A POST HERE SEVERAL MONTHS AGO closed with the “Really Odd Fact” that blenny-like pearlfish (Periclimenes imperator) have a habit of taking up residence in the … well…rear ends of sea cucumbers.
The overall post, “Sea Cucumbers – Superheroes of the Sea,” was about the fact that sea cucumbers, often ignored as inert, unimportant creatures, actually had a lot to recommend them.
THE PEARLFISH/CUCUMBER EQUATION
The pearlfish/cuke interaction is generally described as commensal relationship, but that term implies a mutually beneficial arrangement between two organisms. But in this case, it’s not clear the sea cucumber has much say in the equation. Or benefit.
PEARLFISH FILM AT 11!
I’ve since come across a video from BBC Earth showing a pearlfish and a sea cuke in action. It explains a lot about the relationship.
The narrator tends to make a thing about pearlfishes’ choice of habitat as being less than desirable, considering there’s excrement involved. Well, the video’s title is “Pearlfish’s Gross Hiding Spot…Inside a Sea Cumcumber.”
Perhaps. But I have a thought. It’s that canines are renowned for having a zillion times better sense of smell than us humans.
Having owned a number of dogs, I’ve always thought that the remarkable thing is that along with their superpowers of odor-sensitivity, they appear to have no discretion at all about what they are smelling. Perhaps excrement isn’t as appealing as a nice, medium-rare steak, but dogs certainly do find it interesting.
NATURE AT WORK
In any event, fish that live in sea cukes’ posteriors are part of the natural world, and the video is elucidating. Also informative. And interesting.