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| Glyptothoa sagara Helna, Aneesh, Kumar & Ohtsuka, 2023 |
Glyptothoa sagara gen. and sp. nov. is described from the host fish Glyptophidium macropus Alcock, 1894 (Ophidiidae), at depths 300 to 650 metres from the southwest coast of India. The mitochondrial cytochrome c oxidase subunit I (COI) gene of the species was sequenced and compared with other closely related branchial cymothoid genera. Both morphological and molecular data corroborate the inclusion of this parasitic isopod as a new genus, and we describe Glyptothoa sagara gen. and sp. nov. The following combinations of characters characterise the genus: cephalon immersed in pereonite 1; dorsum vaulted; all coxae visible in dorsal view; coxae shorter than or as long as pereonites; pereonites 4–7 slightly decrease in width towards one side, slightly asymmetrical, lateral margins slightly constricted, in hunched side; relatively wide pleon, with large lateral gaps between pleonites; antennula narrowly separated by rostrum, slender, shorter than antenna; antenna with 13 articles, buccal cone obscuring antennal bases; brood pouch arising from coxae 1–4, 6; oostegite 1 bilobed; pleopods rami all simple, without proximomedial lamellar lobe, without folds or thickened ridges. The adult life stages, such as females (ovigerous and non-ovigerous), males and transitional stage of the new species are described. The species is currently known only from the type locality and the type host. The ecological remarks of the newly described taxon are also provided. The following species are transferred from Elthusa Schioedte and Meinert, 1884: Glyptothoa myripristae (Bruce, 1990) comb. nov., Glyptothoa propinqua (Richardson, 1904) comb. nov. and Glyptothoa caudata (Schioedte and Meinert, 1884) comb. nov.
Key words: Marine fish parasite, Branchial cavity, Cytochrome c oxidase subunit I, Cymothoidae, New genus, Indian Ocean, Phylogeny
TAXONOMY
Suborder Cymothoida Wägele, 1989
Superfamily Cymothooidea Leach, 1814
Family Cymothoidae Leach, 1814
Genus Glyptothoa gen. nov.
Type species: Glyptothoa sagara sp. nov.; original designation.
Etymology: The new generic name is the abbreviation of the host genus name (Glyptophidium) – “Glypto” combined with the ending – thoa indicating the family affinity. Gender is feminine.
Diagnosis: Ovigerous female (bold = key features): Body dorsally vaulted, two times as long as wide, widest at pereonite 3. Cephalon partially immersed in pereonite 1, anterior margin with acute ventrally directed rostral point. Pereonites 2–7 coxae visible in dorsal view, all coxae shorter than pereonite; pereonites 4–7 slightly asymmetrical, lateral margins slightly constricted, in hunched side. Pereonites 4–7 slightly decrease in width towards one side. Pleon short, c. 15% BL, pleonites all visible, ...
Species included: Glyptothoa sagara sp. nov.;
Glyptothoa propinqua (Richardson, 1904) comb. nov.,
Glyptothoa myripristae (Bruce, 1990) comb. nov., and
Glyptothoa caudata (Schioedte and Meinert, 1884) comb. nov.
Glyptothoa sagara sp. nov.
Etymology: The specific name is derived from the Sanskrit word “sagara”, literally meaning the “gathering together of waters,” i.e., the ocean. Further, it is a reminder of the importance of the ocean for the sustainable development of life underwater and its conservation.
Ameri Kottarathil Helna, Panakkool Thamban Aneesh, Appukuttannair Biju Kumar and Susumu Ohtsuka. 2023. Glyptothoa gen. nov., A Fish Parasitic Deep-Sea Cymothoid (Crustacea: Isopoda) from the Indian Ocean, with Four Species, Including One New Species. Zool Stud. 62:51. DOI: 10.6620/ZS.2023.62-51
