Concerted and Independent Evolution of Control Regions 1 and 2 of Water Monitor Lizards (Varanus salvator macromaculatus) and Different Phylogenetic Informative Markers

Duplicate control regions (CRs) have been observed in the mitochondrial genomes (mitogenomes) of most varanids. Duplicate CRs have evolved in either concerted or independent evolution in vertebrates, but whether an evolutionary pattern exists in varanids remains unknown. Therefore, we conducted this study to analyze the evolutionary patterns and phylogenetic utilities of duplicate CRs in 72 individuals of Varanus salvator macromaculatus and other varanids. Sequence analyses and phylogenetic relationships revealed that divergence between orthologous copies from different individuals was lower than in paralogous copies from the same individual, suggesting an independent evolution of the two CRs. Distinct trees and recombination testing derived from CR1 and CR2 suggested that recombination events occurred between CRs during the evolutionary process. A comparison of substitution saturation showed the potential of CR2 as a phylogenetic marker. By contrast, duplicate CRs of the four examined varanids had similar sequences within species, suggesting typical characteristics of concerted evolution. The results provide a better understanding of the molecular evolutionary processes related to the mitogenomes of the varanid lineage.

Dietary Correlates of Oral and Gut Microbiota in the Water Monitor Lizard, Varanus salvator (Laurenti, 1768)

Numerous studies have demonstrated that food shapes the structure and composition of the host’s oral and gut microbiota. The disorder of oral and gut microbiota may trigger various host diseases. Here, we collected oral and gut samples from wild water monitor lizards (Varanus salvator) and their captive conspecifics fed with bullfrogs, eggs, and depilated chicken, aiming to examine dietary correlates of oral and gut microbiota. We used the 16S rRNA gene sequencing technology to analyze the composition of the microbiota. Proteobacteria and Bacteroidota were the dominant phyla in the oral microbiota, and so were in the gut microbiota. The alpha diversity of microbiota was significantly higher in the gut than in the oral cavity, and the alpha diversity of oral microbiota was higher in captive lizards than in wild conspecifics. Comparing the relative abundance of oral and gut bacteria and their gene functions, differences among different animal groups presumably resulted from human contact in artificial breeding environments and complex food processing. Differences in gene function might be related to the absolute number and/or the taxonomic abundance of oral and gut microorganisms in the wild and the water environment. This study provides not only basic information about the oral and gut microbiota of captive and wild water monitor lizards, but also an inference that feeding on frogs and aquatic products and reducing human exposure help water monitor lizards maintain a microbiota similar to that in the wild environment.

Diet reflects opportunistic feeding habit of the Asian water monitor (Varanus salvator)

The Asian water monitor (Varanus salvator) is a large generalist predator and scavenger lizard. This species has a widespread distribution throughout South and Southeast Asia and is frequently encountered around the edges of urban settlements. Here, we present information on diet diversity and habitat utilisation of a population of Asian water monitors inhabiting the University of Malaysia Terengganu campus located on the east coast of mainland Malaysia. The stomach contents of 30 Asian water monitors were examined by stomach flushing, and 47.6% of stomach contents was mangrove crab, 26.2% was human waste and 26.2% was other natural foods consisting of fruits, fishes, leeches, snails, birds and insects. We then recorded the locations and habitats utilised by patrolling the campus area and found Asian water monitors preferred to use water and mangrove forest habitats that fringed and crisscrossed the campus. The broad diversity of stomach contents reflected food available at this location and indicates the opportunistic feeding habit of this species. Given that this species widely distributed in Southeast Asia, its broad diet diversity and habitat variations may promote the adaptation of Asian water monitor to different environments.

The critical role of natural forest as refugium for generalist species in oil palm-dominated landscapes

In Borneo, oil palm plantations have replaced much of natural resources, where generalist species tend to be the principal beneficiaries, due to the abundant food provided by oil palm plantations. Here, we analyse the distribution of the Asian water monitor lizard (Varanus salvator) population within an oil palm-dominated landscape in the Kinabatangan floodplain, Malaysian Borneo. By using mark-recapture methods we estimated its population size, survival, and growth in forest and plantation habitats. We compared body measurements (i.e. body weight and body length) of individuals living in forest and oil palm habitats as proxy for the population’s health status, and used general least squares estimation models to evaluate its response to highly fragmented landscapes in the absence of intensive hunting pressures. Contrary to previous studies, the abundance of lizards was higher in the forest than in oil palm plantations. Recruitment rates were also higher in the forest, suggesting that these areas may function as a source of new individuals into the landscape. While there were no morphometric differences among plantation sites, we found significant differences among forested areas, where larger lizards were found inhabiting forest adjacent to oil palm plantations. Although abundant in food resources, the limited availability of refugia in oil palm plantations may intensify intra-specific encounters and competition, altering the body size distribution in plantation populations, contrary to what happens in the forest. We conclude that large patches of forest, around and within oil palm plantations, are essential for the dynamics of the monitor lizard population in the Kinabatangan floodplain, as well as a potential source of individuals to the landscape. We recommend assessing this effect in other generalist species, as well as the impact on the prey communities, especially to reinforce the establishment of buffer zones and corridors as a conservation strategy within plantations.

Landscape transformation and wildlife: road mortality in Rawa Aopa Watumohai National Park, Southeast Sulawesi, Indonesia

The development of high way that crosses wildlife habitat will inevitably cause wildlife casualties. The purpose of this study was to identify wildlife road mortality in Rawa Aopa Watumohai National Park, Southeast Sulawesi (mostly consisted of savanna). Road kill data was collected by driving along the 22.4 km highway in February and March 2020 (n=28). Traffic volumes were recorded by taking traffic samples in 5 different times of the day, an hour duration each (totaling 70 h). There were 37 species being killed (totaling 529 individuals, of which 49.3% happened along km 0-10), consisted of 19 bird species, 3 small mammal species, 10 reptile species, and 5 amphibian species. Based on taxa, the highest number of road mortality was amphibians (dominated by Ingerophrynus biporcatus), followed by birds (mostly Lonchura malacca), mammals (dominated by Rattus argentiventer), and reptiles (dominated by Varanus salvator). Among mammals, no big mammal (booted macaque Macaca ochreata, wild boar Sus scrofa) was killed. Landscape transformation clearly has impacted wildlife in the study area. To reduce the occurrence of road kills, it is recommended to create corridors for wildlife crossings, limiting vehicle speed in the hot spots locations, create speed bumps, as well as adding more signage and road signs along the highway.

Herpetofauna diversity and distribution based on the elevational range in West Java, Indonesia

Erawan TS, Jauhan J, Husodo T, Wulandari I, Fauzi DA, Megantara EN, Shanida SS. 2021. Herpetofauna diversity and distribution based on the elevational range in West Java, Indonesia. Biodiversitas 22: 4308-4319. The herpetofauna discovery in West Java is still low and has not yet described the herpetofauna community's species diversity entirely and thoroughly in West Java. It experiences high anthropogenic impacts both from infrastructure and tourism activities. If left further, herpetofauna species will become extinct locally because of anthropogenic factors. Therefore, it is essential to reveal the diversity and distribution of herpetofauna species. This study aimed to show diversity and distribution based on the elevational range in West Java. Visual Encounter Survey in combination with the Auditory Encounter Survey was applied in this study. We found 74 species where the Colubridae family were found most commonly in the study sites. Of 74 species, four species have high conservation status, including Rhacophorus reinwardtii, Ophiophagus hannah, Varanus salvator, and Malayopython reticulatus. Besides, ten species were found to be endemic to Java and Java-Bali. Based on elevation, herpetofauna is mainly located at elevations < 1000 m asl. The higher the height, the fewer the number of species found. In Amphibians, the highest number of species tend to be found at 400-1200 m asl and 1400-1700 m asl, while reptiles tend to be located at 400-900 m asl. Keywords: Auditory Encounter Survey, West Java

Sparganosis (Spirometra spp.) in Asian Water Monitor (Varanus salvator): A medical implications for veterinarians, breeders, and consumers

Background and Aim: The high prevalence of sparganosis has been reported globally, especially in Asian countries where the majority of individuals consume raw meat from wild-caught reptiles. In Indonesia, similar cases regarding the high prevalence of sparganosis were recorded from wild reptiles such as snakes that utilized for culinary purposes, whereas, there are no data regarding other species such as water monitor lizard (Varanus salvator), which also provided as daily culinary with a high number of trades. Therefore, this study aims to investigate the prevalence of sparganosis in water monitor lizard (V. salvator), which is frequently utilized as culinary products in East Java Province, Indonesia. Materials and Methods: A total of 313 living wild-caught and captive-bred Asian water monitor lizards were collected from the reptile markets and breeders. All samples were euthanized and observed for the presence of plerocercoid. Identification of the plerocercoid as larval infective stage was made using carmine staining method. Results: The total prevalence of sparganosis was recorded at 69.64%. A total of 393 plerocercoids were collected in which divided 280 (71.24%) infecting muscles and 113 (28.75%) located in subcutaneous tissues. Conclusion: To the best of our knowledge, this study not only recorded as the first evidence but also confirms the role of monitor lizards as sparganosis transmitters in Asia and reveals additional routes of sparganosis transmission in Indonesian reptiles. Local conservation laws should be strengthened to effectively control or ban wildlife trade in traditional markets. Moreover, public awareness regarding sparganosis as a neglected zoonotic disease should be applied to prevent disease transmission in Indonesia.

Beliefs in the Dietary Benefits of Water Monitor, Varanus salvator Meat in Western Java, Indonesia

Local knowledge on the benefits of wild meat is probably the motivation behind consumption of such unusual source of protein. Various tribes in Indonesia are known to include wild meat of monitor lizards, Varanus spp. in their diet for several reasons including health benefits. Water monitor, Varanus salvator, is widely distributed across the Indonesian Archipelago and commonly found even in degraded habitats. Meat and internal organs of this species are commonly known to be consumed in Indonesia by at least three ethnics, i.e. Batak on Sumatra, Dayak on Kalimantan, and Minahasa on Sulawesi islands. We aim to investigate consumption of water monitor meat in a few communities in the western part of Java, where there is likely a custom albeit benign. Previous observations in the province of West Java showed consumption of a smaller scope in Sundanese communities, where religious background is of a restriction. Consumption of water monitor meat all over on Java seemed to be infrequent, yet also prevailing at a level of small business. In the western part of Java, consumption and sales seemed to be dominant in the northern areas, but mostly in Jakarta than in the regencies of West Java province. Direct observations and casual interviews with a few associates in West Java revealed a long-term practice in Cibinong. Besides its gastronomic benefit, meat of water monitor is believed as health tonic for men and a therapeutic method to treat skin diseases.