Busy little bee

Today is, I think, my only day off for the next two weeks. I'll be back inside the aquarium for the winter, in a part-time job working raising jellyfish; with any luck I'll be able to find some hours in the Education department as well. I start that job tomorrow, and will be doing that on my days off from the whale watch before the end of the season, but that's really only about twelve days from now so I'm not too concerned.

I'm excited about the jellies. I've worked with them before, though in a slightly different context: I was an aquarist (marine zookeeper) in an exhibit that focused heavily on jellies, while now I'll be one in a lab that raises them. I don't have much experience with the pre-adult stages, and I'm looking forward to that part.

Jellyfish husbandry is very different than actual fish, simply as a result of their odd physiology. They're around 95% water, and are so gelatinous that getting caught in a sharp corner or scraped along gravel would kill one. In fact, an air bubble caught beneath the bell (the part that looks like a mushroom's cap) will float up through the animal's body, leaving a lethal hole. Most jellies have to be kept in rounded tanks designed with a current that keeps the animals suspended in the middle of the water. Even siphoning detritus off the tank bottom needs to be done with extreme caution: a jelly that comes within a few inches of the hose will get shredded by the sheering stress of the vacuum. Moving them from tank to tank provides similar problems: many species will collapse or tear apart under their own weight if lifted out of the water, and containers used to transport them must be free of even slightly-abrasive sides, unless you want your jellies to get scratched to pieces.

There are other interesting problems: a jelly that isn't feeding well will actually shrink in size, and different species will be surprisingly picky about what they eat. Some need chunky foods, like chopped moon jellies or blended fish; others will drop anything larger than, say, an adult brine shrimp. Some species have endosymbiotic zooxanthellae (I like saying that) and have the same lighting requirements as a plant: in fact, those zooxanthellae are plants, microscopic dinoflagellates, living in the jelly's body, providing food in exchange for protection.

So we will hear more of jellyfish soon.