Common Freshwater Fish Nematodes In Latvia Author Kirjusina, Muza Corresponding author: Muza Kirjusina. Institute of Life Sciences and Technology. Daugavpils University, Parādes Str. 1 a, Daugavpils, LV- 5401, Latvia, E-mail: muza. kirjusina @ du. lv Author Paidere, Jana Author Rubenina, Ilze Author Kecko, Sanita Author Bricis, Reinis Author Mežaraupe, Ligita Author Gavarane, Inese text Acta Biologica Universitatis Daugavpiliensis 2023 2023-12-30 23 2 189 206 https://du.lv/en/research/institutes/institute-of-life-sciences-and-technologies/issued-journal/acta-biologica-universitatis-daugavpiliensis/acta-biologica-universitatis-daugavpiliensis-archives/acta-biologica-universitatis-daugavpiliensis-volume-23-no-2-2023/common-freshwater-fish-nematodes-in-latvia-2/ journal article 10.59893/abud.23(2).006 1407-8953 Philometra ovata (Zeder, 1803) Skrjabin , 1923 196 For the first time in Latvia this freshwater nematode has been reported by S.S. Shulman (1949) . In body cavity (females) and under serosa of swimbladder (males) in bream and 7.3% ruffe nematoda was detected ( Shulman 1949 , Vismanis & Popov 1990 ). This philometrid is a common parasite of the body cavity of many species of cyprinids in Europe and Asia ( Anderson 2000 ). Gravid and subgravid females are found in the body cavity, while juveniles, males and unfertilized females occur under the serosa of the posterior part of the swimbladder. The life cycle is similar to P. abdominalis ( Molnar 1966 , Moravec 1980b ). Intermediate hosts are cyclops Cyclops strenuus , Macrocyclops albidus . In Latvian water bodies, Cyclops strenuus is common and widely distributed ( Deimantoviča et al. 2011 , Dimante- Deimantoviča 2012 ). Overall, it can be recorded from a variety of water bodies (lakes, ponds, fish ponds, rivers, estuaries, floodplain lakes and reservoirs). Macrocyclops is one of the most common genera from Eucyclopinae in Latvian freshwaters ( Deimantoviča et al. 2011 ). Macrocyclops albidus is widespread in Latvian freshwaters (Dimante-Deimantoviča 2012), it can be recorded from a variety of water bodies such as lakes, rivers, ponds (Nagļi fish ponds) ( Paidere 2019 ), floodplain lakes (floodplain Lake Dvietes) ( Paidere 2013 ).