Dr. Fűköh Levente szerk.: Malakológiai Tájékoztató 16. (Eger, 1997.)

DÁVID, Á.: Predation by Muricid Gastropods on Late-Oligocene (Egerian) Molluscs Collected from Wind Brickyard, Eger, Hungary

molluscan species were epibenthonic. In the examined material the occurrence of depositfeeders, suspensionfeeders and herbivores can be observed. Oysters were suspensionfeeders. Theodoxus buekkensis was herbivore. Regarding the number of individuals suspensionfeeders are dominant among the bored specimens. 4. Conclusions Activity of Muricid predators can be observed on the shells of bivalves and gastropods collected from four different layers of Wind Brickyard. Three of the above mentioned layers contain the body fossil of Muricids, too. While in the case of "c" layer only the drillholes refer to the presence of the tracemaker. The number of epibenthonic species is higher in every case comparing with inbenthonic species. The percentage of bored individuals is encreasing going from the Molluscan clay to the "c" layer (Dávid, A. 1998) (Fig. 2). Soft bottom and deep water is not preferred by Muricidae. Small size of prey also could have been limiting factor. Growing activity of Muricids is shown by the large number of multiplied borings, too. There are numerous holes can be observed on inbenthonic species collected from the "x" and "k" layers. These refer to the fact that Muricids bored dead specimens, too. Scavangers and suspensionfeeders are the most common preys among the molluscs. Sign of cannibalism is also present in the examined material ("x" and "k" layers). Muricid borings can be observed on the shells of Muricid gastropods. The presence of a herbivore gastropod shell in the deep sublittoral zone bored by a Muricid gastropod is noticeable. We can conclude on transportation in this case. The "c" layer is the only where the number of unfinished borings is higher than the number of successful and unsuccessful borings. Often changing salt content of the sea water, or nearshore currents could cause this phenomena.