[Ichthyology • 2026] Nanosphronemus gemma • A remarkable New Genus and Species of miniature osphronemid (Anabantoidei: Osphronemidae) from Vietnam

Nanosphronemus gemma

 Britz, Tan & Rüber, 2026

Raffles. Bull. Zool. 74; 

Abstract

 A new genus and species of miniature labyrinth fish of the family Osphronemidae, Nanosphronemus gemma, is described from Vietnam. It differs from all other genera of anabantoids by a unique dorsal- and anal-fin ray count, a unique colour pattern and a number of unique or highly unusual skeletal characters. Our molecular phylogenetic analysis indicates that Nanosphronemus is the sister group of the genus Trichopsis, the croaking gouramis. 

Key words. Anabantoidei, labyrinth fishes, miniaturisation, gourami

Nanosphronemus gemma, live colouration, not preserved, all ca. 16 mm SL in lateral view.
a, putative female above, note absence of red stripe in dorsal half; b, putative male in normal colouration, note presence of red stripe above and darker pigmentation below midlateral stripe; c, putative male in breeding colouration, note overall darker colouration of body and also fins, presence of bright red stripe and highly iridescent scales in mid-lateral stripe and below on head and body.

Nanosphronemus gemma, not preserved, all ca. 18 mm SL.
a, mature female with eggs; b, in breeding colouration and typical oblique courtship position, c, approaching bubble nest under plant leaf; d, adding air bubbles and embedding eggs into bubble nest.

Nanosphronemus, new genus  

Diagnosis. Nanosphronemus differs from all other genera in the suborder Anabantoidei by its unique count of XIX– XXI+2–3 dorsal-fin rays (vs. I–XVIII+ 4–14, rarely XIX in some specimens of Macropodus ocellatus) and XX– XXIV+4–5 anal-fin rays (vs. I–XVII+8–38, rarely XX–XXII in some specimens of Macropodus spp.), the presence (vs. absence) of a series of anteroventrally directed processes off the distal part of caudal haemal arches, Baudelot’s ligament ...

Etymology. The new genus name is derived from the Ancient Greek word, νάνος, meaning dwarf, combined with the name Osphronemus, the type genus of the family Osphronemidae, to which this new genus belongs. Gender: masculine. The name alludes to the tiny size of this new fish, which makes it one of the smallest anabantoids known to date.

Nanosphronemus gemma, new species 

 Suggested common name. Jewel Gourami.

Distribution. Unclear at present: reported from undisclosed area near Huế in Central Vietnam. 

Etymology. The species name is derived from the Latin word for jewel, ‘gemma’, alluding to the stunning colouration of sexually mature males. A noun in apposition.

 

Ralf BRITZ, Heok Hui TAN and Lukas RÜBER. 2026. Nanosphronemus gemma, A remarkable New Genus and Species of miniature osphronemid from Vietnam (Teleostei: Anabantoidei: Osphronemidae). Raffles. Bull. Zool. 74; 606–623. 

 

[Arachnida • 2025] Pinelema aurata, P. cavernalis, P. onganh, ... • Hidden in the Dark: Five New Species of Pinelema (Araneae: Telemidae) from Caves in northern Vietnam with Remarks on the Genus Diversity and Conservation

Pinelema spp. in life. 
[A-C] Pinelema onganh, new species;
[D-F] P. cavernalis, new species;
[G-H] P. aurata, new species; [I] P. huifengi, new species 

Ballarin, Nguyen & Eguchi, 2025

RAFFLES BULLETIN OF ZOOLOGY. 73: 

 Abstract 

 Five new cave-dwelling species of the genus Pinelema Wang & Li, 2012 from northern Vietnam are described based on both sexes: Pinelema onganh, new species; P. cavernalis, new species; P. huifengi, new species; and P. nagaoi, new species, from Cao Bang Province, and P. aurata, new species, from Dien Bien Province. Three of these species exhibit marked morphological adaptations to subterranean life, including the absence of eyes, depigmentation, and leg elongation. For each species, detailed images of their diagnostic characters are provided. When possible, barcode sequences of the new species are obtained and compared with published Pinelema sequences in a pairwise analysis to assess the interspecific genetic variation of the genus. The significance of Pinelema species diversity in the Southeast Asian karst regions is also briefly discussed, along with conservation challenges linked to their strict habitat requirements.

 Key words. COI barcode, conservation, diversity, Southeast Asia, subterranean environment

Pinelema spp. in life. 
A, P. onganh, new species, male holotype; B, ditto, adult female; C, ditto, juvenile;
 D, P. cavernalis, new species, male holotype; E, ditto, adult female; F, ditto, adult female with egg sac;
G, P. aurata, new species, adult female; H, ditto, adult female with egg sac; I, P. huifengi, new species, adult female.

Francesco Ballarin, Anh D. Nguyen and Katsuyuki Eguchi. 2025. Hidden in the Dark: Five New Species of Pinelema (Araneae: Telemidae) from Caves in northern Vietnam with remarks on the Genus diversity and conservation. RAFFLES BULLETIN OF ZOOLOGY. 73: 548–567. [17 October 2025]

[Crustacea • 2026] Geosesarma penrissen • A New Species of Vampire Crab of the Genus Geosesarma De Man, 1892 (Brachyura: Sesarmidae) from A montane forest in southwestern Sarawak, Malaysian Borneo

 

Geosesarma penrissen

Grinang, P. Y. C. Ng & P. K. L. Ng, 2026 

 

The Raffles Bulletin of Zoology. 74; 

Abstract 

 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. 

Key words. freshwater crab, semiterrestrial, taxonomy, lowland forest, comparative morphology

Geosesarma penrissen, new species, live colouration.
A–C, holotype male (10.6 × 10.2 mm) (ZRC 2024.0567); D, paratype male (10.7 × 10.5 mm) (ZRC 2024.0171); E, adult male, on shrub, Batu Panggah trail, photographed 2311 hrs; 6 July 2023 (not collected); F, subadult, on shrub, Batu Panggah trail, photographed 2118 hrs, 6 July 2023 (not collected).

All specimens from Sarawak. E, F, photographed by Chien Lee.

 Geosesarma penrissen, new species

Diagnosis. Carapace almost square, width-to-length ratio 1.01–1.07, lateral margins gently sinuous, subparallel (Figs. 1A, D, 2A–D, 5A, C, F, 6A, D); dorsal surface with welldefined regions, anterior regions covered with small, rounded or flattened, squamate granules (Figs. 1A, C, E, F, 2A–D, 5A, C, E, 6A, D); front deflexed, with 2 broad subtruncate lobes, separated by shallow median concavity; postfrontal, protogastric lobe prominent, sharp-edged (Figs. 1A, C, D, 2A–D, 3A, 6C, F); external orbital tooth acutely triangular, outer margins curving anteriorly, tooth directed obliquely and laterally, clearly extending beyond lateral margin of carapace (Figs. 2A–D, 5A, C, E, 6A, D). Merus of third maxilliped ...

JONGKAR GRINANG, PAUL Y. C. NG and PETER K. L. NG. 2026. A New Species of Vampire Crab of the Genus Geosesarma De Man, 1892 (Crustacea: Brachyura: Sesarmidae) from A montane forest in southwestern Sarawak, Malaysian Borneo. The Raffles Bulletin of Zoology. 74; 457–464.

[Cnidaria • 2026] Chironex blakangmati • Chironex box jellyfishes (Cubozoa: Chirodropida) in Singapore: New Species, and Range Extension of C. indrasaksajiae

Chironex blakangmati

Iesa, Ames, Yap & Huang, 2026 

 RAFFLES BULLETIN OF ZOOLOGY. 74

Abstract

 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. 

Key words. 16S rRNA, COI barcoding, marine biodiversity, phylogenetic analysis, Southeast Asia, venomous

Chironex blakangmati, new species, from Singapore.
A, live individual (paratype, ZRC.CNI.1462), lateral perradius view; B, live individual (holotype, ZRC.CNI.3014), lateral perradius view; C, cockscomb gastric saccule (sac); D, gastric cirri (gc); E, rhopalial niche front view; F, rhopalial niche side view (paratype, ZRC.CNI.1462); G, rhopalial niche side view (holotype, ZRC.CNI.3014); H, tentacle contracted with alternating brown dark bands; I, tentacle stretched; J, preserved tentacle with hollow cross section (arrow); K, pedalium with volcano pedalial canal bend (pcb) marked by arrow; L, U-shaped alternating tentacle pattern with gap marked by an arrow; M, adradial positions (ad) marked by arrows, and rhopalial niche at perradial position (per); N, gastric saccules (sac) surrounding cruciform manubrium (man); O, velarium at perradial position with frenulum (fre) arrowed, lappet terminating in simple triangular tip; P, velarium with candelabrum velarial canal pattern (holotype, ZRC.CNI.3014). rh = rhopalium, rhO = rhopalial ostium, co = convex boundary.

Chironex blakangmati, new species 

Diagnosis. Chironex with conical to cuboidal bell. Seven tentacles per pedalium, branching U-shaped alternating. Pedalial canal bend volcano shaped. Tips of velarial canals sharp towards velarial margin (Fig. 11D), with simple triangular tip at edge of velarium in perradial position (Fig. 3O & Fig. 12). Absence of velarial canals at perradial position where frenulum tapers off (Fig. 12D). 

Etymology. This species is named using Bahasa Melayu, the Austronesian language spoken in the region and the national language of Singapore, for Sentosa Island from which the animal was collected. Sentosa Island was historically referred to as “Pulau Blakang Mati”, meaning “Island of Death Behind” and, as such, “blakangmati” in denoting the geographic location is a noun in apposition. 

Iffah Iesa, Cheryl Lewis Ames, Nicholas Wei Liang Yap and Danwei Huang. 2026. Chironex box jellyfishes (Cnidaria: Cubozoa: Chirodropida) in Singapore: Chironex blakangmati, new species, and range extension of C. indrasaksajiae. RAFFLES BULLETIN OF ZOOLOGY. 74: 383–402. DOI: 10.26107/RBZ-2026-0026 [15 May 2026]

[Herpetology • 2026] Platymantis guiting • A New miniaturised Platymantis (Anura: Ceratobatrachidae) from Sibuyan and Tablas islands, Romblon Island Group, Philippines

Platymantis guiting

Meneses, Pitogo, Decena, Supsup & Brown, 2026

 lkcnhm.nus.edu.sg 

Abstract

 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. 

Key words. Sibuyan Island, elevational relief, Lahatnanguri, Philippine biodiversity, conservation, Platymantis guiting

Observed colour variation in live specimens of Platymantis guiting, new species, collected from Mt. Guiting-Guiting Natural Park.

Photos by Camila G. MENESES.

Platymantis (Lahatnanguri) guiting, new species 

Etymology. The specific epithet guiting is derived from Mount Guiting-Guiting, the highest peak on Sibuyan (and the larger Romblon Island Group), with an elevation of 2,058 m asl. This mountain is a prominent geographical feature of the region and a biodiversity hotspot at the heart of Sibuyan Island, characterised by its unique flora and fauna (Brown & Alcala, 1974; Goodman & Ingle, 1993; Nerz et al., 1997; Lit & Eusebio, 2008; Esselstyn & Goodman, 2010; Brown et al., 2011; Davis et al., 2016; Heaney et al., 2005; Rickart et al., 2005; Siler et al., 2012, 2016; Lucañas, 2021; Tautel & Dupo, 2021; Ermilov & Corpuz-Raros, 2022a, b; Meneses et al., 2022). The name honours the ecological significance of the mountain and its role in conserving locally endemic species of herpetofauna in RIG.

Camila G. MENESES, Kier Mitchel E. PITOGO, Syrus Cesar P. DECENA, Christian E. SUPSUP and Rafe M. BROWN. 2026. A New miniaturised Platymantis (Amphibia: Anura: Ceratobatrachidae) from Sibuyan and Tablas islands, Romblon Island Group, Philippines. RAFFLES BULLETIN OF ZOOLOGY. 74: 197–219. [2026-04-14]

https://lkcnhm.nus.edu.sg/rbz/a-new-miniaturised-platymantis-amphibia-anura-ceratobatrachidae-from-sibuyan-and-tablas-islands-romblon-island-group-philippines/

[Crustacea • 2026] Frodromia elegans, F. granulosa, ... • Revision of Frodromia McLay, 1993 (Brachyura: Dromiidae) and the Status of Frodromiinae Števčić, 2005

A, Frodromia atypica (Sakai, 1936),; B, F. reticulata (Sakai, 1974);
C, F. elegans, new species, holotype male, Taiwan; D, F. granulosa, new species, holotype male, Vanuatu;
 E, F, F. iners, new species, holotype male, Philippines. 

Ng, 2026 

RAFFLES BULLETIN OF ZOOLOGY. 74: 

Photographs: C, T.-Y. Chan; D, J.C.E. Mendoza; E, F, P.K.L. Ng.

Abstract

 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 Števčić, 2005, which was originally established as a tribe in Sphaerodromiinae Guinot & Tavares, 2003, and which is here redefined and rediagnosed.

Key words. sponge crab, Dromioidea, systematics, subfamily definition, new species, key to taxa, Indo-West Pacific

Colour in life. A, Frodromia atypica (Sakai, 1936), after Sakai (1936: pl. 2 fig. 1); B, F. reticulata (Sakai, 1974), after Sakai (1976: pl. 5 fig. 1);
C, F. elegans, new species, holotype male (6.6 × 7.5 mm) (ZRC 2024.0144), Taiwan; D, F. granulosa, new species, holotype male (6.5 × 7.1 mm) (ZRC 2024.0517), Vanuatu;
E, F, F. iners, new species, holotype male (6.3 × 7.0 mm) (ZRC 2024.0518), Philippines [partly covered with sand particles and debris].

Photographs: C, T.-Y. Chan; D, J.C.E. Mendoza; E, F, P.K.L. Ng.

Frodromia granulosa 

F. caileani 

F. elegans 

 F. iners

PETER K. L. NG. 2026. Revision of Frodromia McLay, 1993 (Crustacea: Brachyura: Dromiidae) and the Status of Frodromiinae Števčić, 2005. RAFFLES BULLETIN OF ZOOLOGY. 74: 332–358. DOI: 10.26107/RBZ-2026-0023  [4 May 2026]

[Invertebrate • 2026] Helobdella viridoclypus • A New free-living Leech Species (Hirudinea: Rhynchobdellida: Glossiphoniidae) from Chiang Mai, Thailand

 

 Helobdella viridoclypus

 K, Trivalairat, P. Trivalairat, Raquib & Purivirojkul, 2026

Emerald-charm leech | ปลิงสร้อยมรกต || 

 RAFFLES BULLETIN OF ZOOLOGY. 74

 Abstract

 A new species of glossiphoniid leech, Helobdella viridoclypus, is described from the northern region of Thailand, representing the first record of the genus Helobdella from the country and Southeast Asia. Its characteristics are similar to those of the type species, H. stagnalis, but can be distinguished by its transparent rice-shaped and triannulated body, cephalisation, a single pair of dark eyes, a smooth dorsal surface without papillae, rich darkgreen pigmentation on the dorsum, six pairs of crop caeca with less developed first pair and unbranched second to sixth pairs (posterior caeca), male and female gonopore separated by a single annulus, and a triangular nuchal scute pointed backwards with yellowish-green colouring around the mid-dorsal region. The phylogenetic relationships of H. viridoclypus, new species, are clarified, showing that it is monophyletic within the stagnalis species-complex clade which includes H. adiastola, H. octatestisaca, H. modesta, and the type species H. stagnalis. The new species is a free-living leech that specifically preys on invertebrates and not on humans. 

Key words. Annelida, Glossiphoniidae, Haementeriinae, jawless leech, freshwater, Huai Tueng Thao Reservoir

Order Rhynchobdellida Blanchard, 1894 

Suborder Glossiphoniiformes Tessler & de Carle, 2018 in Tessler et al., 2018 

Family Glossiphoniidae Vaillant, 1890 

Subfamily Haementeriinae Autrum, 1939 

Genus Helobdella Blanchard, 1896

Diagnosis. Small, two eyes, transparent papillae on segment, nuchal gland or scute on dorsum on VIIIa1/a2, gonopores separated by one annulus, compact salivary glands, crop with less developed first pair and unbranched second to sixth pairs of caeca, liquidosomatophagous (Blanchard, 1896; Sawyer, 1986).

 Helobdella viridoclypus, new species, live holotype (ZRC.ANN.1623).
 A, dorsal view; B, ventral view.

Helobdella viridoclypus, new species

Diagnosis. Rice-shaped, transparent body; cephalisation; a pair of large, distinctly separated, dark eyes on somite III; anterior sucker twice as large as prostomium without pits inside; central mouth in anterior sucker; triangular nuchal scute pointed backward with yellowish-green colouring around mid-dorsal region (VIIa1–a3, annuli 11–13); smooth surface without dorsal papillae; rich dark-green pigmentation on dorsum, particularly around crop caeca; lesser or almost absent pigmentation along crop; one male gonopore on XIIa1/XIIa2 (annuli 26/27); one female gonopore on XIIa2/ a3 (annuli 27/28); six pairs of crop caeca with unbranched posterior caeca; maximum body width wider than anterior and posterior suckers by four and two times, respectively.

 

Etymology. The species epithet refers to the description of the nuchal scute on the neck region, which resembles a shield and is a yellowish green colour. 

The following common names are suggested: “Emerald-charm leech” (English), “Pling soi mor ra kot” (ปลิงสร้อยมรกต) (Thai), and “Der Smaragdt-charm Plattegel” (German).

 Krittiya TRIVALAIRAT, Poramad TRIVALAIRAT, Tashfia RAQUIB and Watchariya PURIVIROJKUL. 2026. Helobdella viridoclypus (Hirudinea: Rhynchobdellida: Glossiphoniidae), A New free-living Leech Species from Chiang Mai, Thailand. RAFFLES BULLETIN OF ZOOLOGY. 74: 124–141. [23 March 2026]

[Crustacea • 2021] Macromedaeus adelus • A New Species of intertidal xanthid crab of the Genus Macromedaeus Ward, 1942 (Decapoda: Brachyura: Xanthidae) from Singapore

Macromedaeus adelus

Mendoza, 2021

RAFFLES BULLETIN OF ZOOLOGY. 69 

  x.com/Mendoza_JCE

Abstract

 Four species of marine crab (Brachyura) are reported for the first time from Singapore. Three of these have been previously reported from other localities in the Indo-West Pacific region, while one is a new species described herein. The camptandriid crab, Exagorium fidelisi Naruse, Chung & Tangah, 2015, originally described from northeastern Sabah, Malaysia, is reported from the mangroves of northern Singapore. Two xanthid crabs are newly recorded as well: Hepatoporus guinotae (Zarenkov, 1971) and Medaeops edwardsi Guinot, 1967, previously described from the Red Sea and Indian Ocean, respectively. Another xanthid crab, Macromedaeus adelus, new species, is described from the intertidal areas of Singapore. It is most similar to M. distinguendus (De Haan, 1835) and M. voeltzkowi (Lenz, 1905), primarily in having a distinctly areolated and granular carapace and having four teeth on the carapace anterolateral margin. It can, however, be distinguished from congeners by morphological features of the carapace, chelipeds, ambulatory legs, and the male first gonopods. 

Key words. Xanthidae, Camptandriidae, taxonomy, biodiversity, Macromedaeus adelus, Hepatoporus, Exagorium

Live colouration. Macromedaeus adelus, new species (ZRC 2017.0466), West Coast Park, Singapore.
A, paratype, male, 16.0 × 10.3 mm; B, paratype, male, 11.8 × 7.7 mm.

Scale bar: A, B = 5.0 mm.

Macromedaeus adelus, new species

 

Etymology. The specific epithet of the new species is derived from the Greek “adelos”, meaning “unseen, unknown, and obscure”, because the true identity of this crab remained concealed for many decades. Used as a Latin adjective.

Jose Christopher E. Mendoza. 2021. Marine Crabs new to Singapore, with A Description of A New Species of intertidal xanthid crab of the Genus Macromedaeus Ward, 1942 (Crustacea: Decapoda: Brachyura). RAFFLES BULLETIN OF ZOOLOGY. 69: 463–480. [5 November 2021]

  x.com/Mendoza_JCE/status/1456821180103462914

[Herpetology • 2026] Leptobrachium widianai • A New Species of Leptobrachium Tschudi, 1838 (Anura: Megophryidae) from Bali and East Java, Indonesia

 

 Leptobrachium widianai

 Fauzan, Smith, Amarasinghe, Farajallah, Racho, Matsui & Hamidy, 2026 

Widiana’s Litter Frog | Katak Serasah Widiana  || 

RAFFLES BULLETIN OF ZOOLOGY. 74; 

Abstract

The fauna of Indonesia's Lesser Sunda and eastern Java areas harbour lineages of Leptobrachium that have been historically assigned to L. hasseltii Tschudi, 1838. Here, using an integrative dataset—mtDNA (12S–tRNA^Val–16S; 1,979 bp), adult and larval morphology, and advertisement calls—we delimit and describe a new species from Buleleng (Bali) and Kediri (East Java). Phylogenetic analyses (ML/Bayesian) recover two well-supported clades within L. hasseltii sensu lato: (1) West–Central Java and southern Sumatra (true L. hasseltii) and (2) Bali–East Java (new species), with 16S uncorrected p-distance 3.2–5.2% to L. hasseltii. Morphologically, the new species differs from L. hasseltii by the combination of brown iris with a light-blue scleral arc (eye fully open), very large oval femoral glands (dark edged), no vomerine teeth and rictal glands, distinctive dorsal pattern (dark blotches with paired transverse bars) and ventral patterning, and tadpoles having LTRF 7(1–6)/5(1–4) versus 5(1–4)/5(1–4) in L. hasseltii. The advertisement call is an elongated series of short barks followed by low-frequency squawks and differs markedly in temporal structure from L. hasseltii. We discuss biogeographic implications and provide an IUCN preliminary assessment following current guidelines. 

Key words. Amphibia, bioacoustics, Leptobrachium hasseltii, morphology, phylogeny

Two species of Bali and Javan Leptobrachium in life.
(A, B) Adult male Leptobrachium widianai, new species, from Buleleng, Bali (MZB Amph. 33320, 32734); (C) adult male from Kediri, East Java (MZB Amph. 26959); (D) juvenile (MZB Amph. 32735);
(E) adult male L. hasseltii from Mt. Slamet, Central Java (MZB Amph. 32743); (F) adult male L. hasseltii from Cisarua, West Java (MZB Amph. 32735).

Leptobrachium widianai, new species 

Diagnosis. A medium-sized Leptobrachium (adult male SVL 36.2 mm; adult female SVL to 54.1 mm) assigned to the Leptobrachium hasseltii group (subgenus Leptobrachium sensu Matsui et al., 2010) based on iris colour pattern, femoral gland morphology, and absence of upper lip spines. Distinguished from all congeners by the following combination of characters: (1) Iris and sclera: iris uniformly brown in adults with a narrow light blue scleral arc visible when the eye is fully open (juveniles with distinctive white spot-ring on iris); (2) Femoral glands: very large, oval (occasionally circular), conspicuous, with dark surrounding pigmentation; (3) Humeral glands: present, circular, flat; (4) Dentition and projections: vomerine teeth absent; snout without projections; no dermal palpebral projection; no rictal glands; ventrolateral glandular ridges absent; no upper lip spines. (5) Digital morphology: inner palmar tubercle circular, not extending along first metacarpal; subarticular tubercles reduced, replaced by low callous pads; fingers and toes with rounded, swollen tips, lacking circummarginal grooves; toe webbing poorly developed (I 0–2+, II 0–3+, III 2+–4, IV 4–2 V); (6) Dorsal pattern: typically dark brown with large irregular blotches and paired transverse bars; sometimes with orange vertebral line or orange dots; interorbital–parietal region with darker markings; (7) Lateral and ventral pattern: lateral surfaces dark grey with scattered white granules and a distinct black spot between axilla and groin; ventrum grey to light grey, throat darker, chest densely granular with white spots; (8) Call structure: elongated series of short “barks” followed by low-frequency “squawks,” temporally and structurally distinct from L. hasseltii; (9) Larvae: LTRF 7(1–6)/5(1–4) (vs. 5(1–4)/5(1–4) in L. hasseltii), marginal papillae conical and acute.

Etymology. The specific epithet honours Mr. I Made Widiana Darma Santosa, Director of the Bali Reptile Park, whose longstanding dedication to the conservation of Indonesian reptiles and amphibians — particularly those of Bali — has significantly advanced both in-situ and ex-situ conservation awareness. The name is formed as a genitive singular noun.

 Proposed English name: Widiana’s Litter Frog; 

Proposed Indonesian name: Katak Serasah Widiana.

Muhammad F. FAUZAN, Eric N. SMITH, A. A. Thasun AMARASINGHE, Achmad FARAJALLAH, Asrael RACHO, Masafumi MATSUI and Amir HAMIDY. 2026. A New Species of Leptobrachium Tschudi, 1838 (Anura: Megophryidae) from Bali and East Java, Indonesia. RAFFLES BULLETIN OF ZOOLOGY. 74; 62–86. 

[Crustacea • 2024] Caridina maeklongensis • A New landlocked freshwater Shrimp Species (Decapoda: Atyidae) from the Mae Klong Basin, Thailand

[A–D] Caridina maeklongensis  

   Macharoenboon, Manonai & Jeratthitikul. 2024

[E, F] C. sumatrensis  De Man, 1892

RAFFLES BULLETIN OF ZOOLOGY. 72

Abstract. A newly discovered landlocked shrimp, Caridina maeklongensis, new species, is described from the Mae Klong Basin, western Thailand. The morphology of the new species resembles C. sumatrensis, from which it differs in possessing a shorter rostrum with fewer dorsal teeth, a small number of very large-sized eggs, and a greatly reduced posteromedian projection on the distal end of the telson. The molecular evidence of the mitochondrial 16S rRNA gene also supports the species status of the newly described species. This is the fifth endemic species of Caridina known from Thailand. 

Key words. crustacean, landlocked freshwater shrimp, molecular phylogeny, taxonomy, Southeast Asia

Living habitus specimens of Caridina species from the Mae Klong Basin.
A–D, Caridina maeklongensis, new species: A, paratype male, MUMNH-CAR064-4; B, paratype female, MUMNH-CAR064-1; C, paratype female, MUMNH-CAR064-15; and D, paratype female, MUMNH-CAR064-13.
 E, F, C. sumatrensis: E, male, MUMNH-CAR706-P2; and F, female, MUMNH-CAR706-P1.

Family Atyidae De Haan, 1849 

Genus Caridina H. Milne Edwards, 1837 

Caridina maeklongensis, new species

Etymology. The specific name is from its type locality, the Mae Klong Basin.

Kongkit Macharoenboon, Varitsara Manonai and Ekgachai Jeratthitikul. 2024. Caridina maeklongensis, A New landlocked freshwater Shrimp Species (Crustacea: Decapoda: Atyidae) from the Mae Klong Basin, Thailand. RAFFLES BULLETIN OF ZOOLOGY. 72: 450–468.

[Ichthyology • 2025] Sayonara flavolineata • A New Deep-water anthiadid perchlet (Perciformes: Anthiadidae) from Vietnam

 Sayonara flavolineata

Tang, Vo & Gill, 2025

  RAFFLES BULLETIN OF ZOOLOGY. 73; 

  facebook.com/TVictorCN

Abstract

 A new species of deep-water anthiadid perchlet, Sayonara flavolineata, is described from seven specimens collected off Nha Trang, southeastern Vietnam. Based on morphological features, it is assigned to a recently resurrected genus Sayonara Jordan & Seale, 1906, a former junior synonym of Plectranthias. Sayonara flavolineata, new species is distinctive in having yellow and reddish orange stripes when fresh, a horizontal dusky stripe in the middle of spinous dorsal fin, and a slightly concave dorsal profile of the head. It is further distinguished from other anthiadids by the following combination of characters: dorsal-fin rays X, 15; pectoral-fin rays 15–16; branched caudal-fin rays 8+7; lateral-line scales 31–35; circumpeduncular scales 12; predorsal scales extending anteriorly to posterior nostrils; body scales bearing basal cteni; scales present on maxilla, infraorbital, and mandibles; presence of trisegmental pterygiophores in both dorsal and anal fins; and two supraneurals. We updated and revised the record of species previously classified under Plectranthias in Vietnam. Including the new species, five species are now known from Vietnam and are reclassified to recently resurrected genera including Sayonara, Xenanthias, and Zalanthias.

Key words. taxonomy, species diversity, Plectranthias

Fresh colouration of Sayonara flavolineata, new species.
 A, holotype, OIM-E.55852 (field code: Q.01204-2), 101.1 mm SL; B, paratype, NMMB-P 41621 (field code: Q.01204-1), 107.9 mm SL.

Photos by Q. V. Vo.

CHI-NGAI TANG, QUANG VAN VO & ANTHONY C. GILL. 2025. Sayonara flavolineata (Perciformes: Anthiadidae), A New Deep-water anthiadid perchlet from Vietnam.  RAFFLES BULLETIN OF ZOOLOGY. 73; 698–708.

  facebook.com/TVictorCN/posts/25309871345346161

[Herpetology • 2025] Quasipaa phamanhi • A New Species of the Quasipaa verrucospinosa complex (Anura: Dicroglossidae) from China and Vietnam

  Quasipaa phamanhi 

Liu, Zhu, Pham, Hoang, Nguyen Vu, Hou, Mo & Rao, 2025 

大围山棘蛙 | Ếch gai sần phạm anh || Pham Anh’s Spiny Frog

   RAFFLES BULLETIN OF ZOOLOGY. 73:  

Abstract 

 A new species of the Quasipaa verrucospinosa complex is described from southern China and northern Vietnam based on morphological and molecular differences. The new species can be separated from other congeners by having a relatively short head; tympanum invisible; dorsum with thick ridges and varying sized round tubercles; supratympanic fold prominent; nuptial spines present on prepollex, fingers I–II, chest, anterolateral belly and lower part of flanks in adult males and iris pale copper. Genetically, the new species is found to diverge from the most closely related taxon, Q. verrucospinosa, by a p-distance of 3.4%, and from other species in the genus Quasipaa by 4.5%–7.5% in 16S rRNA gene sequences. 

Key words. 16S rRNA, Daweishan Mountain, molecular divergence, morphology, Phu Tho Province, taxonomy

The holotype (KIZ2025001) of Quasipaa phamanhi, new species, in life.
A, dorsal view; B, ventral view; C, lateral view of the head; D, close-up view of the palm; E, close-up view of the thumb.

Quasipaa phamanhi, new species   

Diagnosis. Size large, SVL 80.9–108.5 mm; head short, HL/SVL 0.32–0.37, broader than long, HL/HW 0.74–0.85; vomerine teeth distinct; tympanum invisible; dorsum with thick longitudinal ridges and varying sized round tubercles; supratympanic fold thick; dorsolateral fold absent; adult males with nuptial spines on prepollex, fingers I–II, chest, anterolateral parts of belly, and lower part of flanks; relative finger lengths III > I > IV > II; finger tips not expanded, toe tips slightly expanded; toes fully webbed to distal end of terminal phalanx; tibio-tarsal articulation reaching to or beyond snout tip when limb adpressed along body; iris copper on upper half and greyish on lower half in life.

Etymology. The specific epithet, phamanhi, is a patronymic noun honouring Assoc. Prof. Dr. Pham Van Anh from University of Science, Vietnam National University, Hanoi, Vietnam. The designation of this species name honours his contributions to herpetological research in Vietnam, particularly in taxonomy of the anuran species complexes. 

We propose “Pham Anh’s Spiny Frog” for the common English name, “大围山棘蛙” for the common Chinese name and “Ếch gai sần phạm anh” for the common Vietnamese name of the new species.

Shuo Liu, Meibo Zhu , Cuong The Pham, Chung Van Hoang, Truong Quang Nguyen Duong Xuan Vu, Mian Hou, Mingzhong Mo and Dingqi Rao. 2025. A New Species of the Quasipaa verrucospinosa complex (Anura: Dicroglossidae) from China and Vietnam. RAFFLES BULLETIN OF ZOOLOGY. 73: 488–503 

https://lkcnhm.nus.edu.sg/publications/raffles-bulletin-of-zoology/rbz-volumes-supplements 

[Ichthyology • 2025] Sewellia pudens • A New Species of loach (Cypriniformes: Gastromyzontidae) from Dakchung Plateau, southern Laos

Sewellia pudens  

Kottelat, 2025

 

 Raffles Bulletin of Zoology. 73; 

Abstract

 Sewellia pudens, new species, is described from the Xe Kaman watershed on Dakchung Plateau, Sekong Province, southern Laos. It is distinguished from other species of the genus in having a yellowish brown body; no markings on the fins; in males, a patch of tubercles on the snout divided longitudinally by a deep groove; no modified pelvic-fin rays with dorsal bone extension. The mouth of Sewellia and the tubercles and ornamentation on the fins of several species are described; the ‘pelvic valve’ is figured. 

Key words. Cobitoidei, loach, pectoral fin, pelvic fin, tubercles, bony extensions

Sewellia pudens, MHNG 2799.022, holotype, 49.2 mm SL, male; Laos: Xe Kaman watershed, Dakchung Plateau. Tip of axillary pelvic lobe on left side damaged.

Sewellia pudens, new species

 

Diagnosis. Sewellia pudens is distinguished from all species of Sewellia by the poorly developed patterning of the body and fins. On the body, black pigments are present in a vague midlateral stripe and 3–8 small saddles on the back, especially on caudal peduncle. Some irregular markings are also present on the body of some specimens, but not forming a clear pattern. The fins of most specimens have no colour marks, except for thin black lining along rays in the dorsal, anal and caudal fins, and, rarely, 1 or 2 faint blotches along lower edge of the caudal fin. The pectoral and pelvic fins ...

Etymology. The Latin adjective ‘pudens’ means modest, humble, reserved, discreet. It refers to the absence of conspicuous pattern on the body and fins (compared to most other species of the genus) and the absence of ostentatious modification on pectoral- and pelvic-fin rays. Pudens is indeclinable.

MAURICE KOTTELAT. 2025. Sewellia pudens, A New Species of loach from Dakchung Plateau, southern Laos (Teleostei: Gastromyzontidae). Raffles Bulletin of Zoology. 73; 304–317.

[Ichthyology • 2025] Barbucca heokhuii • A New Species of loach (Teleostei: Barbuccidae) from central Borneo

 Barbucca heokhuii

 Kottelat, 2025

 

Raffles Bulletin of Zoology. 73; 

Abstract

 Barbucca heokhuii, new species, is described from the Kahayan drainage in central Borneo. It is distinguished from the other species of the genus by its miniature size (the largest known specimen is 21.5 mm SL), a truncate to rounded caudal fin, an incomplete lateral line, and a distinctive colour pattern made, among others, of five pairs of irregular bars on the flank, narrower than interspaces, many of which may be dissociated into several small blotches. It occurs in syntopy with B. diabolica. Sexual dimorphism is reported for the first time for a member of the family; in males, the 2nd to 4th branched pectoral rays are thicker than the others and with a patch of small tubercles along their posterior edge. 

Key words. Cobitoidei, loach, miniature fish, sexual dimorphism, black water, peat swamp forest

 Barbucca heokhuii, ZRC 66766, 16.2 mm SL; Borneo, Kalimantan Tengah: Kahayan drainage.

(Photographs by Tan H. H.).

Barbucca heokhuii, new species  

 Diagnosis. Barbucca heokhuiiis distinguished from the other named species of Barbucca by having: a smaller adult size (the largest known specimen is 21.5 mm SL, vs. 37.2 in B. diabolica and 34.3 in B. elongata), a deeper body (depth at dorsal-fin origin 17–21 % SL, vs. 14–18 in B. diabolica and B. elongata); a truncate to rounded caudal fin (vs. emarginated); the lateral line incomplete, reaching to below posterior half of dorsal fin (vs. complete); absence of large tubercles on head and body (vs. presence on posterior part of flank, between above the tip of the pelvic fins and the base of the caudal fin); anus about halfway between pelvic-fin base ...

Etymology. Named for Tan Heok Hui (LKCNHM) in appreciation for his work on Southeast Asian fishes, and especially fishes of peat swamp forests and loaches of Borneo, and for the long lasting friendship, collaboration and companionship in the field. 

MAURICE KOTTELAT. 2025. Barbucca heokhuii, A New Species of loach from central Borneo (Teleostei: Barbuccidae). Raffles Bulletin of Zoology. 73; 54–66.

 Researchgate.net/publication/389338300_Barbucca_heokhuii_a_new_species_of_loach_from_central_Borneo