The fun part about sea cucumbers isn't their sedentary lifestyle, bland eating habits or squishy, featureless bodies. (We already see that in the US suburbs.) To put it simply, no other animal in my conscious knowledge lives an existence that revolves so much around its anus. Most every aspect of life for echinoderms is tied to their bunghole in some way or another. For instance, sea cucumbers have a unique respiratory system that sucks in water through the cloaca, extracts oxygen and then expels water through the same opening, effectively allowing them to 'breathe' through their anus. ...Thankfully, these creatures lack any true brain to recognize the short, sad lives of filtering water from their asses, but this is only one of the aberrations that makes up a sea cucumber's being.
You just can't have an article on sea cucumbers without mentioning the pearlfish. Pearlfish are usually commensalistic feeders, meaning that they take advantage of other animals but neither kill nor harm them. They're a little rougher on our echinoderm friends, though. As juveniles the pearlfish will drift around for a while until they can stop and make themselves comfortable in, you guessed it, the sea cucumber's anus. Peeking in every now and then to collect waste for food and to shield themselves from attack, the pearlfish will also take a nibble off the gonads or cloacal wall any time they get hungry. They are basically the horrible roommates of the animal world; eating your food, breaking your stuff and always showing up late with the rent.
|Hey buddy, can I borrow $50 for gas? You know I'm good for it.|
Living as a semi-mobile tube of meat comes with its risks, and sea cucumbers are faced by a wide variety of predators such as eels, crabs and humans. Risking life and (metaphorical) limb to venture out into the world and graze the ocean floor, these animals have pioneered a devious mode of self defense. When threatened, sea cucumbers will promptly contract every muscle in their flabby bodies and force a chunk of their respiratory tree, (roughly equivalent to the alveoli and bronchi of vertebrates,) rather violently out of the anus. The slimy, toxic filaments are meant to distract an attacker long enough for the sea cucumber to escape. Due to their regenerative abilities, the loss of some semi-important tissue is preferable to being eaten, and thus a bizarre defense mechanism has proven to be surprisingly effective for the humble but prodigious sea cucumber.
|All they want is some respect. And plankton. Lots of plankton.|
Not only do they fight and breathe through their anuses, but do keep in mind that sea cucumbers, like many ocean dwellers, have only one cloacal opening and therefore reproduce by this all-purpose orifice as well. In conclusion, as you take in all this strangely horrific information on invertebrate life, please be reminded about the wonder of nature and its intense beauty in many other aspects of the world. Run off to look at some kitten pictures or something in hopes of purging this article from your head. But I would like to add that, for the record, any animal who can disembowel itself on command and live earns its share of respect from me. We salute you, sea cucumbers, for defying our flimsy human logic and nauseating our sensitive constitutions for many a generation to come.