Month: June 2022

So you got your sea slug, and you need to know what the fuck its anatomy even is. A very normal situation.

Above, you’ll see a diagram of a variable neon sea slug, also known as the dusky nembrotha. This is a type of dorid nudibranch, so some features may not be present in other species of sea slugs.

Let’s start from the top. Rhinophores are sea slugs’ sensory organs, and every species of sea slug has a pair; any number of rhinophores other than two is the result of a mutation (or an attack). They look soft and a bit like you took a feather-duster and hacked away at it with a pair of scissors. Next up is the oral veil. I’ll admit, there is no oral veil on the variable neon sea slug (I think), but I labelled it because a lot of species have an oral veil. This feature covers the sensitive oral tentacles and looks a bit like a hood. Oral tentacles are used to feel around and help the sea slug sense its surroundings. This is because their eyes absolutely suck. You may have noticed I didn’t label the eyes in the diagram, and that is because I couldn’t figure out where the eyes were on my reference image due to their tiny size.

Now to talk about the mantle. Not referring to the largest layer of Earth, sandwiched between the crust and core of our beloved planet. No, I’m referring to the thing in the diagram that I labelled. The mantle is most of the main body of the sea slug and is rather self-explanatory. If you’re confused, search up pictures of terrestrial sea slug mantles and you’ll get the idea. The foot is the end bit of the slug and does not house any major organs (to my knowledge). Sometimes there’s a visible transition from mantle to foot because some species have a mantle skirt, but most of the time it’s anyone’s guess.

You may have noticed that I skipped over the branchial plume. This is because it’s a feature only present in dorid nudibranchs. Thus, I’ll cover it in the nudibranch post coming up next week.

Now you know a bunch of weird buzzwords pertaining to sea slug anatomy. Go out and impress the nearest stranger with your knowledge to the point they think you’re a chronic drunk (I would say go talk to your friends, but if you’re here, I doubt you have any).

HAPPY PRIDE MONTH

Alrighty. Time to talk about my passion: sea slugs.

FIRST OFF: What the fuck is a sea slug? Well, according to Wikipedia, the sea slug label applies to “some marine invertebrates with varying levels of resemblance to terrestrial slugs”. That’s a fancy way of saying it’s a slug that lives in the sea. For the sake of this, you just need to know that sea slugs are gastropods in the mollusk phylum (taxonomical term for a group smaller than a kingdom and larger than a class).

These lovely creatures can be divided into three groups, also known as clades/orders:

• Nudibranchs: the vibrant and poisonous ones (an example being the internet-famous sea bunny)
• Sacoglossans: the ones that look like plants and behave like plants (most of the time)
• Sea hares: the dull (boring) ones that sometimes look like a taco

Now, because I adore sea slugs (some more than others), I’m going to make this a series! I’m definitely going to cover the different clades of sea slugs as well as their anatomy, and I might dedicate a few posts to specific species of sea slugs. Also, if this interests you, I’d suggest looking through the Sea Slug Forum; it’s a website with a bunch of posts about sea slugs, and it was made by a malacologist (someone who studies mollusks)!

HAPPY PRIDE MONTH