Dactylogyrus wuhuensis Lee, 1960

Nitta, Masato & Nagasawa, Kazuya, 2020, Alien Gill Parasites of the Silver Carp Hypophthalmichthys molitrix (Cypriniformes: Cyprinidae) in Tochigi Prefecture, Central Japan, Species Diversity 25 (1), pp. 61-73 : 66

Dactylogyrus wuhuensis Lee, 1960

[New Japanese name: Buko-yubigata-mushi] ( Fig. 5 )

Dactylogyrus wuhuensis Lee, 1960: 33–36 , figs A, B; Lee 1963: 76; Yukhimenko 1972: 155; Anonymous 1973a: 138, pl. 77, figs 153–154; Musselius 1973: 20, 22, fig. 6ge; Gvozdev and Agapova 1977: 109; Anonymous 1978: 52–53; Chen 1981: 116; Ji et al. 1982: 22; Gussev 1985: 125–126, fig. 161; Huang 1986: 15; Wu and Wang 1991: 18, 102–103, fig. 90; Long 2000: 94–95, fig. 41; Xia et al. 2000: 152; Urazbaev and Kurbanova 2006: 537; Ký and T ề 2007: 136, 139, fig. 116; Gussev et al. 2010: 189–190, 192, fig. 217; Davydov et al. 2012: 141; Zhang 2012: 123.

Dactylogyrus chenshuchenae Gussev in Bykhovskaya-Pavlovskaya et al., 1962: 294–296 , fig. 685; Babayev 1964: 51; Osmanov and Yusupov 1967: 212; Musselius 1969: 238; Osmanov 1971: 107; Hoffman and Schubert 1984: 238; Gibson et al. 1996: 11.

Material examined. One specimen fixed in modified picrate glycerin (NSMT-Pl 6395).

Description. Male copulatory organ ( Fig. 5L ) screlotized, consisting of penis and accessory piece, composition of male copulatory organ of our specimen damaged during preparation. Penis long, length 138. Accessory piece ( Fig. 5L ) rodshaped with bifurcated base and widened tip, length 60. Vagina unsclerotized.

Dorsal anchor ( Fig. 5A ) total length 40; length to notch 35; outer root length 5, inner root length 9, point length 1. Dorsal bar ( Fig. 5B ) bow-shaped, total length 22, total width 6, median width 3. Ventral bar ( Fig. 5C ) broadly M-shaped, total length 35, total width 5, median width 3. Marginal hooks 7 pairs; hook length: pair I ( Fig. 5D ) 29; pair II ( Fig. 5E ) 30; pair III ( Fig. 5F ) 30; pair IV ( Fig. 5G ) 30; pair V ( Fig. 5H ), 27, pair VI ( Fig. 5I ) 29; pair VII ( Fig. 5J ) 32. Pair of needles ( Fig. 5K ) length 11.

Host. Silver carp Hypophthalmichthys molitrix ( Cypriniformes : Cyprinidae )

Site of infection. Gill filaments.

Remarks. This species was originally described by Lee (1960) from the gills, oral cavity, and nasal cavity of H. molitrix in Wuhu , Anhui Province, China. Subsequently, it was reported from the same host in Hubei, Fujian, and Zhejiang provinces, China ( Anonymous 1973a; Huang 1986; Wu and Wang 1991) and Far-East Russia ( Yukhimenko 1972; Musselius 1973). Dactylogyrus chenshuchenae Gussev in Bykhovskaya-Pavlovskaya et al., 1962 described from the gill filaments of the same host in the Liao River, Liaoning Province, China, has been synonymized with D. wuhuensis ( Anonymous 1973a) . The haptoral structures and the accessory piece of the specimen examined in this study conform to those of Lee (1960), Wu and Wang (1991), Long (2000), and Gussev et al. (2010).

The present collection represents the first record of D. wuhuensis from Japan. This monogenean has been reported as an alien species parasitic on H. molitrix from Turkmenistan ( Babayev 1964; Osmanov 1971), the Amu Darya River ( Osmanov and Yusupov 1967), the European region of Russia ( Musselius 1969), Kazakhstan ( Gvozdev and Agapova 1977), the Aral Sea ( Urazbaev and Kurbanova 2006), and Vietnam (Ký and T ề 2007).

Japanese name. In the new Japanese name, “buko” means Wuhu, the type locality of D. wuhuensis, in Japanese , and “yubigata-mushi” means the genus Dactylogyrus .

Figures

Fig. 5. Dactylogyrus wuhuensis Lee, 1960. NSMT-Pl 6395. A, dorsal anchors; B, dorsal bar; C, ventral bar; D, marginal hook of pair I; E, marginal hook of pair II; F, marginal hook of pair III; G, marginal hook of pair IV; H, marginal hook of pair V; I, marginal hook of pair VI; J, marginal hook of pair VII; K, needle; L, male copulatory organ. Scale bars: 10µm. Abbreviations: ap, accessory piece; p, penis.