Dr. Fűköh Levente szerk.: Malakológiai Tájékoztató 13. (Eger, 1994.)

MIENIS, H. K.-ORTAL, R.: Prédation on Limacius flavus by Haemopis sanguisuga in the Middle East

Prédation on Limacus flavus by Haemopis sanguisuga in the Middle East H. K. Mienis-R. Ortal Abstract: A first case of prédation on the terrestrial slug Limacus flavus by the freshwater leech Haemopis sanguisuga is reported from Ein Jawiza, Golan Heights. Key words: Annelida, Hirudinea, Haemopis sanguisuga, prédation, Mollusca, Gastropoda pulmonata, Limacus flavus, Middle East. During hydrobiological fieldwork in the spring of Ein, Jawiza, Golan Heights, on 11 June 1987, an interesting case of prédation on a slug by a large leech was recorded. A large boulder laying partly in the water of the spring turned out to possess a cavity at the underside filled with air. This hole contained three specimens of the Yellow slug Limacus flavus (Linnaeus, 1758), Fam. Limacidae, with a length of respectively 11.3, 10.5 and 9.7 cm. In addition to the slugs there was even a larger specimen of an aquatic leech Haemopis sanguisuga Linnaeus, 1758, Fam. Hirudinidae, with a length of 12.1 cm. The latter was seen to feed on one of the slugs. It had bitten a large hole at the dorsal side of the slug through which it was feeding on the internal organs. In the laboratory the leech attacked almost immediately one of the other slugs when the were put together in a glass jar. It started the feeding action again by tearing a large hole in the dorsum of the slug. According to Dresscher, Th. G. N.-Higler, L. W. G. (1982) this ferocious leech is know to feed on a large variety of invertebrates and vertebrates including terrestrial gastropods. In the literature we came across cases of prédation on the following species: Amber snails of the family Succineidae (Frömming, 1955), the Common Garden snail Cepaea nemoralis (Linnaeus, 1758) (Frömming, 1954) and even adult specimens of the Roman snail Helix pomatia (Linnaeus, 1758) (Frömming, 1927). In the case it attacks species of the Helicidae (Cepaea and Helix) it has even to leave the water in order to hunt for a prey on the shore. Since slugs are known to enter water often on a voluntary base (von Gelei, J. 1928; Künkéi, K. 1930; Soós, L. 1927), Limacus flavus used the underwater cavity most probably as a place to aestivate during the long hot and dry summer. However, by acting so it created at the same time an excellent oppurtunity for a hungry leech to catch an easy prey. According to our information this is the first time that Limacus flavus is recorded as a food item of Haemopis sanguisuga. References Dresscher, Th. G. N., & Higler, L. W. G., (1982): De Nederlandse bloedzuigers Hirudinea. Wetenschap. Mededel. K. N. N. V., 154: 1-64. Frömming, E., (1927): Weinbergschnecke und Pferdeegel. Wschr. Aq.-Terr. Kunde, 24: 719. Frömming, E., (1954): Biologie der mitteleuropäischen Landgastropoden. 404 pp. Duncker & Humblot, Berlin. Frömming, E., (1955): Die ükologische Beziehungen zwischen unseren Landlungenschnecken und den Würmern. Zool. Anz., 154 (9-10): 253-259.