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We're learning about comb jellies this week, along with the sea sponge, and the MASSIVE CONTROVERSY ABOUT THE TWO THAT IS PITTING SCIENTIST AGAINST SCIENTIST I might be overstating it just a bit The lovely Arctic comb jelly: The lovely Venus's girdle comb jelly: A fossil comb jelly. Probably lovely when it was alive: A sea sponge (most are not this Muppet-like): Show transcript: Welcome to Strange Animals Podcast. I’m your host, Kate Shaw. For this week’s episode, we’re revisiting jellyfish, more properly known as jellies. The first jelly episode is far and away our most popular and I can’t figure out why. I mean, I’m glad people like it. This time, we’re going to learn all about comb jellies, which are not really as exciting as true jellies. There is no ship-sinkingly enormous comb jelly lurking in the oceans of the world. But they are really interesting. When you think of a jelly, you probably picture a roughly bell-shaped thing with long stinging tentacles. But most comb jellies are more like egg-shaped blobs, and either don’t have tentacles at all or only have relatively small tentacles that don’t sting. Although they look alike superficially, comb jellies and true jellies are so different that scientists don’t think they’re very closely related at all. Comb jellies are officially called ctenophores (TEN-oh-fours), spelled with a c-t at the beginning if you were wondering. I looked up the pronunciation. Yeah, I know, I pronounced Pliny wrong all through episode 12, but come on, it looks like it should be pronounced Pliny and not Plinny. It’s not like anyone ever came up to me and said, “Hey, what about that Plinny, what a guy.” I just read the name. But I digress, inexplicably. Instead of pulsing its bell to maneuver in the water, a comb jelly has rows of tiny compact filaments called cilia, fused together in combs that help it swim. The combs are also called swimming plates. There are two main types of comb jellies, those with tentacles and those without tentacles. The ones without are called Nuda, or Beroids, and while they don’t have tentacles, they do have combs of extra-large cilia, called macrocilia, that sever prey into pieces small enough to swallow. Mostly they eat other comb jellies. Beroids also have big mouths, but a beroid can actually seal its mouth shut while it’s moving so it’s more streamlined. Comb jellies with tentacles are divided into eight orders roughly based on body shape. The most common order, the cydippida, are egg-shaped with a pair of thin tentacles that they use sort of like fishing lines. The tentacles are long and sticky, trapping tiny organisms or particles of food. Some species have branched tentacles but none have more than two. The tentacles can retract—when you see a picture of a comb jelly with a weird spring-like thing sticking out from its bottom, that’s a retracted tentacle, not anything gross like a poop. The tentacles contain cells called colloblasts. When an organism touches a tentacle, the colloblast cells rupture and basically release glue that keeps the prey from escaping. A cydippid comb jelly also has eight combs that run from the top of the body to the bottom, which makes it look sort of like a fancy decorated egg. Comb jelly cilia are iridescent, by the way, so they reflect light in rainbow patterns. Basically what I’m saying is, these little guys are actually really pretty. All comb jellies are predators, but most eat plankton and other tiny food, because most comb jellies are really small—only a few inches long at most. Bigger species may eat krill and small crustaceans. The biggest comb jelly, Cestum veneris, more often called Venus’s girdle, can grow some five feet long, or 1.5 meters, but only some two inches, or 5 cm, wide. It looks like a nearly transparent or purplish ribbon and lives in tropical and subtropical seas. I wouldn’t want to touch it, but it’s not exactly dangerous. In fact,