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| Durgella pentata Pholyotha & Panha, sp. nov. Durgella nulla Pholyotha & Panha, sp. nov. in Pholyotha, Sutcharit, Lwin et Somsak, 2024. |
Durgella is a terrestrial semislug genus in the family Helicarionidae and currently comprises nine species recorded from Thailand and Myanmar. Two species, D. concinna and D. rhaphiellus, have been described based only on shell information, while the taxonomy of the remaining seven species is comprehensively treated herein using comparative morphology. Revised species descriptions are given for D. levicula, D. erratica, D. siamensis, and D. libas; D. birmanica (previously placed in the Megaustenia) is moved to this genus; and two species, D. pentata Pholyotha & Panha, sp. nov. and D. nulla Pholyotha & Panha, sp. nov., are described as new to science. Based on our findings, the combination of shell characters including shape, size, aperture, and umbilicus; the number of mantle extensions; and the genitalia, especially the penis, epiphallus, and dart apparatus, can be used to distinguish these nine species. Among these ninerecognised species, only D. nulla Pholyotha & Panha, sp. nov. has no dart apparatus.
Key words: Comparative morphology, Durgellinae, Indochina, Land snail, Systematics, Taxonomic revision
TAXONOMY
Superfamily Helicarionoidea Bourguignat, 1877
Family Helicarionidae Bourguignat, 1877
Subfamily Durgellinae Godwin-Austen, 1888
Genus Durgella Blanford, 1863
Durgella birmanica (Pfeiffer, 1847)
Durgella levicula (Benson, 1859)
Durgella erratica (Godwin-Austen, 1888)
Durgella concinna Blanford & Godwin-Austen,
1908
Durgella rhaphiellus (Martens, 1867)
Durgella siamensis Möllendorff, 1902
Durgella libas Solem, 1966
Durgella pentata Pholyotha & Panha, sp. nov.
Diagnosis: Shell depressedly subglobose, thin,
polished, dark yellow with a creamy tinge, and aperture
roundly lunate, broader than high; animal with five
mantle extensions; genitalia with very short vagina,
small epiphallic caecum, short gametolytic duct, and
very large dart apparatus.
Etymology: The specific name “pentata” is from
the Greek word meaning five, referring to the presence
of five mantle extensions.
Durgella nulla Pholyotha & Panha, sp. nov.
Diagnosis: Shell depressedly subglobose,
membranous, polished, dark yellowish with olive tinge;
animal with two different colours: upper body dark
brown or blackish and from lower body to foot margin
creamy; four mantle extensions; genitalia with very
large penis, short gametolytic duct, and without dart
apparatus.
Etymology: The specific name “nulla” is from the
Latin adjective meaning not any, none, nobody, or no,
and refers to the absence of dart apparatus.
Arthit Pholyotha, Chirasak Sutcharit, Ngwe Lwin and Panha Somsak. 2024. Unveiling the Diversity of the Semislug Gnus Durgella Blanford, 1863 (Eupulmonata: Helicarionidae) from Thailand and Myanmar, with Description of Two New Species. Zool Stud. 63:14. DOI: 10.6620/ZS.2024.63-14.
หอยหางดิ้น สกุล 𝐷𝑢𝑟𝑔𝑒𝑙𝑙𝑎 ชนิดใหม่ของโลก 2 ชนิดจากประเทศไทยและเมียนมาร์ คือ
1. 𝐷𝑢𝑟𝑔𝑒𝑙𝑙𝑎 𝑝𝑒𝑛𝑡𝑎𝑡𝑎 Pholyotha & Panha, 2024
หอยหางดิ้นเชียงดาว ค้นพบที่ อ.เชียงดาว จ.เชียงใหม่
2. 𝐷𝑢𝑟𝑔𝑒𝑙𝑙𝑎 𝑛𝑢𝑙𝑙𝑎 Pholyotha & Panha, 2024
หอยหางดิ้นอีสาน ค้นพบที่ จ.เลยและหนองบังลำภู