Gyrodactylus gymnodiptychi, Zhang & Hao & Arken & Rong & Tian & Kadir & Yue, 2023

Zhang, Wen-Run, Hao, Cui-Lan, Arken, Kadirden, Rong, Meng-Jie, Tian, Sheng-Li, Kadir, Munira & Yue, Cheng, 2023, New species of Gyrodactylus von Nordmann, 1832 (Monogenoidea: Gyrodactylidae) from Gymnodiptychus dybowskii (Kessler, 1874) (Schizothoracinae) in the Kunes River (Yili River basin), China, International Journal for Parasitology: Parasites and Wildlife 22, pp. 136-145 : 139-140

publication ID	https://doi.org/ 10.1016/j.ijppaw.2023.10.002
DOI	https://doi.org/10.5281/zenodo.14055920
persistent identifier	https://treatment.plazi.org/id/580F7170-1F72-EB00-FCBF-0EECFEAAFA7D
treatment provided by	Felipe
scientific name	Gyrodactylus gymnodiptychi
status	sp. nov.

Treatment

Gyrodactylus gymnodiptychi View in CoL n. sp.

Type host: Gymnodiptychus dybowskii Kessler, 1874 .

Type locality: Kunes River , Xinjiang Uygur Autonomous Region, China (82 ◦ 34′49.61″ N; 84 ◦ 44′30.41″ E) GoogleMaps .

Site of infection: gills and fins.

Types material: The Holotypes XJLCC20191101 GoogleMaps and the Paratypes XJLCC20191102-05 are deposited in the museum of Parasitology at the Xinjiang Agricultural University. GoogleMaps

Genetic material: The ITS1-5.8S-ITS2 rDNA sequence was deposited in the GenBank (Accession numbers MH445967 and MH445968).

Etymology: The species was named by referring to the genus of host Gymnodiptychus dybowskii from which it parasitized.

Zoo bank: LSID urn:lsid:zoobank.org:pub:34E792F3-9ED8-45C3-A673-FC5C44577BAC .

3.2. Morphology

Based on 28 specimens. Body "gourd-like" shape, fusiform, a depression in the middle of body, total body length 368.0 (223.3–608.0) long, 80 (62.0–136.5) wide. Pharynx bulb 21.1 (13.8–29.7) long, 19.7 (13.6–28.2) wide ( Fig. 1A View Fig and Table 2 View Table 2 ). The cecum was posterior to the anterior edge of the testes ( Fig. 1A View Fig ). MCO 12.3 (8.0–19.9) long, 8.5 (6.9–10.2) wide, armed with one central spine, two large spines and three small spines, posterior to pharyngeal bulb ( Fig. 1B View Fig & 2A View Fig ). Hamuli 61.6 (57.5–73.7) long, shafts 52.3 (44.9–55.9) long, points 28.2 (18.8–39.0) long, slim; proximal shaft 8.4 (7.9–11.2) wide, curved. Aperture distance 19.1 (18.8–23.8) long, hamulus aperture angle 31.7 ◦ (26.9 ◦ –33.5 ◦), hamulus root 22.4 (18.8–25.8) long, inward and curved ( Fig. 1C View Fig & 2B View Fig ). Dorsal bar 29.2 (21.7–38.6) long, 2.2 (1.6–3.3) wide, the middle flat, straight, with a hollow at each end ( Fig. 1E and F View Fig and 2C & D View Fig ). Ventral bar 40.7 (35.8–53.1) long, 8.0 (6.5–10.9) wide, ventral bar processes 12.1 (7.8–14.3) long, ovoid; ventral bar membrane 19.9 (15.9–22.3) long ( Fig. 1G View Fig & 2E View Fig ). Marginal hook 38 (30.4–45.6) long, hook shaft 32.6 (24.1–37.9) long, rounded bottom; marginal hook sickle 8.7 (6.4–10.6) long, curved, tilted forward; sickle point 5.2 (3.6–5.7) wide, sickle distal 3.7 (2.7–5.0) wide. Marginal hook toe 2.23 (2.1–2.8) long, marginal hook aperture 7.1 (7.0–8.5) long, hook instep 1.0 (0.9–1.3) high, and filament loop 12.2 (12.0–16.1) long ( Fig. 1H View Fig & 2F View Fig ).

3.3. Remarks

To understand the association of G. gymnodiptychi n. sp. with known members of Gyrodactylus , we compared the morphological features of G. gymnodiptychi n. sp. with Gyrodactylus aksuensis Ergens and Karabekova (1980) ; Gyrodactylus tokobaevi Ergens and Karabekova (1980) ; and Gyrodactylus montanus Bychowsky, 1957 ; Ergens and Karabekova (1980); Gusev, 1985). As depicted in Fig. 3 View Fig , compared with G. aksuensis , the dorsal bar of G. gymnodiptychi n. sp. was raised at both ends with a hollow, but G. aksuensis was lanker and narrower than G. gymnodiptychi n. sp. ( Fig. 3A and B View Fig ). Gyrodactylus gymnodiptychi n. sp. exhibited similar ventral bar morphology to the G. tokobaevi ( Fig. 3A and C View Fig ). In both species, their ventral bar processes were prominent, but hamulus roots of G. gymnodiptychi n. sp. were curved inward. In addition, the dorsal bar of G. gymnodiptychi n. sp. had a straight center and a projection with a hollow at both ends, but the G. tokobaevi only had prominent ends without hollow. Additionally, the MCO of G. gymnodiptychi n. sp. had three spines fewer than G. tokobaevi ( Fig. 3A and C View Fig ). Gyrodactylus gymnodiptychi n. sp. exhibits similar dorsal bar morphology to the G. montanus . In both species, their dorsal bars had a hollow at both ends of the projection, but the hamulus root of G. gymnodiptychi n. sp. was curved inward and stouter than G. montanus . In addition, the ventral bar processes of G. gymnodiptychi n. sp. were more prominent than G. montanus ( Fig. 3A and D View Fig ). The results clearly revealed identifiable morphological differences between G. gymnodiptychi n. sp. and other Gyrodactylus members. In addition, G. gymnodiptychi n. sp. was the only one showing a hollow dorsal bar and curved hamulus root that were distinct from the other eleven species, carrying non-hollow dorsal bars and straight hamuli roots, of gyrodactylid isolated from the fish subfamily Schizothoracinae .