
Djoko T IskandarIndonesian Academy of Sciences · Basic Sciences
Djoko T Iskandar
Dr
School of Life Sciences & Technology, ITB Bandung / Basic Sciences Commision, Indonesian Academy of Sciences
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Introduction
researcher
Publications
Publications (218)
Little is known about the effects of anthropogenic land-use change on the amphibians and reptiles of the biodiverse tropical forests of Southeast Asia. We studied a land-use modification gradient stretching from primary forest, secondary forest, natural-shade cacao agroforest, planted-shade cacao agroforest to open areas in central Sulawesi, Indone...
Aim
We investigated the biogeographical patterns of a widespread arboreal lizard found throughout Wallacea and the western Pacific islands. Wallacea contains longstanding oceanic currents that flow from the Pacific Ocean into the Indian Ocean, known as the Indonesian Throughflow. Using genetic data, we aim to estimate the timing and sequence of isl...
Davis et al. (2023a) published the descriptions of two new Bornean species of the highly speciose gekkonid genus Cyrtodactylus Gray, 1827 in the journal Zoologica Scripta. The descriptions themselves actually appeared in the online supplementary information to this paper as Appendix S1, accessible as a link under “Supporting Information” on the Wil...
We describe a new species of Cyrtodactylus from the northern lowlands and foothills of mainland New Guinea. Cyrtodactylus mamberamo sp. nov. is distinguished from all other Melanesian Cyrtodactylus except C. aaroni and C. mimikanus by the combination of moderate size (max SVL <100 mm), widened subcaudals, dorsal pattern of numerous narrow light ban...
Biogeographical reconstructions of the Indo-Australian Archipelago (IAA) have suggested recent spread across the Sunda and Sahul shelves of lineages with diverse origins, which appears to be congruent with a geological history of recent tectonic uplift in the region. However, this scenario is challenged by new geological evidence suggesting that th...
he Lombok Snake-eyed Skink, Cryptoblepharus cursor Barbour, 1911 has been recorded in South Java prior to 1940. However, information on its population on the island are scarce. This study presents new records of C. cursor from Java. Visual Encounter Survey were conducted to observe habitat selections and collect skinks as voucher specimens. South J...
Systematics and biogeography of Lesser Sunda paddy frogs
Divergence dating analyses in systematics provide a framework to develop and test biogeographic hypotheses regarding speciation. However, as molecular datasets grow from multilocus to genomic, sample sizes decrease due to computational burdens, and the testing of fine-scale biogeographic hypotheses becomes difficult. In this study, we use coalescen...
Background
Human-commensal species often display deep ancestral genetic structure within their native range and founder-effects and/or evidence of multiple introductions and admixture in newly established areas. We investigated the phylogeography of Eutropis multifasciata , an abundant human-commensal scincid lizard that occurs across Southeast Asi...
Herein, we describe a new species of terrestrially-nesting fanged frog from Sulawesi Island, Indonesia. Though male nest attendance and terrestrial egg deposition is known in one other Sulawesi fanged frog (Limnonectes arathooni), the new species exhibits a derived reproductive mode unique to the Sulawesi assemblage; male frogs guard one or more cl...
In a recent paper in Zoologica Scripta, the formal diagnoses and descriptions of two new Bornean gekkonid gecko species of the Cyrtodactylus consobrinus (Peters, 1871) complex were included in online supplementary material. Although the new nomina were associated with ZooBank registration identifiers, the supplementary document in which these LSIDs...
Divergence dating analyses in systematics provide a framework to develop and test biogeographic hypotheses regarding speciation. However, as molecular datasets grow from multilocus to genomic, sample sizes decrease due to computational burdens, and the testing of fine-scale biogeographic hypotheses becomes difficult. In this study, we use coalescen...
The Timor monitor lizard, Varanus timorensis, is unknown for its reproductive attributes in the natural habitats in the Lesser Sunda Islands, Indonesia. Timor monitors inhabit tropical forests and modified lands for agriculture with estimated breeding season between May and July. Reproductive characteristics and overall natural history of this spec...
The biota of Sulawesi is noted for its high degree of endemism and for its substantial levels of in situ biological diversification. While the island's long period of isolation and dynamic tectonic history have been implicated as drivers of regional diversification, this has rarely been tested in the context of an explicit geological framework. Her...
The microhylid genus Oreophryne reaches its greatest diversity in the New Guinea region, where more than 60 species have been documented to date. Most Oreophryne are small (<30 mm SVL) and only three species, O. anthonyi, O. idenburgensis and O. inor-nata, exceed 40 mm SVL adult body size. Here we describe a fourth large species of Oreophryne that...
Using molecular genetic data, recognised diversity within the gecko genus Cyrtodactylus has more than doubled, with many lineages that were once thought to be wide‐ranging being delimited into multiple independent species. On the Southeast Asian island of Borneo, there has been a recent renewed focus on reptile taxonomy, as genetic data have demons...
The mountains of New Guinea are home to species-rich but poorly understood communities of stream or torrent-breeding pelodryadid treefrogs. Here we describe a new species of moderately sized torrent-breeding Litoria from the mountains of Papua Province, Indonesia. The new species is most similar to Litoria dorsivena but differs from that species in...
Wallacea—the meeting point between the Asian and Australian fauna—is one of the world's largest centers of endemism. Twenty-three million years of complex geological history have given rise to a living laboratory for the study of evolution and biodiversity, highly vulnerable to anthropogenic pressures. In the present article, we review the historic...
Field biology is an area of research that involves working directly with living organisms in situ through a practice known as “fieldwork.” Conducting fieldwork often requires complex logistical planning within multiregional or multinational teams, interacting with local communities at field sites, and collaborative research led by one or a few of t...
The archipelagos of Wallacea extend between the Sunda and Sahul Shelves, serving as a semi‐permeable two‐way filter influencing faunal exchange between Asia and Australo‐Papua. Forest skinks (Genus Sphenomorphus) are widespread throughout southern Wallacea and exhibit complex clinal, ontogenetic, sexual, and seasonal morphological variation renderi...
Rivers are known to act as biogeographic barriers in several strictly terrestrial taxa, while possibly serving as conduits of dispersal for freshwater-tolerant or -dependent species. However, the influence of river systems on genetic diversity depends on taxa-specific life history traits as well as other geographic factors. In amphibians, several s...
Frogs in the family Ranidae are diverse in Asia and are thought to have dispersed to the Sahul Shelf approximately 10 million years ago, where they radiated into more than a dozen species. Ranid species in the intervening oceanic islands of Wallacea, such as Hylarana florensis and H. elberti from the Lesser Sundas and H. moluccana from eastern Wall...
Field biology is an area of research that involves working directly with living organisms in situ through a practice known as “fieldwork.” Conducting fieldwork often requires complex logistical planning within
multiregional or multinational teams, interacting with local communities at field sites, and collaborative research led by one or a few of t...
The paucity of biodiversity assessments in the Palaeotropics has constrained recommendations for tropical forest conservation in areas such as Siberut, one of the Mentawai Islands in Indonesia known for its high endemicity. Taking advantage of information from museum collections amassed from the Indo-Malaya archipelago from the early 20th century o...
Comprehensive assessments of species’ extinction risks have documented the extinction crisis and underpinned strategies for reducing those risks. Global assessments reveal that, among tetrapods, 40.7% of amphibians, 25.4% of mammals and 13.6% of birds are threatened with extinction. Because global assessments have been lacking, reptiles have been o...
Comprehensive assessments of species’ extinction risks have documented the extinction crisis and underpinned strategies for reducing those risks. Global assessments reveal that, among tetrapods, 40.7% of amphibians, 25.4% of mammals and 13.6% of birds are threatened with extinction. Because global assessments have been lacking, reptiles have been o...
Phylogenetic and multivariate analyses of Gekko smithii Gray, 1842 recover a new species Gekko hulk from Peninsular Malaysia and support the resurrection of G. albomaculatus (Giebel, 1861)
The Lesser Sunda Archipelago offers exceptional potential as a model system for studying the dynamics of dispersal-driven diversification. The geographic proximity of the islands suggests the possibility for successful dispersal, but this is countered by the permanence of the marine barriers and extreme intervening currents that are expected to hin...
Conservation status of Varanus rudicollis
Conservation status of Varanus dumerilii
The widespread parthenogenetic gecko Lepidodactylus lugubris is comprised of several clonal lineages, at least one of which has been known for some time to have originated from hybridization between its maternal ancestor, Lepidodactylus moestus, and a putatively undescribed paternal ancestor previously known only from remote islands in the Central...
Sulawesi's endemic maleo bird Macrocephalon maleo, a megapode that lays its eggs in communal nesting areas of warm sand or soil, is classified as Endangered on the IUCN Red List, with its decline generally attributed to habitat loss and poaching of its large eggs. Despite decades of protection under Indonesian law and numerous field conservation ef...
One of the most urgent contemporary tasks for taxonomists and evolutionary biologists is to estimate the number of species on earth. Recording alpha diversity is crucial for protecting biodiversity, especially in areas of elevated species richness, which coincide geographically with increased anthropogenic environmental pressures - the world's so-c...
The Lesser Sunda Archipelago consists of hundreds of oceanic islands located in southern Wallacea. The Sunda ratsnake, Coelognathus subradiatus, is endemic to the Lesser Sundas and is found on most of the major islands. Mitochondrial DNA was sequenced from snakes representing five of the major islands revealing that levels of sequence divergence be...
Despite a considerable amount of research, the systematics of the ranid genus Huia have remained unresolved, mostly owing to insufficient sampling and morphological similarities. As currently circumscribed, Huia consists of five species, but multiple studies have consistently demonstrated that it is not a monophyletic genus. However, no study has a...
Wallace's and Lydekker's Lines both describe important biogeographic barriers in the Indo-Australian Archipelago, with Wallace's Line demarcating the boundary of the Greater Sunda Shelf and Lydekker's Line indicating the edge of the Sahul continental shelf. Despite their similarities, Wallace's Line has been much more heavily studied than has Lydek...
Biodiversity studies, aside from revealing hidden species from basic, conventional methods to sophisticated technologies, also have several obstacles. Our study showed that almost all variable widespread species comprised of multiple species. On the other hand, some endemic species might be found to be a synonym of a widespread species, and a reaso...
Almost a century ago, the Swiss herpetologist Jean Roux described a new skink species, Mabuia wirzi, from a single specimen from Pulau Nias, an island on the west coast of Sumatra in Indonesia (Roux 1925). The specimen was part of a small collection of reptiles and amphibians made on Nias by the ethnologist Paul Wirz (29.v.1892–1955.i.30), who work...
Within Sundaland, the species diversity of the genus Megophrys is richest in Borneo, with some species restricted to the northern highlands of the island. On the basis of molecular, morphological and acoustic evidence, we describe a new species of large-sized Megophrys, once confused with M. nasuta. The new species Megophrys kalimantanensis sp. nov...
The Lesser Sundas Archipelago is comprised of two parallel chains of islands that
extend between the Asian continental shelf (Sundaland) and Australo‐Papuan continental
shelf (Sahul). These islands have served as stepping stones for taxa dispersing
between the Asian and Australo‐Papuan biogeographical realms. While the oceanic
barriers have prevent...
The importance of long-distance dispersal (LDD) in shaping geographical distributions has been debated since the nineteenth century. In terrestrial vertebrates, LDD events across large water bodies are considered highly improbable, but organismal traits affecting dispersal capacity are generally not taken into account. Here, we focus on a recent li...
The Lesser Sundas Archipelago is comprised of two parallel chains of islands that extend between the Asian continental shelf (Sundaland) and Australo-Papuan continental shelf (Sahul). These islands have served as stepping-stones for taxa dispersing between the Asian and Australo-Papuan biogeographic realms. While the oceanic barriers have prevented...
Aim: The Lesser Sunda Islands are situated between the Sunda and Sahul Shelves, with a linear arrangement that has functioned as a two-way filter for taxa dispersing between the Asian and Australo-Papuan biogeographical realms. Distributional patterns of many terrestrial vertebrates suggest a stepping-stone model of island colonization. Here we inv...
In 2011 and 2014, we conducted two expeditions to four islands in the Kei Island group in Maluku Province of eastern Indonesia. We documented and collected 33 species of lizards, snakes, and frogs, and after reviewing historical occurrences in the island group, we accounted for a total of 39 species present in the Kei Islands (26 lizards, 10 snakes...
In 2011 and 2014, we conducted two expeditions to four islands in the Kei Island group in Maluku Province of eastern Indonesia. We documented and collected 33 species of lizards, snakes, and frogs, and after reviewing historical occurrences in the island group, we accounted for a total of 39 species present in the Kei Islands (26 lizards, 10 snakes...
Red List Data/ Conservation Status for Cyrtodactylus quadrivirgatus
There are few examples of primary succession from tropical conditions, especially on land degraded by human activity, e.g. mine wastes. Such studies would assist in informing ecological restoration of these degraded sites. Here, a chronosequence approach was used to investigate early‐stage primary succession on overburden spoil wastes derived from...
Two new species of the dwarf litter frog genus Leptobrachella are described from North and Central Kalimantan, Indonesian part of the Borneo Island. Leptobrachella fusca n. sp. from Bulungan Regency, differs from all congeneric species in the following combination of characters: body small (SVL: 16.3 mm in a male); dorsum uniformly dark brown; side...
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 s...
ND2 sequence data for members of the Draco fimbriatus group plus 13 mitochondrial sequence reads obtained from the D. cristatellus holotype
This file includes ND2 sequence data obtained via traditional Sanger sequencing for 39 individuals representing Draco cristatellus, D. fimbriatus, D. hennigi, D. punctatus, and D. maculatus, plus 183 base pairs...
The presence of an adhesive abdominal sucker (gastromyzophory) allows tadpoles of certain species of anurans to live in fast-flowing streams. Gastromyzophorous tadpoles are rare among anurans, known only in certain American bufonids and Asian ranids. To date, Huia sumatrana , which inhabits cascading streams, has been the only Sumatran ranid known...
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 sp...
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 s...
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...
Invasions of poisonous species can cause rapid population declines among native fauna because predators are naïve and often vulnerable to these toxins. The recent invasion of Madagascar by the poisonous Asian common toad, Duttaphrynus melanostictus, has sparked international attention (Kolby, 2015), as well as research and conservation efforts to p...
Coal mine overburden (OB) materials were nutrient-poor, loosely adhered particles of shale, stones, boulders, and cobbles, also contained elevated concentration of trace metals. This condition cause OB substrate did not support plants growth. However, there were certain species that able to grow on overburden dumping site. This investigation sought...