The eco-physiology of some exotic Ctenophora (Pleurobrachia pileus O. F. Müler, 1976, Beroe ovata Mayer, 1912) and Scyphozoa (Aurelia aurita Linnaeus, 1758) in the South Eastern Black Sea

SUMMARY The Eco-Physiotogy of Some Exotic Ctenophora (Pleurobrachia pileus O. F. Müler, 1976» Beroe ovata Mayer, 1912) and Scyphozoa {Aurelia aurita Linnaeus, 1758) in the South Eastern Black Sea In this study, the eco-physiology of some exotic ctenophores (Pleurobrachia pileus, Beroe ovata) and Scyphozoa (Aurelia aurita) in the South Eastern Black Sea, Trabzon, were studied. This study consists of two parts: Laboratory and field studies. In the stated laboratory conditions gastric emptying in P. pileus fed on Artemia salina nauplii was studied and it was best described by an exponential function. The study has also indicated that gastric emptying time has increased linearly by increasing prey number ingested. In the mean time container volume has significantly affected the clearance rate in P. pileus fed on Artemia salina nauplii. The clearance rate of B. ovata fed on P. pileus was also investigated and found that when the volume increases so does the clearance rate. The experimets conducted in the laboratory conditions have indicated that they mainly feed in the day time and prefer jelatinious animals when they have to choose. The food consumption was also studied and found that B. ovata consumes as high as 34-215 % bw per day. In the field; abundance and vertical distribution of P. pileus, B. ovata and A. aurita by months were investigated. The stomach contents were also studied. The abundance of P. pileus, B. ovata and A. aurita were vertically and seasonally investigated. The feeding ecology of these animals were also studied. The density of P. pileus was found to be high especially in spring at the depth between 75 to 150 m. Where as A. aurita was more abundant at 0 to 75 m especially in June 2002. the investigation has also shown that there is a diverse relation between the abundance of P. pileus and B. ovata. The study on feeding ecology of jelly s concerned has shown that the main prey items for P. pileus were zooplankton and microplankton for all months investigated while A. aurita feed mainly zooplanktonic organisms in the area covered. Key Words : South Eastern Black Sea, Pleurobrachia pileus, Beroe ovata, Aurelia aurita, Feeding Eco-Physiology vm