Predation in two species of leech under laboratory conditions

Two 60 day experiments on predation behavior of leeches were conducted concurrently. In the first, medicinal leeches, Hirudo orientalis (Utevsky and Trontelj, 2005) were fed to satiation on bovine blood and subsequently transferred into two large opaque plastic containers of equal size but with differing temperatures, 6-7?C and 23-24?C, containing starved Erpobdella octoculata (L.). At the higher temperature E. octoculata rapidly attacked and swallowed juvenile and adult medicinal leeches. This also occurred at the lower temperature but took place more slowly. In the second experiment, under similar physical conditions, starved medicinal leeches and satiated E. octoculata were studied. Starved H. orientalis attached to and sucked ingested blood from juvenile E. octoculata but did not consume them. H. orientalis did not feed on adult E. octoculata. These observations confirm interspecific predation between two families of leeches, Hirudinidae and Erpobdellidae. Numbers and wet mass of prey leeches decreased rapidly at the higher temperature, especially when E. octoculata was the predator. ? 2011 Progress in Biological Sciences. Vol. 1, No. 2, 11-15.