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Snakebite envenoming is one of the neglected tropical diseases and is still rarely studied in Indonesia. The high diversity of venomous snakes in Indonesia is one of the challenges. To overcome this, we consider that snake venomic research guided by phylogenetic relationships can serve valuable information that may contribute to snakebite mitigation. Here, we briefly introduce our recent study using HPLC-MS/MS to analyse the venom composition and variation across four Indonesian Trimeresurus. This adds more information on venom variation among Trimeresurus species within the close geographic origin, which congruent with their phylogenetic relationships. We also conducted a preliminary study to detect intraspecific variation between the venom of males and females of T. puniceus using SDS-PAGE. There is an addition of protein with a molecular weight of 13 kDa in the venom of male T. puniceus, while a protein with a molecular weight of 16 kDa is only detected in female venom. We summarize recent studies showing different factors that can affect venom variation between and within snake species. Finally, we discuss the importance of transdisciplinary research to understand snake venom variation and suggest future directions, particularly from a herpetological view, to mitigate human-snake conflict in Indonesia.

Global demand for the water monitor's skin, Varanus salvator, has made it a valuable wildlife commodity. Leathercraft manufacturing must consider not only beauty but also the strength and flexibility of the leather, which is determined by its structure in the skin. Therefore, this study analyzed and evaluated the fiber type characteristic of the water monitor's skin. Skin samples were collected from 10 Sumatra water monitors with a Snout-Vent Length size of 39-89 cm and were divided into small (39-59 cm) and large (60-89 cm) groups. The skins from the dorsocervical, lumbosacral, and ventral regions were proceeded for histological sections. Histochemical approaches utilized were Hematoxylin Eosin, Picrosirius Red, and Elastin Verhoeff's Hematoxylin staining methods. Thick fibers are the main component in the skin, ranging from 69-73%, respectively, while thin fibers varied greatly and were observed predominantly in the reticular dermis. Fiber size in the reticular dermis of small lizards was lower than that of larger ones. Elastic fibers were observed abundantly at the border of the reticular dermis and subcutaneous layer in both small and large lizards. Moreover, the skin of the small-sized lizard also has a lower morphometric than that of a large-sized lizard, both in thickness and fiber type percentage. Therefore, the skin of small-sized lizards was considered less tough than that of large-sized lizards. [ABSTRACT FROM AUTHOR]

Lectin is often used to investigate the differentiation and maturation of spermatogenic cells in the testes of several wild animals, facilitating the screening of mature individuals. Therefore, this study aimed to determine spermatogenesis activity using lectin histochemistry in water monitor lizards (Varanus salvator) harvested from the wild. Testes of 43 comprehensively examined water monitor lizards were collected from slaughterhouses in Palembang (Sumatra) and Banten (West Java), Indonesia, with snout-vent lengths (SVL) ranging from 39 to 96 cm. Additionally, histologic, histomorphometric, periodic acid-Schiff (PAS) staining, and lectin histochemistry (Con A, RCA, WGA, PNA, VVA, DBA, UEA-I) observations were performed. The results showed a positive correlation between SVL, morphometry, and histomorphometry at p < 0.05 with Pearson's correlation analysis. All specimens presented a spermatogenesis process with different activities among various SVL sizes, with larger animals having higher spermatogenic activity. Moreover, PAS-positive reactions in the testes were mainly observed in the cytoplasmic residues of spermatogenic cells, connective tissue, Leydig cells, and blood vessels. The most dominant-reacting lectin bindings were ConA, RCA, and WGA, distributed in nearly the entirety of the testes, including in spermatids and spermatozoa phases. PNA and VVA bindings were localized in Golgi and Cap stage spermatids, while UEA-I and DBA lectins showed no binding reaction. Although the larger animals had more spermatogenic cells, the lectin-binding patterns of all specimens were similar. The presence of lectin binding of PNA, VVA, and WGA in spermatids and spermatozoa in spermatogenic cells signified that male monitor lizards harvested from the wild exhibited active spermatogenic processes and were able to produce mature spermatozoa. [ABSTRACT FROM AUTHOR]

New Guinea is the largest tropical island in the world and hosts immense endemic biodiversity. However, our understanding of how the gradual emergence of the terrestrial ecosystems of the island over the last 40 Myr has generated this biological richness is hampered by poorly documented species diversity and distributions. Here, we address both these issues through an integrative taxonomy and biogeographical approach using Hylophorbus , a New Guinea-endemic genus of frogs with 12 recognized species. We delimited candidate species by integrating mitochondrial DNA, nuclear DNA, and bioacoustics, then investigated their evolutionary history. Our results suggest that the current taxonomy of the genus misses true species diversity by ≥3.5-fold. Nevertheless, most candidate species (27) remain unconfirmed because of missing data, whereas five were identified unambiguously as undescribed (we describe three of these formally). Time-calibrated phylogenetic analyses suggest that Hylophorbus diversification began ~9 Mya in the northern or eastern portion of New Guinea. It would appear that lineages dispersed to new terrestrial habitats in the west, notably uplifted by the central range orogeny, until eventually reaching the Bird's Head during the Mio-Pliocene (7–5 Mya). Conversely, a past barrier appears to have prevented north–south dispersal. These data suggest that new habitat availability has primarily driven the diversification of Hylophorbus. [ABSTRACT FROM AUTHOR]

We revise the systematics of the ranid frogs of the genus Hylarana occurring on Halmahera Island, Northern Moluccas of eastern Indonesia based on molecular and morphological data. Our results show that two distinct species each being nested within two distinct clades (hereafter papua clade and celebensis clade) exist on the island. One corresponds to H. moluccana (celebensis clade) and the other one to an unnamed species (papua clade) that we describe herein. The new species is genetically distinct from all congeners of the papua clade by p distances ranging from 6.9% to 11.5% on the 16S rRNA gene. Morphologically, the new species can be distinguished from all congeners by having the following combination of characteristics: A large species with adult males reaching a maximum snout-to-vent length (SVL) 67.3 mm; vomerine teeth in two oblique rows with narrow interodontophore distance; snout rounded dorsally; dorsum with few scattered cone-shaped tubercles that are black with white tips; distinct skin folds (ridges) on the dorsal side of the thigh coinciding with dark brown cross bars; a marbled pattern on the ventral side of thigh and yellowish groin. Here we provide a redescription for H. moluccana based on its lectotype from Ternate. We also provide new occurrence records for H. daemeli, H. volkerjane, and H. arfaki from the western part of mainland Papua. Furthermore, we demonstrated that H. celebensis harbors multiple mtDNA lineages suggestive of cryptic diversity within the celebensis clade. The occurrence of two distinct species from Halmahera calls for further research on the biogeographic history of Hylarana in Northern Moluccas. [ABSTRACT FROM AUTHOR]

Two of the six Chirixalus species currently known are distributed in Indonesia. Both species are only known to be distributed in Java, and they are Chirixalus trilaksonoi and Chirixalus pantaiselatan. During two field expeditions conducted in 2022 in Palembang, South Sumatra, we encountered several individuals exhibiting morphological similarities to C. trilaksonoi. Subsequent analysis, encompassing molecular, morphological, and bioacoustic, was undertaken to ascertain the identity of these individuals. The analyses outcomes unequivocally confirm that the specimens from Palembang are indeed C. trilaksonoi. Nevertheless, slight variations were observed between the Javanese and Sumatran populations of C. trilaksonoi. These populations exhibited a low genetic distance of 0.6% in mitochondrial DNA and displayed three polymorphic sites. Furthermore, there are slight differences in various morphological characteristics, and in advertising calls. The IUCN red-list status of this species was also evaluated, and based on the available evidence, we propose C. trilaksonoi as Vulnerable according to criteria B1ab(iii). This study stresses the importance of comprehensive taxon studies, especially in neighboring island, and in one biogeographical region. [ABSTRACT FROM AUTHOR]

The Litoria graminea group currently consists of seven nominal species of large, predominately green canopy-associated treefrogs from New Guinea and surrounding islands. Here, we first describe a character that appears to diagnose this species group from the similarly large and green Litoria infrafrenata group, specifically nuptial pads comprised of relatively large asperities versus more numerous and tiny asperities. We then describe a new species of this group from the Wondiwoi Mountains at the base of the Wandammen Peninsula in Indonesian New Guinea. The new species differs from other members of the Litoria graminea group in aspects of body proportions, extent of hand webbing, colouration, and size and shape of the male nuptial pad. Discovery of this new species emphasises the until-recently overlooked pattern of multiple co-occurring species of large, green and highly arboreal Litoria in lowland and foothill rainforest areas across much of New Guinea. Over 40 species of frogs were documented in the vicinity of the type locality, emphasising the high species richness of forests on the Wandammen Peninsula. [ABSTRACT FROM AUTHOR]

Background: Several studies have been published on the characterization of Trimeresurus venoms. However, there is still limited information concerning the venom composition of Trimeresurus species distributed throughout Indonesia, which contributes to significant snakebite envenomation cases. The present study describes a comparative on the composition of T. albolabris, T. insularis, T. puniceus, and T. purpureomaculatus venoms originated from Indonesia., Methods: Protein content in the venom of four Trimeresurus species was determined using Bradford assay, and the venom proteome was elucidated using one-dimension SDS PAGE nano-ESI- LCMS/MS shotgun proteomics., Results: The venom of T. albolabris contained the highest protein content of 11.1 mg/mL, followed by T. puniceus , T. insularis and T. purpureomaculatus venom with 10.7 mg/mL, 8.9 mg/mL and 5.54 mg/mL protein, respectively. In total, our venomic analysis identified 65 proteins belonging to 16 protein families in T. purpureomaculatus ; 64 proteins belonging to 18 protein families in T. albolabris ; 58 different proteins belonging to 14 protein families in T. puniceus ; and 48 different proteins belonging to 14 protein familiesin T. insularis. Four major proteins identified in all venoms belonged to snake venom metalloproteinase, C-type lectin, snake venom serine protease, and phospholipase A2. There were 11 common proteins in all venoms, and T. puniceus venom has the highest number of unique proteins compared to the other three venoms. Cluster analysis of the proteins and venoms showed that T. puniceus venom has the most distinct venom composition., Conclusions: Overall, the results highlighted venom compositional variation of four Trimeresurus spp. from Indonesia. The venoms appear to be highly similar, comprising at least four protein families that correlate with venom's toxin properties and function. This study adds more information on venom variability among Trimeresurus species within the close geographic origin and may contribute to the development of optimum heterologous antivenom., Competing Interests: Competing interests : PT Bio Farma (Persero) has financially supported the present study and authors ARS, LR, NS, HB, Maharani and AA are linked to this institution.