Description of the final stadium larva of Anisopleura furcata Selys, 1891 (Odonata: Euphaeidae) from Thailand.

The final stadium larva of Anisopleura furcata Selys, 1891 is described and illustrated. The larva can be separated from all known Anisopleura Selys, 1853 larvae by the following characters: the profusion of elongated tubercles on the labrum and antefrons, the presence of a long bifid spur on the outer margin of the mandibles, presence of a row of claviform setae on dorsal apex of tarsus, and antennae 8-segmented. The inner lobe of the labial palps forms a tiny truncate tooth broadly similar to the condition in all other known members of the genus. Diagnostic features that separate this species from potentially syntopic euphaeid genera are discussed.

A new species of Cletocamptus Schmankevitsch, 1875 (Copepoda, Harpacticoida, Canthocamptidae) from Rayong Province, Eastern Thailand.

Cletocamptusthailandensissp. nov. was discovered in a water body at the base of a small mountain near the Phang Rat River Delta in Rayong Province, Eastern Thailand. The new species resembles C.goenchim Gómez, Ingole, Sawant & Singh, 2013 and C.koreanus Chang, 2013, but it can be distinguished from these two species based on the armament of the endopodal lobe of the male P5, ornamentations of the abdominal segments, the caudal ramus, the male P3Endp-3, and the relative length of the aesthetasc on the fourth segment of the female antennule. According to the combinations of certain female characteristics, including the number of setae on the P3Endp-2, the relative length of the caudal ramus, the relative length of the inner apical seta on the P3Endp-2, the shape of the P5, and the number of setae on the P3Exp-2, five groups of the Cletocamptus species can be defined.

Description of the larva of Indocnemis orang (Frster in Laidlaw, 1907) (Odonata: Platycnemididae: Calicnemiinae) from Thailand, with larval key to the known genera of the family Platycnemididae in Asia.

The larval characters of the genus Indocnemis Laidlaw, 1917 are described based on larval specimens of I. orang (Frster in Laidlaw, 1907) from Thailand. The larvae are characterized by 56 pairs of premental setae, 89 palpal setae of the same length, and vertical lamella caudal gills. The habitats and new provincial records of I. orang in Thailand are also provided in addition to a key to the genera of the family Platycnemididae in Asia.

Thailandorchestiarhizophila sp. nov., a new genus and species of driftwood hopper (Crustacea, Amphipoda, Protorchestiidae) from Thailand.

During a scientific survey, a new genus of driftwood hopper was found in mangrove roots in Ko Kut District, Trat Province, Thailand. We placed this new genus, Thailandorchestia gen. nov., within the family Protorchestiidae. The new genus can be distinguished from the remaining genera by uropod 1 outer ramus with robust setae, uropod 2 outer ramus without robust setae, and pereopod 7 basis without a posterodistal lobe. The type species of Thailandorchestia gen. nov., Thailandorchestiarhizophila sp. nov., is described herein, and an updated key to the genera of the family Protorchestiidae is provided.

Floresorchestia kongsemae sp. n. a new species (Crustacea: Amphipoda: Talitridae) from Kasetsart University, Bangkok, Thailand.

BACKGROUND: The genus Floresorchestia Bousfield, 1984 is widely distributed in terrestrial and marine coastal habitats. It has been found from coastal South Africa through to the Indo-Pacific region and the Caribbean Sea in Central America. Two species of Floresorchestia have been reported in Thailand, Floresorchestia boonyanusithii Wongkamhaeng et al. 2016 and Floresorchestia buraphana Wongkamhaeng et al. 2016. This work reports on a new species of Floresorchestia found at Kasetsart University in a man-made pond and neighbouring areas. NEW INFORMATION: Classification of the new species was achieved by considering the left mandible 5-dentate; gnathopod 2 posterior margin merus carpus and propodus of gnathopod 2 covered in palmate setae, palm reaching about 33% along posterior margin; uropod 3 peduncle with three robust setae; telson dorsal mid-line half the length of its breadth and four robust setae per lobe.

Theosbaena loko sp. n. a new stygobiotic microshrimp (Thermosbaenacea: Halosbaenidae) from southern Thailand.

BACKGROUND: Thermosbaenaceans are subterranean crustaceans, widespread and occur in freshwater, oligohaline or anchialine caves or thermal springs. Currently, four families, seven genera,and 45 species are recognised worldwide. During our studies of the isolated karst, Tham Loko (Loko Cave) in Khao Chiason District, Phatthalung Province, we found an undescribed thermosbanacean species in the genus Theosbaena. Theosbaena is the only genus reported from freshwater in the Oriental Region. Previously, there were only two known species, Theosbaena cambodjiana Cals & Boutin, 1985 from Kampot Province, southern Cambodia and Khon Kaen, Thailand and T. kiatwongchai Rogers & Sanoamuang, 2016 discovered in a cave of Takhli District, Nakhon Sawan, central Thailand. Our new species is the third species recorded in the Oriental Region. NEW INFORMATION: Theosbaena loko sp. n. differs from its congeners by having a telson 1.8x longer than its breadth, maxilla 1 palp distal segment 4x longer than the proximal palpomere and the maxillopodal exopod twice as long as its basal width. This microshrimp is the third described species of the genus. A key to the species is given and suggestions for the conservation status of the new species are discussed.

A review of Diplommatina species in eastern Thailand with the descriptions of five new species.

BACKGROUND: Microsnails in the genus Diplommatina Benson, 1849 from eastern Thailand are revised, based on the collection of the Zoological Research Collection, Burapha University, Chonburi Province, Thailand and on recently-collected materials. NEW INFORMATION: Five new species, Diplommatina burapha sp. n., D. chadathongae sp. n., D. chantaburiensis sp. n., D. fusiformis sp. n. and D. khwantongae sp. n., are described as new to science. The geographic distribution of these eastern species is presented.

Grandidierella gilesi Chilton, 1921 (Amphipoda, Aoridae), first encounter of non-indigenous amphipod in the Lam Ta Khong River, Nakhon Ratchasima Province, North-eastern Thailand.

The first record of the non-indigenous, alien amphipod Grandidierella gilesi in the Lam Ta Khong River is presented. Previously, this Indo-Pacific amphipod had only been reported in the Indian Ocean, the Andaman Sea, the Gulf of Thailand, the South China Sea and Australia. In Thailand, G. gilesi was previously reported in an isolated pond in Bangkok. The present study constitutes another record of this species in inland water. The characteristics and variation of G. gilesi, observed in this study, are also discussed. All the specimens described here are preserved at the Princess Maha Chakri Sirindhorn Natural History Museum, Prince of Songkla University, Songkla, Thailand.

A new species of Boholina (Crustacea, Copepoda, Calanoida) and a first record for stygobiotic calanoid fauna from a cave in Thailand.

A new species of Calanoida belonging to the genus Boholina Fosshagen & Iliffe, 1989 was found in a freshwater pool within a cave of the Satun province, South Thailand. It is the first record of the genus and of a stygobiotic representative of calanoid fauna in this country. The new species is most similar to B. crassicephala Fosshagen & Iliffe, 1989, based on position of genital pores, structures of P4 and P5 in both sexes, relative length of subapical spine vestige on the male right P5, and shape of the male left P5 endopods. However, this new species is distinguished from its known congeners by: (1) relatively longer distal outer spines on the male right P5 exopods, (2) smaller endopods of the male left P5 and (3) elongated apical spines on the distal exopodal segment of the female P4 and P5. Furthermore, the distinctive characteristic of the Thai Boholina is the presence of inner minute seta on the distal segment of the male right P5 exopod. Detailed descriptions of the new species and a key to all six known species of the genus Boholina is provided.

Discovery of a new genus and species of dogielinotid amphipod (Crustacea: Amphipoda: Dogielinotidae) from the Nipa palm in Thailand, with an updated key to the genera.

During a scientific survey, a new genus of the dogielinotid amphipoda was found in the Nipa palm (Nypa fruticans) in Bang Krachao Urban Oasis, Samut Prakan Province, Thailand. We placed this new genus, Allorchestoides gen. nov., within the family Dogielinotidae. The new taxa can be easily distinguished from the remaining genera by differences in the incisor of the left and right mandibles, apical robust setae of the maxilla 1, and the large coxa and strong obtuse palm in the female gnathopod 1. The type species of Allorchestoides gen. nov., Allorchestoides rosea n. sp., is described here in, with an updated key to the genera of the family Dogielinotidae.

Two new species of Floresorchestia (Crustacea, Amphipoda, Talitridae) in Thailand.

The beach-hopper and land-hopper genus Floresorchestia Bousfield, 1984 is most widespread in terrestrial and marine littoral habitats and has been recorded from the South African coasts through to tropical Indo-Pacific and Caribbean Sea. In Thailand, there is only Floresorchestia samroiyodensis Azman, Wongkamhaeng & Dumrongrojwattana, 2014 reported from the swamp of Prachuab Kiri Khan, southern Thailand. In this work, two new species of Floresorchestia from Phutsa Reservoir in Nakhon Ratchasima and the man-made swamp in Burapha University are described. The new species are characterised by the mandible left lacinia mobilis 4-dentate; the posterior margin of merus, carpus and propodus covered in palmate setae; the uropod 3 peduncle with two robust setae and the telson longer than broad. The characters of the specimens are described and illustrated in this paper. All specimens are deposited in the Princess Maha Chakri Sirindhorn Natural History Museum, Prince of Songkla University, Thailand.

Three New Records of Gammarid Amphipod in Songkhla Lake, Thailand.

Songkhla Lake is known as the most popular area for gammarid amphipod studies in the Gulf of Thailand. The first gammarid amphipod study was investigated in 1925 by Chilton. After that, there are various studies including diversity, ecology, and biology. In this study, gammarid amphipod in Songkhla Lake were collected from year 2010 to 2014. In this study, three newly recorded amphipods had been reported namely Hyale dollfusi Chevreux, 1911, Grandidierella megnae (Giles, 1888), and Hourstonius japonica (Hirayama, 1983) which had not been previously reported from the Thai waters. The gammarid amphipods had been catalogued. Their characteristics had been described and illustrated. All specimens were deposited at Princess Maha Chakri Sirindhorn Natural History Museum, Prince of Songkla University, Thailand.

Corophiine amphipods of the genera Chelicorophium and Paracorophium from the lower Gulf of Thailand (Crustacea, Amphipoda, Corophiidae, Corophiinae).

Two species of corophiine amphipods from Songkhla Lake, in the lower Gulf of Thailand, are described and illustrated. Chelicorophiummadrasensis (Nayar, 1950), found in the mangrove forest, has not previously been observed in Thai waters. Paracorophiumangsupanichae sp. n. is characterized by its chelate male gnathopod 2, obtuse palm with subrectangular distomedial elevation, and urosomites 1-3 free. This is the first record of the genus Chelicorophium and Paracorophium in Thai waters. All specimens are deposited in the Princess Maha Chakri Sirindhorn Natural History Museum, Prince of Songkla University, Thailand and the Museum für Naturkunde, Berlin.

Melitid amphipods from the Gulf of Thailand, with a description of Dulichiella pattaniensis, a new species.

Two species of melitid amphipod were collected from the Gulf of Thailand. Dulichiella pattaniensis is new to science, and Melitalati latiflagella Ren & Andres, 2012 has not been previously reported from Thai Waters. Dulichiella pattaniensis is characterized by male gnathopod 2 distolateral crown with 4 spines; pleonite/urosomite formula 7-7-7-5-6-2; pereopod 5-7 dactylus with 2 accessory spines. This combination of characters has not been recorded previously in the Dulichiella. The characters of the specimens are described and illustrated. All specimens are deposited in the Princess Maha Chakri Sirindhorn Natural History Museum, Prince of Songkla University, Thailand.

Maeropsis paphavasitae and Rotomelita longipropoda, two new species (Crustacea, Amphipoda) from Lower Gulf of Thailand.

Two new species of maerid and melitid Amphipoda, Maeropsis paphavasitae and Rotomelita longipropoda, respectively, collected from a seagrassbed of the Lower Gulf of Thailand, are described. Maeropsis paphavasitae is characterized by it seven teeth on the palm of gnathopod 2 and Rotomelita longipropoda can be recognized by its long gnathopod 1 propodus. Their characters are described and illustrated. All specimens are deposited at Princess Maha Chakri Sirindhorn Natural History Museum, Prince of Songkla University, Thailand and the Museum für Naturkunde, Berlin.

Three new species from the Aoridae and Maeridae (Crustacea, Amphipoda) from Thai Waters.

Four species of amphipods from the families Aoridae and Maeridae were collected from Thai Waters in 2011. Three species, Grandidierella phetraensis sp. nov., Ceradocus andamanensis sp. nov. and Parelasmopus siamensis sp. nov. are new to science and Bemlos quadrimanus (Sivaprakasam, 1970) has not been previously reported from Thai Waters. Their characters are described and illustrated. All specimens are deposited at Princess Maha Chakri Sirindhorn Natural History Museum, Prince of Songkla University, Thailand and the Museum für Naturkunde, Berlin.