[Crustacea • 2022] Floresorchestia amphawaensis & F. pongrati • Two New Species of the Genus Floresorchestia (Amphipoda: Talitridae) from Amphawa Estuary, Samut Songkhram Province, Thailand

FA. Floresorchestia amphawaensis sp. nov.  
FP. F. pongrati sp. nov.  
Amphawa District, Samut Songkhram, Thailand. 

Suklom, Keetapithchayakul, Rahim & Wongkamhaeng, 2022

DOI: 10.3897/zse.98.83749

Scale bars: 1 mm 

Abstract

Two new species of Floresorchestia (Crustacea: Amphipoda) are described from Amphawa Estuary, Samut Songkhram Province, Thailand. Floresorchestia amphawaensis sp. nov. is a riparian-hoppers living near agricultural and urban areas, being distinguished by the following character states: left mandible lacinia mobilis 4-dentate; gnathopod 2 palm reaching about 34%; telson as broad as long, with four robust setae per lobe. Floresorchestia pongrati sp. nov. are described as riparian-hoppers living in the moist area near Mae Klong canal banks with a unique left mandible lacinia mobilis 5-dentate; gnathopod 2 palm reaching 30% and telson with seven robust setae per lobe. The status and the problem of diagnostic character states of the genus Floresorchestia are discussed.

Key Words: Floresorchestiinae, riparian-hoppers, Southeast Asia, Talitridae

Male habitus of Floresorchestia spp. 
FA. Floresorchestia amphawaensis sp. nov. holotype, male, 7.8 mm (THNHM-lv-18763), Amphawa District, Samut Songkhram, Thailand; 
FP. F. pongrati sp. nov. holotype, male, 10 mm (THNHM-lv-19369), Amphawa District, Samut Songkhram, Thailand.

 Scale bars: 1 mm (FA, FP).

Anotai Suklom, Tosaphol Saetung Keetapithchayakul, Azman Abdul Rahim and Koraon Wongkamhaeng. 2022. Two New Species of the Genus Floresorchestia (Crustacea, Amphipoda, Talitridae) from Amphawa Estuary, Samut Songkhram Province, Thailand. Zoosystematics and Evolution. 98(2): 285-303.  DOI:  10.3897/zse.98.83749

[Crustacea • 2022] Thailandorchestia rhizophila • A New Genus and Species of Driftwood Hopper (Amphipoda: Protorchestiidae) from Thailand

Thailandorchestia rhizophila

 Wongkamhaeng, Dumrongrojwattana, Sumitrakij & Saetung Keetapithchayakul, 2022

 

DOI: 10.3897/zookeys.1099.82949

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Abstract

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., Thailandorchestia rhizophila sp. nov., is described herein, and an updated key to the genera of the family Protorchestiidae is provided.

Keywords: Description, Ko Kut District, marsh hopper, Talitroidea, Thailandorchestia gen. nov.

Thailandorchestia rhizophila sp. nov.

 a holotype, male, 8.04 mm, THNHM-Iv- 18760

b allotype, female, 7.80 mm, THNHM-IV- 18961

c rotting mangrove log, habitat of Thailandorchestia rhizophila sp. nov. 

Thailandorchestia rhizophila sp. nov. holotype, male, 8.04 mm, THNHM-Iv- 18760.

Scale bars: 1 mm.

Systematics

Order Amphipoda Latreille, 1816

Suborder Senticaudata Lowry & Myers, 2013

Family Protorchestiidae Myers & Lowry, 2020

Genus Thailandorchestia gen. nov.

Diagnosis: Protorchestiidae with maxilliped palp article 2 distomedial lobe absent. Mandible left lacinia mobilis 4-dentate. Gnathopod 2 coxal gill simple. Pereopod 4 carpus significantly shorter than carpus of pereopod 3. Pereopods 6–7 sexually dimorphic (male merus and carpus incrassate). Pereopod 7 posterodistal lobe absent. Uropod 1 peduncle distolateral robust setae present, very large (1/3–1/2 length of outer ramus); inner ramus linear, not modified; outer ramus with marginal robust setae. Uropod 2 outer ramus without marginal robust setae. Uropod 3 peduncle with 2 robust setae; ramus shorter than peduncle, linear (narrowing). Telson apically incised, with 2 robust setae per lobe.

Etymology: The generic name, Thailandorchestia gen. nov., is derived from “Thailand” in combination with the Orchestia stem.

Type locality: Mangrove forest near Ban Ao Prao Beach (11°35'40.2"N, 102°33'52.6"E), Trat Province, Thailand.

Ecological type: Driftwood hoppers (virtually confined to rotting driftwood where they live in galleries, consuming rotting driftwood and reproducing with relatively small broods).

 Thailandorchestia rhizophila sp. nov. 

Diagnosis: As for the genus unless otherwise stated. Antenna 1 long, reaching from midpoint to end of article 5 of antenna 2 peduncle. Eye medium (1/5–1/3 of head length). Gnathopod 1 not sexually dimorphic, palm transverse, dactylus shorter than palm. Gnathopod 2 sexually dimorphic (male subchelate, female mitten-shaped). Pleopod 1 outer ramus subequal in length to peduncle. Pleopod 3 outer ramus longer than peduncle.

Ecology: Driftwood hoppers, living inside rotten logs and mangrove roots in the softest part under the bark. The mangrove forest is located near a small creek 50 meters from the beach. The sediment in the forest is muddy sand mixed with leaf litter.

Etymology: The specific epithet refers to the habitat of this amphipod, which is also found inside mangrove roots.

Habitat: Mangrove wood, inside roots and rotting logs.

Distribution: Thailand, Ko Kut District, Inner Gulf of Thailand.

Koraon Wongkamhaeng, Pongrat Dumrongrojwattana, Ratchaneewarn Sumitrakij and Tosaphol Saetung Keetapithchayakul. 2022. Thailandorchestia rhizophila sp. nov., A New Genus and Species of Driftwood Hopper (Crustacea, Amphipoda, Protorchestiidae) from Thailand. ZooKeys. 1099: 139-153.  DOI: 10.3897/zookeys.1099.82949

 facebook.com/KoraonWongkamhaeng/posts/3162070914120965

[Mollusca • 2021] Orbitestella amphaengensis • A New Microgastropod Species (Gastropoda: Heterobranchia: Orbitestellidae) from Bangkok Clay of Samut Sakorn Province, Thailand

 

Orbitestella amphaengensis  

Ketwetsuriya & Dumrongrojwattana, 2021

 RAFFLES BULLETIN OF ZOOLOGY. 69: 

Abstract

 A new species of microgastropod, Orbitestella amphaengensis, is described from Holocene Bangkok clay, where a whale’s skeleton (3,380 ± 30 years old) was found, in Samut Sakorn Province, Central Thailand. This new orbitestellid species is characterised by the presence of prominent keels, characteristics of nodules, spiral series, and numerous axial ribs. The new species is the oldest microgastropod of this family hitherto reported in Thailand and is also the first record of the genus Orbitestella. The presence of this marine microgastropod indicates that the depositional environment was shallow marine deposits. 

Key words. Gastropod, new species, taxonomy, Holocene, diversity

Superorder Heterobranchia Gray, 1840

Family Orbitestellidae Iredale, 1917

Orbitestella Iredale, 1917

Type species. Cyclostrema bastowi Gatliff, 1906.

Diagnosis. Shell thin, pellucid, discoidal, dextral, of few whorls and of peculiar sculpture: widely umbilicate; columella vertical; aperture never varied, irregular in shape, edges thin.

Holotype of Orbitestella amphaengensis, new species (ESKU-2021-I-001).
A, apical view; B, early whorl; C, front view; D, protoconch; E, umbilical view; F, close-up of umbilical view.

  

Orbitestella amphaengensis, new species

Diagnosis. Shell thin, pellucid, discoidal, dextral, of few whorls and of peculiar sculpture: widely umbilicate; columella vertical; aperture never varied, irregular in shape, edges thin.

 

Etymology. After Amphaeng Sub-district, where the studied gastropod material was found.

 

 

Chatchalerm Ketwetsuriya and Pongrat Dumrongrojwattana. 2021. A New Microgastropod Species, Orbitestella amphaengensis, (Gastropoda: Heterobranchia: Orbitestellidae) from Bangkok Clay of Samut Sakorn Province, Thailand. RAFFLES BULLETIN OF ZOOLOGY. 69: 304–308