Evy Arida

Refining the polytypic species concept of mangrove monitors (Squamata: Varanus indicus group): a new cryptic species from the Talaud Islands, Indonesia, reveals the underestimated diversity of Indo-Australian monitor lizards

The description of a new cryptic member of the mangrove monitor (Varanus indicus) (Daudin, 1802) group from Indonesia presents a refinement of the systematic concept for a polytypic complex of closely related species. The new species is recognised on the basis of morphological and molecular evidence. It is so far known only from the type locality, the remote Talaud Islands, located between Sulawesi, Halmahera and Mindanao at the outer boundary of the Wallacea transition zone between the Oriental and Australian faunal regions. While the descriptions of several sibling and mostly sympatric species within the last 15 years have not affected the range of V. indicus, here, we demonstrate that morphologically distinct island populations represent independent evolutionary lineages and warrant specific recognition as distinct species within an evolving superspecies complex. In addition, some basic natural history information is provided for the new species based on observations at the type locality. These systematic and zoogeographic investigations reveal shortcomings in the current knowledge concerning the diversity and endemism of Indo-Australian monitor lizards, particularly within the Wallacean region.

Toxic Toad Invasion of Wallacea: a Biodiversity Hotspot Characterized by Extraordinary Endemism

(a) A map of Wallacea showing islands invaded by Duttaphrynus melanostictus in red, islands inhabited by Varanus komodoensis in blue, and localities of genetic samples in yellow points. (b) A D. melanostictus from Lombok Island. (c) Environmental niche model for the Sunda Islands clade of D. melanostictus projected into Wallacea. Green color indicates very high suitability, yellow color indicates high suitability, and orange color indicates moderate suitability.

Squeezing water from a stone: high-throughput sequencing from a 145-year old holotype resolves (barely) a cryptic species problem in flying lizards

We used Massively Parallel High-Throughput Sequencing to obtain genetic data from a 145-year old holotype specimen of the flying lizard, Draco cristatellus. Obtaining genetic data from this holotype was necessary to resolve an otherwise intractable taxonomic problem involving the status of this species relative to closely related sympatric Draco species that cannot otherwise be distinguished from one another on the basis of museum specimens. Initial analyses suggested that the DNA present in the holotype sample was so degraded as to be unusable for sequencing. However, we used a specialized extraction procedure developed for highly degraded ancient DNA samples and MiSeq shotgun sequencing to obtain just enough low-coverage mitochondrial DNA (721 base pairs) to conclusively resolve the species status of the holotype as well as a second known specimen of this species. The holotype was prepared before the advent of formalin-fixation and therefore was most likely originally fixed with ethanol and never exposed to formalin. Whereas conventional wisdom suggests that formalin-fixed samples should be the most challenging for DNA sequencing, we propose that evaporation during long-term alcohol storage and consequent water-exposure may subject older ethanol-fixed museum specimens to hydrolytic damage. If so, this may pose an even greater challenge for sequencing efforts involving historical samples.

On the occurrence of Varanus nebulosus (Gray, 1831) (Squamata: Varanidae) on Riau Archipelago, Indonesia

The occurrence of Varanus nebulosus (Gray, 1831) on Sumatra still remains open for debates, while records are limited, especially those associated with a voucher specimen. The oldest record of V. nebulosus that is associated with a specimen, i.e. SMF 11554 is dated back to 1889 and presumably from Bengal (“Bengalen”), which now lies around Bangladesh. The specimen is kept at Senckenberg Museum Frankfurt (SMF) in Germany. We collected specimens from two islands in the Riau Archipelago, just west of Sumatra and provided new distribution data for this protected species of Monitor lizard in Indonesia. The two recent records represent populations of V. nebulosus other than those already known in the literature and are among the closest known occurrences to Sumatra. We suggest that islands in the Riau Archipelago might have been the stepping stones for a historical dispersal of this species from mainland Southeast Asia and Singapore.

Figure 1 In Cyrtodactylus Tahuna Sp. Nov., A New Bent-Toed Gecko (Reptilia: Squamata: Gekkonidae) From Sangihe Island, North Sulawesi, Indonesia

Cyrtodactylus tahuna sp. nov. is a new bent-toed gecko we describe herein based on three specimens from Sangihe, North Sulawesi, Indonesia, an island situated in the northern corner of the Wallacea biodiversity hotspot. The new species is a medium sized Cyrtodactylus with a SVL of up to 78.5 mm in adult males and 79.2 mm in females. It is easily distinguished from all but four species (Cyrtodactylus fumosus, C. halmahericus, C. papuensis, and C. tambora) occurring on Sulawesi as well as in the Moluccas and the Lesser Sunda Islands, by possessing precloacal and femoral pores, enlarged precloacal and femoral scales, and lacking transversely enlarged median subcaudal scales. It differs from C. fumosus by the presence of tubercles on the ventrolateral fold, more unkeeled dorsal tubercles (19 versus 4-7) and a pit-like precloacal depression in males (versus groove in males); from C. halmahericus by presence of smaller scales between the enlarged precloacal and femoral scales (versus a continuous series of enlarged precloacofemoral scales) and a continuous series of precloacofemoral pores, as well as the presence of a pit-like precloacal depression in male (versus groove in males), from C. papuensis by possessing a pit-like precloacal depression in males (versus a groove ); and from C. tambora by the presence of tubercles on the dorsal surface of the brachium and the possession of femoral pores. Our contribution, along with several other recent descriptions of bent-toad geckos from Southeast Asia, clearly indicating that the diversity of the genus Cyrtodactylus in Indonesia is still underestimated.

The Origin Of Varanus: When Fossils, Morphology, And Molecules Alone Are Never Enough

One of the many interesting questions in evolutionary studies of varanid lizards is the origin of the genus Varanus. The fossil record indicates the earliest emergence of this genus on Gondwana, although the remains of early varanid lizards have been discovered in Laurasia. The relationships among extant Varanus can generally be inferred using molecular phylogenetic techniques, although several attempts to generate a phylogeny of Varanus have used morphological characters. We identify two key-regions of global dispersal for varanid lizards that may be used to test hypotheses on the origin of this genus in a phylogeographic framework. The landmass currently connecting Africa and Asia as well as the Lesser Sunda Islands in southern Wallacea may have facilitated intercontinental radiation of varanid lizards, which are distributed in Africa, Asia, and Australia. We consider that an integrated approach such as phylogeography might better explain the origin of this charismatic lizard group than any single analytical method. Biawak, Vol. 4 No. 4. 2010. P: 117-124

A Coconut-Eating Monitor Lizard? On An Unusual Case Of Frugivory In The Melanistic Sulawesi Water Monitor (Varanus Togianus)

During field work on Selayar Island off the coast of southwest Sulawesi, an adult male specimen of the melanistic Sulawesi water monitor (V. togianus) was found dead on a road south of the village of Benteng (6°7’10.73’’ S, 120°27’59.88’’ E) on 6 June 2006. The specimen had a snout-vent-length of 56.5 cm with the tail measuring 79.3 cm. Its head exhibited clear evidence from a lethal accident with a vehicle, while the remaining body showed no injuries. The specimen was collected to be examined in detail. In order to preserve and deposit it at the Museum Zoologicum Bogoriense (MZB Lac. 5951, field number K208), the venter was opened to remove all stomach contents and prey items. Surprisingly, no prey remains were recovered from the digestive tract, but instead an unidentifiable mass comprised of countless small pieces of a whitish hard substance. After flushing and cleaning, closer examination revealed that these were small pieces of coconut flesh and had filled out the body cavity of the lizard. Although the stomach contents of other voucher specimens of water monitor lizards collected from different localities on Sulawesi have not been investigated, some specimens disgorged the remains of scorpions, chicken, and sea turtle eggs when handled for examination. The coconut pieces of the Selayar specimen, however, represent the only case of frugivorous remains recorded. The Herpetological Bulletin Vol. 139. 2017. P: 41-42

A new species of Lepidodactylus (Reptilia: Squamata: Gekkonidae) from the Kei Islands, Maluku, Indonesia

Lepidodactylus pantai is a new species of gecko from the Kei Islands, Maluku, Indonesia that is closely associated with intertidal habitats. This species does not fit cleanly into any of the three species groups described for the genus because it possesses the unique combination of both divided terminal scansors on all toes and a nearly completely cylindrical tail without fringes or evidence of dorsoventral compression. A phylogenetic analysis including this species demonstrates that it is the sister taxon of a population from Palau, and that this clade is sister to the clade containing Group III species for which we have molecular data.

Impacts of anthropogenic pressures on the contemporary biogeography of threatened crocodilians in Indonesia

The Greater Sunda region of South-east Asia supports a rich diversity of economically and ecologically important species. However, human pressures are reshaping contemporary biogeography across the region. Megafaunal distributional patterns have been particularly affected because of deforestation, poaching and human–wildlife conflict. Crocodilians are at the centre of these conflicts in Indonesia and yet remain poorly studied across much of the archipelago. We conducted population surveys of salt-water crocodiles Crocodylus porosus and false gharials Tomistoma schlegelii in Sumatra, and examined whether crocodile abundance and distribution are correlated with variations in human disturbance, fishing pressure, and habitat type. We then used these data to model remaining suitable habitat for T. schlegelii across South-east Asia. We found that abundance of T. schlegelii and C. porosus was correlated with distance from human settlements, and fish-trapping pressure. We recorded the presence of T. schlegelii in a river system in which it was previously unknown, thus expanding the known range of the species. We also found that the predicted remaining suitable habitat for T. schlegelii in Indonesia is largely limited to areas of low human activity. From these empirical and modelling approaches we propose several key conservation priorities: (1) eliminate the use of fish traps in remaining patches of T. schlegelii habitat, (2) prioritize crocodile population surveys in remaining suitable habitat, particularly in remote areas, (3) consider T. schlegelii to be potentially Endangered locally in Sumatra, and (4) expand existing reserves around the Lower Kampar River and Berbak National Park/Sembilang National Park areas of Sumatra.