Philometra abdominalis Nybelin, 1928

Kirjusina, Muza, Paidere, Jana, Rubenina, Ilze, Kecko, Sanita, Bricis, Reinis, Mežaraupe, Ligita & Gavarane, Inese, 2023, Common Freshwater Fish Nematodes In Latvia, Acta Biologica Universitatis Daugavpiliensis (Sao Paulo, Brazil) 23 (2), pp. 189-206 : 195-196

Philometra abdominalis Nybelin, 1928

In body cavity, under serosa of swimbladder wall of a roach from a lake and river nematode was found for the first time in Latvia ( Vismanis & Popov 1990). Gravid and subgravid females are found in the body cavity, while juveniles, males and unfertilized females are located under the serosa of the

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Muza Kirjusina , Jana Paidere, Ilze Rubenina, Sanita Kecko, Reinis Bricis, Ligita Mežaraupe, Inese Gavarane posterior portion of the swimbladder wall ( Anderson 2000). The life cycle is one year. The first intermediate hosts are copepods ( Macrocyclops , Megacyclops , Diacyclops ), which become infected by eating larvae that emerge either from the body of a female worm that has left the fish, or that has entered the external environment with the reproductive products of fish. Fish become infected by feeding on infected crustaceans ( Molnar 1967, Moravec 1977, Moravec 1994). The distribution of Megacyclops in Latvia is mentioned in the section about C. lacustris and the distribution of Macrocyclops is described in the section about P. ovata parasite. According to K. Molnar (1966), only gudgeons and minnows are obligate definitive hosts, where females reach sexual maturity.

Philometra obturans (Prenant, 1886) Skrjabin, Shikhobalova, Sobolev, Paramonov & Sudarikov, 1954

For the first time in Latvia this freshwater nematode has been reported by S.S. Shulman (1949) as syn. Filaria obturans Prenant, 1886 . Rare nematode was found in single specimens in gill arteries, ventral aorta of pike from lakes ( Reinsone 1955 a, Reinsone 1955b, Reinsone 1959, Kirjusina & Vismanis 2004). Adult mature females are located in the gill blood vessels, males and young females are in the wall of the swim bladder, in the mesentery and in the vitreous body of the eyes of the pike. The first intermediate hosts are copepods ( Cyclops , Eucyclops , Acanthocyclops , Macrocyclops , Megacyclops ). In Latvian water bodies, Cyclops strenuus is common and widely distributed ( Deimantoviča et al. 2011, Dimante-Deimantoviča 2012). Megacyclops distribution is described in the section about C. lacustris parasite. The definitive host (pike) becomes infected by feeding on infected copepods, or by feeding on planktivorous fish that serve as paratenic hosts ( Molnar 1976, Moravec 1978, Moravec & Dykova 1978, Moravec 1994).