Fish

The water bodies of the Žemaitija National Park host 33 species of the bony fish (Osteichthyans) class, both native and introduced in Lithuania, and one representative of the jawless fish (Cephalaspidomorphs) – brook lamprey (Lampetra planeri). Two of the former – weatherfish (Misgurnus fossilis) and a sub-species of Coregonus lavaretus (Coregonus lavaretus holsatus Thienemann nat. platelensis) which is endemic to lake Palteliai, are listed in the Lithuanian Red Book, five are protected species of European Community importance. The most abundant and widespread in the waters of the national park are roach (Rutilus rutilus), common rudd (Scardinius erythrophthalmus), common perch (Perca fluviatilis), pikes (Esox spp.), tench (Tinca tinca), bream (Abramis brama), crucian carp (Carassius carassius) and other species. Cold-loving salmon family fish swim in Lake Plateliai – Coregonus lavaretus and European cisco (Coregonus albula). In order to restore the european crisco populations, Lake Plateliai donor population has been used to release this species into lakes Akmena, Asveja, Spindžius, Verinejus and other lakes. In accordance with the plan for the introduction of fish and crayfish into public water bodies, the lakes are regularly stocked with native, mainly predatory fish species.

In clean and flowing streams are breeding grounds for spined loach (Cobitis taenia), European bullhead (Cottus gobio), stone loach (Barbatula barbatula), amur bitterling (Rhodeus sericeus) and brook lamprey. In order to increase the population of weatherfish (Misgurnus fossilis) in the national park, these fish were additionally introduced into the oxbow lake of the Uošna stream. This was implemented in accordance with the action plan for weatherfish protection prepared by the Ministry of the Environment.