Two venomous box jellyfish species of the genus Chironex Southcott, 1956 (Cnidaria: Cubozoa: Chirodropida) were collected from Singapore's coastal waters: Chironex indrasaksajiae Sucharitakul, 2017 and a novel species described herein as Chironex blakangmati, new species. Chironex indrasaksajiae was collected from both the Johor and Singapore Straits around mainland Singapore. Chironex blakangmati, new species, was collected from Sentosa Island along the Singapore Strait and is the fourth species described in the genus. While C. blakangmati's volcano-shaped pedalial canal and tentacle number are similar to C. yamaguchii Lewis & Bentlage, 2009, its elongated, sharp-tipped velarial canals and DNA sequences distinguish it from other Chironex species. Comparisons of Chironex blakangmati, new species, with C. yamaguchii and C. fleckeri reveal novel morphological differences at the terminal end of the perradial lappet along the velarium edge, where C. blakangmati, new species, lacks velarial canals extending from the perradial lappet terminus. Juvenile Chironex yamaguchii specimens were examined and ontogenetic variations of velarial canals are herein reported. Preliminary cnidome analysis reveals eight types of nematocysts observed in C. blakangmati, new species, five types in C. indrasaksajiae, and five types in C. yamaguchii. Molecular phylogenetic reconstruction places C. blakangmati, new species, in a clade distinct from its congeners, as sister group to C. yamaguchii based on 16S rRNA gene analysis but diverging earlier than the clade comprising C. yamaguchii and C. indrasaksajiae based on cytochrome c oxidase subunit I gene analysis for which sequence data are comparatively limited. Understanding the biodiversity and seasonality of venomous cubomedusae will help mitigate the risk they pose to human health and safety during maritime activities.
Ratufa affinis is a large, arboreal squirrel originally described from Singapore by Thomas Stamford Raffles in 1821. Although the holotype specimen has long been believed to be housed in the Natural History Museum in London (NHMUK), examination of the type specimen revealed that it belongs to a different species: Callosciurus concolor. Further searches failed to discover a true holotype specimen in NHMUK that could be positively identified as Ratufa affinis, ultimately leading us to the conclusion that the holotype is no longer extant. This necessitated the designation of a neotype, accompanied by a morphological re-description, as the type is also the nominotypical subspecies of the species. We hereby designate ZRC 4.4097 collected from Pulau Ubin, Singapore in 1923 by Reggeng as the neotype specimen of Ratufa affinis.
This study examined a small collection of hypselostomatids from limestone karsts in Feuang District, Vientiane Province, central Laos, comprising two species. A new species, Bensonella hunlaman, is described. It differs from all congeners by its white translucent shell, elongated upper palatal plica, and infrapalatal knob. Additionally, Hypselostoma loei Panha & Prateepasen, 2005, previously recorded only from northeastern Thailand, was collected and redescribed based on comparison with the topotypic specimens. The cytochrome c oxidase subunit I (COI) sequences of both species are reported herein for the first time. Molecular phylogenetic analysis confirmed the validity of a new species by recovering it as a monophyletic group, and supported the new record of H. loei, which broadens its known distribution from Thailand into Laos.
The final instar larva of Risiophlebia dohrni (Kr & uuml;ger, 1902) (Odonata: Libellulidae) is described for the first time based on specimens collected from lowland freshwater swamp forests in Singapore. The larva is characterised by elongate antennae exceeding head length, small compound eyes, and well-developed middorsal and posterolateral abdominal spines. Comparative examination with related Southeast Asian libellulid larvae indicates that Risiophlebia possesses a distinctive combination of characters not observed in other described genera. These findings provide useful diagnostic features for larval identification and contribute to improving comparative larval taxonomy of Southeast Asian Libellulidae. The species inhabits shallow stagnant pools in swamp forest habitats, highlighting the importance of conserving these localised wetland environments.
The Labroides phthirophagus Randall, 1958 and Labroides bicolor Fowler & Bean, 1928 species complexes of cleaner wrasses are reviewed. The former comprises three colourful, phylogenetically intractable species confined to tropical coral reefs in the Indo-Pacific, viz., Labroides phthirophagus from the Hawaiian Islands, Labroides rubrolabiatus Randall, 1958 from the central and southeastern Pacific, and Labroides pectoralis Randall & Springer, 1975 from the western Pacific. Our phylogenomic analysis of genome-wide ultraconserved elements and mitochondrial DNA resolves four taxa within this complex, with one taxon, Labroides flammulatus, new species, described as a new, cryptic species from the eastern Indian Ocean. Labroides flammulatus, new species, is described on the basis of eight specimens, the holotype and four paratypes from Christmas Island, and three paratypes from the Cocos (Keeling) Islands. A second species, Labroides inopinatus, new species, is described on the basis of six specimens, the holotype and two paratypes from Flora Reef, Coral Sea, and one paratype each from the Izu Oceanic Park in Japan, Holmes Reef in the Coral Sea, and Boulari Pass in New Caledonia. Labroides inopinatus, new species, appears to be widespread across the western Pacific but is restricted to deep mesophotic coral reefs below 40 m. The new species is highly distinctive and appears to be only distantly related to Labroides bicolor. The recent synonymy of Larabicus quadrilineatus within Labroides is corroborated by morphological and phylogenomic evidence, and the species is reinstated as Labroides quadrilineatus (R & uuml;ppell, 1835), following the historical combination first established by G & uuml;nther in the nineteenth century. New ecological and field observations are provided for Labroides, and phylogenetic relationships for the new species, congeneric species of Labroides, and related genera of labrichthyine wrasses are explored. Labroides is rediagnosed and a key to species is provided.
A new species of semiterrestrial crab, Geosesarma penrissen, new species, is described herein from Mount Penrissen in southwestern Sarawak, Malaysia. It represents the third species of Geosesarma known from the montane forests of Borneo, the other two being G. larsi Ng & Grinang, 2018 from Mount Ampungan in Serian, Sarawak, and G. aurantium Ng, 1995 from Mount Silam in Sabah. Diagnostic characters distinguishing G. penrissen, new species, from its congeners are provided, together with ecological notes on its highland habitat.
A new species of operculated land snail in the genus Pupina, is described from Cat Tien National Park, Dong Nai Province, Vietnam. Pupina cattienensis, new species, is the ninth species of the genus in Vietnam and differs from its congeners in having a more bulging last whorl, more whorls, parietal tooth completely covering the posterior canal, and an extension of the apertural lip next to the anterior canal. An updated distribution of Pupina species from Vietnam is also provided.
Neobrettus tibialis (Pr & oacute;szy & nacute;ski, 1978) is a small spartaeine jumping spider (3-4 mm) commonly found in curled, dried banana leaves across South-east Asia. The species exhibits pronounced sexual dimorphism: females are hairier and more brightly coloured, whereas males are comparatively duller. Here we provide the first detailed description of intraspecific interactions in N. tibialis. We identified 38 distinct behavioural elements across inter-and intrasexual encounters. During intersexual encounters, males consistently initiated courtship, expressing a diverse repertoire of displays that closely resemble those of other salticids. Females were usually passive observers or decamped but occasionally chased or pounced at males. In male-male and female-female encounters, fewer behavioural elements were expressed, and no direct physical contact was observed. Despite the female's distinctive, hairy, mould-like appearance, the intraspecific behavioural repertoire of N. tibialis closely resembles that of other salticids. These findings establish a behavioural baseline for N. tibialis, contributing to our understanding of courtship and agonistic displays in Spartaeinae and offering broader insights into the evolution of intraspecific communication in jumping spiders.
Velutinomiris, a new genus of the mirine plant bug (Mirinae: Mirini) ranging from the Oriental Region to Wallacea, is proposed to accommodate five new species, namely, V. aungsani, new species (Shan, Myanmar), V. makassar, new species (South Sulawesi, Indonesia), V. palawanus, new species (Palawan, Philippines), V. phorcopterus, new species (Luzon, Philippines), and V. taiwanicus, new species (Taiwan, including the Lanyu Islands). These new taxa are considered representatives of the Adelphocoris-Adelphocorisella-Phytocoris group, and their taxonomic positions are discussed. A key is provided to distinguish all congeners of our new genus.
The island of Borneo, situated within the Indo-Australian Archipelago, is recognised as hosting the highest marine biodiversity on Earth today. However, the evolutionary history of fish biodiversity in this region remains poorly understood due to a sparse fossil record and a paucity of detailed taxonomic studies. This study presents the first fossil fauna of Siluriformes from Sarawak (Malaysian Borneo), comprising sea catfish (Ariidae) and eeltail catfish (Plotosidae). The material forms part of a Pleistocene/Holocene vertebrate fossil assemblage, which has been reworked and redeposited along the beach, recently discovered on Bruit Island in the Rajang River Delta. The assemblage comprises a mix of aquatic (e.g., bony fish, sharks) and nonaquatic (terrestrial mammals) fauna, with fish remains predominating, particularly the ariid catfishes, which represent the most common rayfinned fish fossils at the site. To facilitate the identification of the catfish fossils, we collected 13 extant ariid and plotosid species from Brunei and Sarawak and prepared their skeletal specimens for anatomical comparison, with a primary focus on skull allometry. The fossil material encompasses over 200 bones, including numerous cranial elements along with postcranial bones such as pectoral and dorsal spines, as well as vertebrae. Additionally, several fossilised ariid otoliths (lapilli) were recovered. Our taxonomic identification of these fossils indicates the presence of at least four ariid species: Hexanematichthys sagor, which was the most abundant, followed by Plicofollis nella, Kyataphisa nenga, and Arius cf. maculatus, and one plotosid species, Plotosus cf. canius. The habitat of the fossil catfish fauna from Sarawak is best attributed to a coastal marine and estuarine palaeoenvironment, analogous to modern transitional environments, such as the Rajang River Delta.
A study of a large collection of freshwater crabs from northern Vietnam yielded 12 new species of the I. erythreum, I. falx, I. hamyenense, I. lacertosum, I. thienkense, I. angustum, I. septentrionum, and I. yensonense. The species are differentiated by characters of the overall carapace shape, anterolateral armature, male thoracic sternum, male pleon and structures of the male first gonopod.
Fifteen species belonging to the families Camptandriidae Stimpson, 1858, Macrophthalmidae Dana, 1851, and Varunidae H. Milne Edwards, 1853 are reported from the soft-bottom substrates of the Lesser Sunda Islands, Indonesia. Paramoguai kavieng Ahyong, 2014 (Camptandriidae) and Metaplax tredecim Tweedie, 1950 (Varunidae) are recorded for the first time from Indonesian waters. One new species of Macrophthalmidae, Macropthalmus (Macrophthalmus) atambua, is described and illustrated. The new species is characterised by a very broad carapace, with the surface densely tuberculate, and long, slender chelipeds with the cutting margin of the fingers armed with spines.
The taxonomy of Trichoptera larvae in Southeast Asia has been poorly studied, with only 39 species in nine families described. In the present study, COI gene sequences were analysed with distance-and tree-based delimitation methods to associate larvae and adults of six known species of Chimarra, namely C. akkaorum Malicky & Chantaramongkol, 1989; C. bimbltona Malicky, 1979; C. khamuorum Chantaramongkol & Malicky, 1989; C. moira Malicky & Prommi, 2004; C. okuihorum Mey, 1998; and C. usal Malicky & Chantaramongkol 1998. Species-matched larvae were then further examined for species-diagnostic morphological characters. Larvae of the six species can be distinguished at least by the shapes of their heads, the anterior margin of the frontoclypeal apotome, the submental sclerites, the mandibles, the posterolateral margins of pronota, the presence/absence of a notch anteromesally on the T-shaped labrum, and the position of seta s18. Sharing of certain morphological characteristics between species within the same larval groups supports the early division of adult species groups. In addition, a key to known Chimarra larvae of Thailand is provided. Moreover, in this work, we observed some possible cryptic species among the adults. This study demonstrates how DNA can be useful tools for matching caddisfly larvae to adults, facilitating their subsequent description and improving the state of knowledge of regional Trichoptera.
Free-living marine nematodes are small ubiquitous roundworms that inhabit nearly every ecosystem but are not well studied in several parts of the world. We collected sediment samples from two locations in the Strait of Singapore and analysed the nematode diversity with microscopy and molecular methods. The study revealed the presence of 20 genera previously unrecorded in the Singapore Strait, and two new records from Southeast Asian sediments, as well as an unusual abundance of epistrate-feeders.
The taxonomy of the West Pacific dromiid genus, Frodromia McLay, 1993, is revised using a suite of characters pertaining to the carapace form and armature, proportions of the ambulatory dactylus, and structures of the pereopods, thoracic sternum, male pleon, and gonopods. The identity of the poorly known type species, F. atypica (Sakai, 1936), is clarified and the species is rediagnosed and illustrated based on the single non-type dried specimen available. Frodromia reticulata (Sakai, 1974) is also rediagnosed on the basis of a series of Japanese specimens. The material identified as F. atypica by McLay (1993) from New Caledonia and the Indonesian Moluccas is here shown to belong to two new species, F. granulosa and F. caileani, respectively; with F. granulosa also reported from Vanuatu. Two other new species, F. elegans and F. iners, are described from the South China Sea and the Philippines, respectively. As a result, Frodromia is hereby classified in the subfamily Frodromiinae & Scaron;tev & ccaron;i & cacute;, 2005, which was originally established as a tribe in Sphaerodromiinae Guinot & Tavares, 2003, and which is here redefined and rediagnosed.
The BORNEENSIS Collection, housed at the Institute for Tropical Biology and Conservation (ITBC), Universiti Malaysia Sabah, in northern Borneo, is one of the most important biological repositories in Southeast Asia. The collection, set up in 1996 and consisting of the Herbarium (BORH) and the Zoological Collections (BOR), was established with the goal of becoming a key reference collection for Bornean flora and fauna, especially those native to Sabah, that supports and assists biodiversity research and education. We provide a comprehensive account of the history of the collection, its current management status and holdings, and its roles in supporting local and international biodiversity and biosystematics research, undergraduate and postgraduate education and training, and in supporting non-formal educational outreach activities. Building on the experiences and challenges faced by BORNEENSIS thus far, we provide recommendations for the continued relevance of BORNEENSIS in terms of the continuity of collections care and management, promoting equitable specimen-based research and collections-based education and training, strengthening outreach efforts, and learning from our counterparts via improved networking.
We provide the first formal description of the tadpole of the megophryid frog, Leptobrachella murphyi, based on specimens collected from its type locality on Doi Inthanon, Chiang Mai Province, northern Thailand. The larvae were found in small mountain streams, inhabiting sandy substrates with accumulated leaf litter. Taxonomic confirmation was achieved using a combination of morphological characteristics and molecular sequencing of the mitochondrial 16S rRNA gene fragment. The tadpole of L. murphyi possesses the characteristic morphology of the genus, indicative of a semi-fossorial or fossorial lifestyle. The larva can be identified by a distinctive colour pattern on the body and tail, a cylindrical sinistral spiracle, a bevelled vent tube, and a specific tooth row formula of I:2+2/2+2:I. The study results also reveal key diagnostic differences between L. murphyi and its sympatric congener, L. korifi.
We describe a new species of miniaturised Platymantis (subgenus Lahatnanguri) from the Romblon Island Group (RIG), Philippines. Previously, the RIG population was treated as Platymantis pygmaeus, a forestdwelling species endemic to Luzon Island due to morphological, ecological, and acoustic similarities. We conducted phylogenetic analyses using 16S mitochondrial DNA sequences and quantified morphological variation across a statistically robust sample size to assess the distinctiveness of the RIG population. Our results recovered the RIG lineage as monophyletic with moderate support (75% bootstrap; 0.83 BPP). Phylogenetic analyses further demonstrate that Platymantis guiting, new species, is not closely related to P. pygmaeus and it is morphologically distinguished by shorter limb proportions and a stereotyped advertisement call characterised by a single-pulsed, repetitive clicking. Named after Mount Guiting-Guiting, the highest peak on Sibuyan Island, this species stands as a powerful reminder of the biogeographic subregion's fragile and irreplaceable biodiversity. This taxonomic revision highlights the unique herpetological diversity of the RIG and reinforces the need for targeted conservation efforts in this biogeographically significant subregion.
The distinctive green ghost crab, Ocypode celadon, was recently described from material from the Unfortunately, because the journal is an electronic-only publication and the work did not include a ZooBank registration number, the name is not available for nomenclatural purposes. The present note validates the name Ocypode celadon by fulfilling the requirements of the current zoological code.
A total of 454 ophiuroid specimens were collected from beaches surrounding the public lagoons at Sentosa Island, Singapore, during a marine biodiversity survey in May 2023. They belong to seven species and three genera in two families, Ophiactidae and Ophiotrichidae. The most abundant species were Ophiactis savignyi found in sponges, and Ophiothela mirabilis observed amongst sponges, sea grass, and algae. Ophiothrix (Ophiothrix) plana is transferred to Macrophiothrix based on molecular evidence, with SEM observations of isolated dorsal arm plates providing morphological support for this reassignment. All seven species were previously reported from deeper waters around Singapore; this is the first time they have been documented from artificial structures in shallow-waters of reclaimed beaches. Findings from this study provide a baseline that will be useful for further biodiversity monitoring along modified coastal shores.
