Bivaginogyrus obscurus (Monogenea: Dactylogyridae), a Gill Parasite of Two Cyprinids Pseudorasbora pumila pumila and Pseudorasbora parva, New to Japan

Abstract

The dactylogyrid monogenean Bivaginogyrus obscurus (Gussev, 1955) is redescribed from the gills of two cyprinids, Pseudorasbora pumila pumila Miyadi, 1930 in Nagano Prefecture and P. parva (Temminck and Schlegel, 1846) in Ibaraki Prefecture. These are the first records of this parasite in Japan. Pseudorasbora p. pumila, which is endemic to central Japan, represents a new host record for B. obscurus. This monogenean is the first helminth and the second parasite discovered from wild P. p. pumila.

New Geographical Records of Three Gill Monogeneans (Platyhelminthes) Parasitic on <i>Pseudorasbora parva</i> (Cypriniformes: Cyprinidae) in Japan

“…Remarks. In Japan this monogenean was first described from Pseudorasbora parva and P. pumila Miyadi, 1930 in Lake Kasumigaura, Ibaraki Prefecture and in ponds of Shinonoi, Nagano Prefecture, respectively by Nitta and Nagasawa (2014). The specimens from Nara and Okayama prefectures correspond well with those from Lake Kasumigaura and ponds of Shinonoi.…”

“…Two of the three monogeneans found in this study, Dactylogyrus squameus and Ancyrocephalus pseudorasborae, were collected from Pseudorasbora parva in the native habitats of this fish in Japan. Thus, as with Bivaginogyrus obscurus (Nitta and Nagasawa 2014), they are considered to be native to Japan. Recently, P. parva has been recorded in Hokkaidō, the Tōhoku District, and Okinawa Prefecture as a domestic alien freshwater fish (Matsuzawa and Senou 2008), and it has also been suggested that some individuals of the species were introduced from the Eurasian continent into several rivers in Japan (Watanabe et al 2000;Yoshigou 2013).…”

“…The latter two species are endemic to Japan and have been designated as critical endangered species by the Ministry of the Environment of Japan (Sugiyama 2015;Kawamura 2015). To date, Bivaginogyrus obscurus has been reported from P. pumila (Nitta and Nagasawa 2014), but nothing is known about the monogenean fauna of P. pugnax. More study is needed on the monogeneans of these fishes because host-specific parasites of endangered hosts are sometimes threatened with co-extinction (Windsor 1990;Stork 1993;Barus et al 1997).…”

“…The fish has spread into Europe as an invasive species along with two dactylogyrid monogeneans, Dactylogyrus squameus Gussev, 1955 and Bivaginogyrus obscurus (Gussev, 1955) (Ondračkova et al 2004;Galli et al 2007;Gozlan et al 2010;Anonymous 2012). The monogenean fauna of this fish is poorly known in Japan, where only B. obscurus has been reported from Ibaraki Prefecture (Nitta and Nagasawa 2014). In this paper, we examined Pseudorasbora parva collected from natural habitats in Japan and report Dactylogyrus squameus and Ancyrocephalus pseudorasborae Achmerow, 1952 as new country records and Bivaginogyrus obscurus as new prefectural records.…”

An Alien Monogenean, Ligictaluridus pricei (Platyhelminthes: Ancyrocephalidae), Parasitic on the Channel Catfish Ictalurus punctatus (Actinopterygii: Siluriformes: Ictaluridae) in Japan

“…nebulosus (as I. nebulosus), I. punctatus, N. gyrinus, N. flavus Nepszy (1988) Mexico Ictalurus cf. pricei Rosas-Valdez and León (2005), León et al (2010), Salgado-Maldonado and Quiroz-Martínez 2013Schlegel, 1846) (Cypriniformes: Cyprinidae), respectively (Kamegai 1968, Nitta andNagasawa 2014). Infection by alien monogeneans sometimes poses a high risk for native fish resources (Petrushevski and Shulman 1970;Johnsen and Jensen 1986;Yoshinaga et al 2001;Ogawa 2005Ogawa , 2010Taraschewski 2006), so it is necessary to clarify and monitor the monogenean fauna of this lake.…”