Showing posts with label Author: Lheknim. Show all posts
Showing posts with label Author: Lheknim. Show all posts

Tuesday, May 21, 2024

[Crustacea • 2023] Stoliczia setoiyenica • A New Species of Freshwater Crab (Decapoda: Brachyura: Potamidae) from southern Thailand


 Stoliczia setoiyenica
 Tan, Lheknim & Ng, 2023
 
 
Abstract
A new species of freshwater crab is described from southern Thailand, near the border with Peninsular Malaysia. Species of Stoliczia are characterised by their relatively flat carapace, a third maxilliped exopod that possesses no or a very short flagellum, and a conical male gonopod terminal segment that lacks or only has a very low dorsal fold. Stoliczia setoiyenica, new species, most closely resembles S. perlensis and S. kedahensis from northern Peninsula Malaysia but can be easily distinguished from congeners by differences in carapace and male gonopod morphology. Comparisons to the two known Thai Stoliczia species, S. panhai and S. ekavibhathai, are also provided for completeness.

Crustacea, Satun Province, Isthmus of Kra, Potamoidea, taxonomy



Stoliczia setoiyenica, new species


 Zhi Wan Tan, Vachira Lheknim, and Peter K. L. Ng. 2023. Stoliczia setoiyenica, A New Species of Freshwater Crab from southern Thailand (Crustacea: Decapoda: Brachyura: Potamidae).  Zootaxa. 5360(4); 531-544. DOI: 10.11646/zootaxa.5360.4.4

Tuesday, May 14, 2024

[Crustacea • 2024] Demanietta moror • A New Species of Freshwater Crab (Brachyura: Potamidae) from A Karst Formation in southern Thailand


Abstract
A new species of potamid crab belonging to the genus Demanietta Bott, 1966 is described from a creek draining out of a karst formation associated with the Phuket Mountain Range in southern Thailand. Demanietta moror new species, belongs to a group of Demanietta species that has a relatively inflated and smooth carapace, and a male first gonopod that is weakly bent, appearing more vertically projected. It can be immediately distinguished from all congeners by its carapace, gonopod morphology and unique colour pattern in life.

Keywords: Surat Thani Province; Isthmus of Kra; taxonomy; Potamoidea



Demanietta moror new species


 Zhi Wan Tan, Vachira Lheknim, and Peter K. L. Ng. 2024. A New Species of Freshwater Crab, Demanietta moror, from A Karst Formation in southern Thailand (Brachyura, Potamidae).  Crustaceana. 97(3-4); 307–319. DOI: 10.1163/15685403-bja10362


Résumé: Une nouvelle espèce de crabe Potamidae appartenant au genre Demanietta Bott, 1966, est décrite d’un ruisseau s’écoulant d’une formation karstique associée à la chaîne de montagnes de Phuket, dans le sud de la Thaïlande. Demanietta moror n. sp., appartient à un groupe d’espèces du genre Demanietta qui possède une carapace lisse et relativement bombée, et un premier gonopode mâle faiblement recourbé, apparaissant projeté plus verticalement. Elle se distingue immédiatement de tous ses congénères par sa carapace, la morphologie du gonopode et une couleur unique à l’état vivant.

Thursday, June 1, 2023

[Crustacea • 2023] Demanietta sunthorni • A New Species of Freshwater Crab (Decapoda: Brachyura: Potamidae) from Adang-Rawi Island Group, Andaman Sea, south Thailand


Demanietta sunthorni 
Lheknim, Leelawathanagoon & Ng, 2023

RAFFLES BULLETIN OF ZOOLOGY. 71

Abstract
 A new species of a potamid crab belonging to the genus Demanietta Bott, 1966, is described from Adang Island, Andaman Sea, off Satun, south Thailand. Demanietta sunthorni, new species, belongs to a group of Demanietta species which has a distinct epibranchial tooth, and strong epigastric and postorbital cristae on the carapace. It can be distinguished from all congeners most easily by the form of the male first gonopod which is slender, with the terminal segment sinuous, upcurved and possessing a large dorsal fold. This is the southernmost record of the genus. 

Key words. Satun Province, Tarutao National Park, Isthmus of Kra, Potamoidea, taxonomy, new species


Family Potamidae Ortmann, 1896 
Subfamily Potamiscinae Bott, 1970 sensu Yeo & Ng (2004)

Demanietta sunthorni, new species
Colour in life of holotype male (36.6 × 27.7 mm) (ZRC 2022.0826), Thailand.

Demanietta sunthorni, new species
 ปูน้ำตกเกาะอาดัง

Diagnosis. Carapace subquadrate, width to length ratio 1.26– 1.32; dorsal surface relatively low, not inflated; frontal region with numerous blunt granules (Figs. 2, 3A–D); epigastric cristae clearly demarcated, area with mix of granules and rows of transverse striae; postorbital cristae distinct, sharp, separated from epigastric cristae by distinct gap; postorbital cristae joining epibranchial tooth by uneven granulated ridge; external orbital tooth triangular with outer margin longer than inner margin, clearly separated from epibranchial tooth by small cleft; epibranchial tooth distinct, triangular (Fig. 3B); posterior part of anterolateral region and posterolateral region with distinct transverse striae; subhepatic, suborbital and pterygostomial regions with distinct striae and granules (Fig. 3C); posterior margin of epistome with distinct acutely triangular median tooth (Fig. 3C, D); third maxilliped ischium subrectangular, ...

Etymology. The species is named after the late Assoc. Prof. Sunthorn Sotthibandhu, an eminent entomologist of the Biology Department, Faculty of Science, Prince of Songkla University (PSU). He used to be the head of the Department of Biology, as well as PSU President, and President of Songkhla Rajabhat University. The first author has known Ajarn Sunthorn for nearly 40 years, since he was an undergraduate student in his class. He was the first one who taught the first author the beauty of science and how it works. He has been an excellent colleague and a wonderful collaborator on teaching and science, and the many insightful discussions with him will be missed. After his retirement, he continued with research on the philosophy of science and kept working on this topic to his last day. He will be sorely missed. The specific epithet is derived from his first name, Sunthorn.


Vachira Lheknim, P. Leelawathanagoon and Peter K. L. Ng. 2023. Demanietta sunthorni, A New Species of Freshwater Crab (Crustacea: Decapoda: Brachyura: Potamidae) from Adang-Rawi Island Group, Andaman Sea, south Thailand. RAFFLES BULLETIN OF ZOOLOGY. 71; 377–386.  

Saturday, February 4, 2017

[Crustacea • 2016] Terrapotamon longitarsus • A New Species of Long-legged Terrestrial Terrapotamon Ng, 1986 (Brachyura: Potamidae) from Limestone Formations in Satun, southern Thailand


Terrapotamon longitarsus  
Lheknim & Ng, 2016


Abstract

A new species of terrestrial potamid crab, Terrapotamon longitarsus, is described from limestone hills in Satun Province in southern Thailand. It is easily distinguished from other Terrapotamon species by its conspicuously long ambulatory legs (all congeners have proportionately short legs), relatively smooth dorsal surface of carapace, transversely narrow male thoracic sternites 1–4, and a characteristically structured male first gonopod.

Keywords: Crustacea, comparative morphology, freshwater crab, Indochina, new species, Southeast Asia, systematics



photos: Ronnaphon Engchuan




Vachira Lheknim and Peter K.L. Ng. 2016. A New Species of Long-legged Terrestrial Terrapotamon Ng, 1986 (Crustacea: Brachyura: Potamidae) from Limestone Formations in Satun, southern Thailand.
Zootaxa. 4200(1); 143–152. DOI: 10.11646/zootaxa.4200.1.6