A new species of Hemiphyllodactylus Bleeker, 1860 (Squamata: Gekkonidae) from Ba Na-Nui Chua Nature Reserve, Central Vietnam.

A new species of the gekkonid Hemiphyllodactylus banaensis sp. nov. is described from Ba Na-Nui Chua Nature Reserve in central Vietnam. Previously included within H. yunnanensis, the new species is distinguished from all other congeners by having the unique combination of a maximum SVL of 48.2 mm in males and 51.0 mm in females; seven chin scales extending transversely from the union of the first and second infralabials and posterior margin of mental; enlarged postmental scales; 9-12 supralabials; 9-11 infralabials; 18-20 longitudinally arranged dorsal scales at midbody contained within one eye diameter; 20-21 precloacal and femoral pore-bearing scales contiguous in males and 0-20 contiguous pore-bearing precloacal scales in females; dorsal pattern on body composed of transverse blotches and two whitish stripes across shoulder extending to sacrum; postsacral mark whitish brown and bearing anteriorly projecting arms; and caecum and oviducts unpigmented.

Two new species of semiaquatic freshwater crabs of the genera Tortomon and Aiyunamon from karst forests in northern Vietnam (Crustacea: Brachyura: Potamidae).

Two new genera of freshwater crabs (Potamidae) are recorded from northern Vietnam, Tortomon Huang, Wang & Shih, 2020, and Aiyunamon Pan, Ng & Sun, 2022. These genera had previously only been reported from southern China and eastern Myanmar. Each genus is represented by a new species. Tortomon distinctum n. sp. is markedly different from its two Chinese congeners in its proportionately wider carapace, more elongate third maxilliped, the carpus of the cheliped being armed only with a low tubercle, possessing relatively more slender and longer ambulatory legs, a gently curved male first gonopod and a more elongate male second gonopod. Aiyunamon vietnamicum n. sp. is distinct from its five congeners in its proportionately less convex dorsal surface of the carapace, relatively lower epigastric cristae, lower rugosities of the postorbital cristae, wider median lobe of the posterior margin of the epistome, relatively narrower male pleon, and a male first gonopod that has the terminal segment more distinctly curved with a wider concavity on the outer margin of the subterminal segment.

A new semiterrestrial crab from limestone hills in Vietnam (Crustacea: Brachyura: Potamidae: Tiwaripotamon).

A new species of semiterrestrial crab of the potamid genus Tiwaripotamon Bott, 1970, is described from limestone hills in northern Vietnam. Tiwaripotamon bellum n. sp. is one of the largest known species in the genus, and its external morphology is most similar to T. vietnamicum (Dang & Ho, 2002), described from northern Vietnam. Tiwaripotamon bellum n. sp., however, can easily be separated by its much darker colour in life, possession of a distinct epibranchial tooth on the carapace, the proportionately shorter ambulatory meri, and the gently curved terminal segment of the male first gonopod, with a subtruncate tip and dorsal lobe on the proximal part of the structure.

Six new species of the Cyrtodactylus intermedius complex (Squamata: Gekkonidae) from the Cardamom Mountains and associated highlands of Southeast Asia.

An integrative taxonomic analysis using color pattern, morphology, and 1449 base pairs of the ND2 mitochondrial gene and its five flanking tRNAs demonstrated that eight species-level lineages occur within the Cyrtodactylus intermedius complex (Cyrtodactylus intermedius sensu stricto, C. phuquocensis and related populations) of the Cardamom mountains and associated highlands that have a sequence divergence ranging 3.4-8.9%. Additionally, each lineage is discretely diagnosable from one another based on morphology and color pattern and most occur in specific geographic regions (upland areas, karst formations or islands) that prevent or greatly restrict interpopulation gene flow. Six of these lineages were masquerading under the nomen C. intermedius and are described as the following: Cyrtodactylus auralensis sp. nov. endemic to Phnom Aural, the highest mountain in Cambodia; C. bokorensis sp. nov. endemic to the Bokor Plateau, Cambodia; C. cardamomensis sp. nov. from the main block of the Cardamom mountains; C. thylacodactylus sp. nov. endemic to Phnom Dalai the northernmost peak of the Cardamom mountains; C. laangensis sp. nov. endemic to the Phnom Laang karst formation, Cambodia; and C. septimontium sp. nov. from the Bay Núi Hills of southwest Vietnam.

The systematics and independent evolution of cave ecomorphology in distantly related clades of Bent-toed Geckos (Genus Cyrtodactylus Gray, 1827) from the Mekong Delta and islands in the Gulf of Thailand.

An integrative taxonomic analysis of the distantly related Cyrtodactylus condorensis and intermedius species complexes of the Mekong Delta revealed that C. paradoxus is a junior synonym of C. condorensis and that C. thochuensis is a junior synonym of C. leegrismeri. Additionally, the analysis revealed that a cave-dwelling ecomorpholgy has evolved independently early on in the evolution of both complexes (represented by C. hontreensis in the intermedius complex and C. grismeri and C. eisenmani in the condorensis complex) and cave ecomorphs exist in sympatry-but not syntopy-with general scansorial ecomorphs. Multiple, recent, cyclical, glacioeustatic driven changes in sea levels across the Sunda Shelf are hypothesized to account for the evolution and distribution of the widely separated, conspecific insular populations of C. condorensis and C. leegrismeri. The independent evolution of cave ecomorphology is proposed to have been driven by competition avoidance. Habitat islands across the Mekong Delta are an important source of endemism and in need of protection.

Gekko aaronbaueri, a new gecko (Squamata: Gekkonidae) from central Laos.

A new species of the genus Gekko Laurenti is described from central Laos. The species is distinguished from its congeners by its moderate size, i.e. maximum SVL 80.0 mm, dorsal pattern of five to six dirty white vertebral spots alternating with yellowish-edged, W-shaped blotches between nape and sacrum and six to seven pairs of dirty white spots interspersed with yellowish-edged dark blotches on the flanks between limb insertions, 0-1 internasal, 39-43 ventral scale rows between the weakly developed ventrolateral folds, 3-4 precloacal pores in males, sometimes separated by one poreless scale, 98-104 smooth dorsal scale rows around the body, 16 broad lamellae beneath digit I of pes, 15-16 broad lamellae beneath digit IV of pes, and enlarged subcaudal scales.