Camallanus Railliet et Henry, 1915

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 23 (2), pp. 189-206 : 194-195

Genus Camallanus Railliet et Henry, 1915

Camallanus (Camallanus) lacustris (Zoega, 1776) Railliet and Henry, 1915

For the first time in Latvia, this freshwater nematode has been reported by S. S. Shulman (1949). In the intestine and pyloric caeca of perch, zander, pike, ruffe, eel and turbot C. lacustris was found. The prevalence of infection was higher in rivers (75.0-100.0%) and in lakes – 33.7-80.0%. The parasite was more common in perch, the intensity reached 100.0% and the intensity was up to 41 specimens of the parasite per fish ( Kirjusina & Vismanis 2004). The first intermediate hosts are various copepods ( Megacyclops , Macrocyclops , Mesocyclops , Cyclops, Acanthoclops , Eucyclops ). Megacyclops viridis is also common and widely distributed in Latvian freshwaters ( Deimantoviča et al. 2011, Dimante-Deimantoviča 2012). In Latvian freshwater bodies, the species is recorded from lakes (e.g., Riču, Sventes, Drīdzis, Geraņimovas Ilzas ( Vezhnovets & Škute 2012, Brakovska et al. 2020), Jazinkas, Lejas, Nirzas, Rāznas, Ārdavs, Sīvers, Alauksts, Bešons, Dagdas, Dubuļu, Lielais Gusena, Laucesas, Usmas, Puzes (Unpublished zooplankton data of Latvian priority salmonoid water lakes 2009, 2010), Saukas ( Paidere 2020). Overall, it can be recorded from a variety of water bodies (ponds, fish ponds, rivers, floodplain lakes, for example, floodplain Lake Dvietes ( Paidere 2013). The definitive hosts are mainly fish of the Percidae family. Many fish species

Common freshwater fish nematodes in Latvia

( Cobitidae , Cyprinidae , Esocidae , Salmonidae ) can act as paratenic hosts (Campana- Rouget 1961, Moravec 1971а, Moravec 1971b, Moravec 1994).

Camallanus (Camallanus) truncatus (Rudolphi, 1814) Törnquist, 1931

For the first time in Latvia, this freshwater nematode has been reported by S.S. Shulman (1949). This nematode was found rarely and in single copies in the intestine of six species of fish: pike, perch, zander, catfish and turbot ( Kirjusina & Vismanis 2004, 2007). The first intermediate hosts are copepods ( Mesocyclops , Megacyclops , Macrocyclops , Cyclops ). In Latvian water bodies, Cyclops strenuus is common and widely distributed ( Deimantoviča et al. 2011, Dimante-Deimantoviča 2012). The distribution of Megacyclops in Latvia is described in the section about C. lacustris parasite. Fish become infected by feeding copepods infected with larvae. Juveniles of various cyprinids ( Leuciscus , Abramis ) probably serve as paratenic hosts. Although the principal hosts of Camallanus truncatus seem to be fishes of the genus Stizostedion , it also occurs in other percids and in many fish species of different families (Moravec 1994).