New Ukrainian records of Branchiobdella parasita (Annelida: Clitellata: Branchiobdellida) from the Danube basin

Abstract

This research deals with the first substantiated Ukrainian records of Branchiobdella parasita (Braun, 1805) from the Danube basin including the Danube Delta and a tributary of the Tisza in Transcarpathia. The localities can be considered as the eastern border of the species range. Four sites (Katlabukh Lake, Kislitsa – Danube, a channel in the Danube Delta - at Vilkovo - and Tereblya river – from Transcarpathia) were surveyed within summer seasons of 2008 - 2009. Hosts included the crayfish species Astacus leptodactylus (Eschscholtz, 1823) and Astacus astacus (Linnaeus, 1758). Information on morphological characters of Branchiobdella parasita including its cocoons is given. Details of host-parasite relationships of the crayfish and the branchiobdellidan are presented. Branchiobdella parasita prefers eyes and maxillipeds of the hosts. It lays cocoons mainly on the lateral cephalotorax. The pattern of cocoon localization is the same in different crayfish species from all studied localities. Infection rates for the adult worms and their cocoons are provided. The percentage (prevalence) of crayfishes infested with adult Branchiobdella parasita reached 100% in two sites (one site from the Danube Delta and in the site from Transcarpathia), meanwhile percentage of crayfishes infested with cocoons of Branchiobdella parasita reached 90% in one site (at Tereblya river from Transcarpathia).

Keywords

• Branchiobdellida
• Branchiobdella parasita
• Danube
• Ukraine
• crayfish