Jellyfish and Their Microbial Friends: A Summer-Winter Tale

Jellyfish are more than just sea creatures. They have tiny friends called microbes that live on and inside them. These microbes can change a lot depending on the time of year and where they live on the jellyfish. A recent study looked at Rhopilema nomadica, a big jellyfish in the Eastern Mediterranean Sea. This jellyfish is very common there. Researchers found that the types of microbes living on these jellyfish change a lot between winter and summer. In the summer, when the jellyfish are most active, there are fewer types of microbes. Two types, Endozoicomonas and unclassified Rickettsiales, become more common. In the winter, another type, Tenacibaculum, is more common. This shows that the time of year affects the microbes on jellyfish. Different parts of the jellyfish also have different microbes. For example, Bacteroides are often found on the bell, and Simkaniaceae are often found in the gonads. This means that different parts of the jellyfish provide different homes for microbes. The water around the jellyfish also has some of the same microbes. Endozoicomonas, unclassified Rickettsiales, and Bacteroides are found in the water near the jellyfish but not far away. This suggests that the microbes can move between the jellyfish and the water. The study also looked at nine other jellyfish species. Some microbes, like Endozoicomonas, Mycoplasma, and Spiroplasma, were found on many different jellyfish. However, there was no single type of microbe that was found on all jellyfish. This means that while some microbes are common, each jellyfish species has its own unique mix of microbes. This study is the first to look at how microbes change on Rhopilema nomadica throughout the year. It also provides a lot of new information about how microbes live on jellyfish. The findings show that the relationship between jellyfish and their microbes is complex. It changes with the seasons, the part of the jellyfish, and the water around them. This study is important because it helps us understand more about how jellyfish live and how they affect the ocean. It also shows that microbes play a big role in the lives of jellyfish. Understanding these relationships can help us protect jellyfish and the oceans they live in. It is important to note that this study only looked at one type of jellyfish and more research is needed to fully understand the relationship between microbes and jellyfish.