Stalked jellyfish
These days in early aurumn it is possible to find so called stalked jellyfish (in German "beaker jellyfish") in the seagrass meadows in the bay between Strande and Bülk in the Kiel fjord. Stalked jellyfish or Stauromedusae are Cnidarians and are related with the common jellyfish. This group has characteristics from medusae and polyps and most members of this group are not higher then 4 cm.
Craterolophus convolulus, die Schlanke Becherqualle (Foto: A. Czerniak)
Sometimes it is not necessary to go diving to see an interesting new species - snorkeling will do. In the shallow bay between Strande and Bülk in the Kiel fjord it is possible to see curious members of the cnidarians already in depths of 1.5 to 1.8 m. Stalked jellyfish have their tentakles on so called arms and these are arranged in a circle. The so called "beaker" is specific for this group.
The domestic species are Crateropholus convolvulus and Lucernaria quadricornis. The specimen on the image presented in this text is most likely C. convolvulus. According to the literature, this species is not dnecessarily omestic in the Baltic, but this itatus keeps changing for a lot of species right now.
Stauromedusae have characteristics of the free floating medusae and the sessile polyps. The "beaker" corresponds to the umbrella of the medusae, but its ring muscle is reduced. The most mebers of the approximately 50 known species are not completely and permanent attached to the substratum - they can move if neccessary. Some species nevertheless secret a hard substance (like Chitin) that glues them permanently to the groud. Thus, these species are not capable of leaving their "seat" anymore.
