I have been focusing on pool swimming for the last stretch of days after the latest bloom of jellyfish in the area. There are more varieties and sizes out there than I really want to contend with, and after slapping my arm across the top of a bright yellow one I figure my luck is about run out with these things. In the interest of justifying this switch to chlorinated waters I will outline a few of the species I have been bumping into, thrashing my arms and legs through, and getting caught in my hair.
Comb Jellies– These are not actually jellyfish, being from a completely different phylum. They are translucent like most jellies, and often are mistaken for moon jellies but are quite different up close. We carefully caught one in a glass jar (they are quite fragile) so we could see one up close. The rows of cilia on the outer surface of their bodies looks bioluminescent, but google says that is simple light refracting through the cilia tissue. There is a slit at one end, and a pencil-point hole at the other, so THIS amateur marine biologist proudly claims to have found the mouth and the anus. Cheers to my liberal arts degree! And they are hermaphroditic, so the one we found could have had its own little ctenophores right there in that jar. They don’t sting, but are fragile enough that getting slapped and kicked by a middle aged swimmer can tend to rupture their outer surface.
Cross Jellyfish– The cross jellies are everywhere. These are the ones I bump into the most. Because, as I may have mentioned, they are everywhere. They look cool, and have firm enough surfaces to be able to gently pick up and look at. Their internal organs form an x like pattern, hence the name. For a child’s intro to jellies there is nothing better. They are a mild nuisance to swimming, at worst giving you that “what just bumped into my stomach under water??” feeling. No stinging involved.
Moon Jellyfish– Another cool looking, non-stinging, bump into your face while swimming variety of jelly. They have horseshoe shaped organs which are visible through the translucent tissue. These are the gonads. They are similar in size and general shape (round) to the Cross Jelly, so for the most part I don’t distinguish between the two. I try not to hit them with my face while swimming, not because of actual discomfort (they rate a 0 on the sting scale), but simply because it feels weird.
Fried Egg Jellyfish– These jellies look awesome from above, the variety in Puget Sound being the Phacellophora jelly. These are the ‘over easy‘ variety, with the milky outer rim, the yellow center, and long tentacles. The tentacles sting a little bit, but bouncing my forearm off the top of one didn’t hurt. However this is where I start feeling a bit jumpy sharing the water. I don’t like that they are hard to see when you are eye level to the surface, and they can be anywhere between a couple inches to a couple feet (60 cm) in diameter, with tentacles extending up to 20 feet (6 m). That is a long ways away for something to be and still be able to get its jelly arms stuck to me. This guy is one or the reasons I shower off after swimming.
Lion’s Mane Jellyfish– Big Reds is what we used to call these when I was a kid. The largest specimen found was 7.5 ft (2.3 m) in diameter with tentacles 121.4 ft (37 m) long. The ones in Puget Sound typically get up to around 20 in (50.8 cm) in diameter, which is big enough for me. And their sting? Well, I will just leave this right here. But heh, at least there is a handy guide to dealing with stings- and it is in pictures!
So these jellies, while fascinating creatures, are the reason for less time in the open waters of Puget Sound and more time in the pool. But that is good, too. It is easier to focus on improving my stroke when I don’t have to worry about breathing in salt water, how fast the current is pushing against me, or which one of these guys is going to end up plastered across my goggles.