicobariensis has an equal occupancy in vegetation, riparian vegetation, and water body microhabitats. While Bufo melanosticus shows high occupancy in vegetated microhabitats (Ψ = −14.18) rather than in riparian vegetation and water bodies (Ψ = −8.79). The combinations of riparian vegetation and water bodies show higher occupancy (Ψ = −8.00) rather than Ψ(vegetation cover+water body = −5.64) and Ψ(vegetation cover+ riparian vegetation = −4.36) combinations.

The breeding biology of Fejervarya limnocharis complex, F. multistriata (Hallowell, 1861) in Mizoram, northeast India

The breeding behavior of Fejervarya multistriata was studied from the selected study sites in Mizoram for over three years between 2016 and 2019. In natural condition, breeding took place in group. The advertisement call of males consisted of a series of notes emitted at an interval of 0.1–0.4 s where the frequency spectra had a dominant band at 2670.1172 Hz and the band width ranges from 2497.8516–28422.3828 Hz. Morphometric measurements showed that females are larger than males with snout-vent length of 45.55 ± 1.54 mm vs 33.77 ± 1.03 mm, respectively. The clutch sizes ranges from 488 to 1035. We found that the calculated ‘t’ value 0.03 is less than the ‘p’ value, i.e. 1, therefore there is no correlation between SVL of females and clutch sizes.

Prey items of some amphibians and reptiles in Phu Khieo–Nam Nao Forest Complex, northeastern Thailand

Thongproh P, Chunskul J, Rongchapho P, Chuaynkern C, Chuaynkern Y, Srisonchai R, Saengsri C, Aonpime P, Phochayavanich R, Kanishthajata P, Phusaensri S, Prompalad S, Tongpun S, Arkajag J, Duengkae P. 2020. Prey items of some amphibians and reptiles in Phu Khieo–Nam Nao Forest Complex, Northeastern Thailand. Biodiversitas 21: 4124-4130. We reported prey items for two amphibians (Fejervarya limnocharis and Sylvirana nigrovittata) and three reptiles (Hebius sp., Bungarus candidus and Xenopeltis unicolor) from several areas of Phu Khieo–Nam Nao Forest Complex (northeastern Thailand) based on direct observation method. Fejervarya limnocharis (Anura: Dicroglossidae) consumed Amynthas sp. (Clitellata: Megascolecidae) in Nam Nao National Park (Phetchabun Province), while Sylvirana nigrovittata (Anura: Ranidae) consumed Megaustenia sp. (Gastropoda: Ariophantidae) in Phu Long Forest (Chaiyaphum Province). Consumption of snails in Sylvirana nigrovittata was documented as the first report on this prey item for the species. In Phu Luang Wildlife Sanctuary (Loei Province), Hebius sp. (Serpentes: Colubridae) consumed Fejervarya limnocharis while Bungarus candidus (Serpentes: Elapidae) consumed Argyrophis muelleri (Serpentes: Typhlopidae). Xenopeltis unicolor (Serpentes: Xenopeltidae) consumed Glyphoglossus molossus (Anura: Microhylidae) in Phu Wiang National Park (Khon Kaen Province).