October 2010

Sven Hammann reports about his miniproposal.


Developing Methods to Analyze the Physical Surface Characteristics of the Combjelly Mnemiopsis Leidyi

Sven Hammann, ISOS PhD, Department of Zoology, CAU Kiel

Living in the coastal waters of northern America, from the Gulf of Mexico to the Canadian coast the comb jelly Mnemiopsis leidyi is extremely matchable to different environmental conditions. It tolerates a salinity range from 4 to 35 and a temperature span from 4 to more than 30°C, this being excellent conditions to make it a highly invasive species.

Sven's thesis focuses on the symbiotic interactions of M. leidyi and its potential symbionts. During his work some evidence arose, that the surface of the jelly is completely free of bacteria. This is especially amazing considering the fact that seawater is far away from being “clean”. Actually it is more a suspension of bacteria, archea, viruses, and small eukaryotes.

Though most creatures obviously have good control of settlements on their surfaces M. leidyi seems to be the only organism that manages to keep its surface completely free of bacteria. But the underlying mechanisms are yet unknown. This was the starting point of Sven Hammann’s miniproposal.