Tag Archives: Evisceration

The Spineless Gutless Sea Cucumber

Sea cucumbers: those cute log-like animals munching their way along the sea floor. These cylindric invertebrates are part of the phylum Echinodermata which translates to “spiny skin”.

Echinodermata is a completely marine based phylum that includes sea stars, sea urchins and of course, the lovable sea cucumbers. Most days you can find innocent sea cucumbers minding their own business and sucking up sand and mud like a vacuum. The sea cucumber sifts through and feeds on the organic pieces hidden in the sediment. If you have visited CIMI, you may have had the pleasure of holding a sea cucumber that can be found in our cove, Parasichopus californicus, or the warty sea cucumber. A muddy orange-brown color, these guys are named after the wart like bumps that cover their body.

Spineless Sea Cucumber

Sea cucumbers, like the warty sea cucumber, are eaten by a number of different organisms. Predators include types of crabs, fish, sea stars and sometimes sea turtles. How do these spineless logs defend themselves against predators? They can not move very fast, so a quick escape is rarely an option. Sea Cucumbers have evolved a very interesting and gross way to escape possible death by crab or fish. Evisceration!

Spineless Sea Cucumber 2

Evisceration basically means exploding guts. The root word in eviseration, “visera” means “intestines”. When a sea cucumber feels threatened it can spew its intestines and other internal organs at a predator. The predator is distracted by the free snack, allowing the sea cucumber to inch away. Evisceration begins when the attatchment tissues that hold the internal organs, like the intestines or respratory gills, soften. If you’ve ever touched a sea cucumber you’ll have noticed that its body toughens and becomes rigid. Left alone it will losen up and soften again. Like many echinoderms, sea cucumbers can toughen or soften their body texture at will. Once the attachment tissue softens and becomes almost liquidfied, spots on the body where the organs will soon spew out begin to soften too. Depending on the species, the evisteration point can be on the anterior (front) or the posterior (back) end of the sea cucumber. Softening takes between one to three minutes. The sea cucumber muscles contract and expell the internal organs! It can take between 20 minutes to 12 hours to complete the process of eviseration. Now that the sea cuumber has rid itself of most its organs and escaped being eaten, it must begin to regenerate. Regenerating its interal organs can take as long as 145 days and as short as 7 days. It depends on the species, age of the organism and the time of year.

Although evisceration is often associated with defense and escape, this is not always the case. It depends on the species of sea cucumber. Some sepecies, like the warty sea cucumber, eviserate seasonally to get rid of excess waste. In addition, during food shortages, sea cucumbers have been know to eviserate. It is actually a larger metabolic load or energy drain on the sea cucumber to hold onto excess waste than to eviserate and regenerate.

Sea cucumbers are pretty amazing! They can live without their internal organs for weeks and spew their guts at predators. They might be gutless at times, and spineless, but they got a lot of spunk for an animal named after a cucumber.

Sources:

http://echinoblog.blogspot.com/2012/01/sea-cucumber-evisceration-defense.html

http://www.asnailsodyssey.com/LEARNABOUT/CUCUMBER/cucuEvis.php

Photo:

Leopard sea Cucumber – http://phenomena.nationalgeographic.com/2016/05/10/how-this-fish-survives-in-a-sea-cucumbers-bum/

Sea Cucumbers: The More You Know

Sea cucumbers are a species of invertebrates under the phylum Echinodermata similar to sea stars and sea urchins. Sea cucumbers live in the benthic zone or ocean floor. They are nocturnal creatures but can be seen in the day as well. Sea cucumber uses their tube feet for locomotion and eating. The mouth is surrounded by twenty retractable tentacles that help them bring food in. They may seem slow, but have a very effective defense mechanism called evisceration in which they can jettison their internal organs to distract or in hopes their prey will eat their organs instead of attacking them. Sea cucumbers can regenerate these organs within days.

Sea cucumbers diets consist of algae, aquatic invertebrates, and waste particles in the ocean. Sea cucumbers are in high demands in Asian markets for their use in medicine and food. Sea cucumbers reproduce by the female launching her eggs in the waters, the male does a similar process with his sperm. Sea cucumbers can also self-reproduce as well.

Sea cucumber’s shape is elongated and is found on the sea floor worldwide. The most common species found on Catalina Island include the warty sea cucumber and the giant California sea cucumber.

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Evisceration

Sea cucumbers are a member of the phylum Echinodermata, which means “spiny skin”. Other members of this phylum include sea stars, sea urchins and sand dollars.  The most notable characteristic of this phylum is their ability to regenerate tissue, organs and limbs. Some organisms can regenerate their entire structure from a single limb! The warty sea cucumber can be found on the ocean floor sediment off the coast of Catalina Island. When handled roughly or threatened by a predator, sea cucumbers can tear away and expel parts of their gut in a process called evisceration. The eviscerated internal structures serve as a distraction and easy meal for the opposing predator, allowing the sea cucumber to escape on its tube feet and regenerate the missing parts.

At CIMI, we are fascinated with this process. So fascinated, in fact, that it has become a staple game for our kayak expeditions! Anyone who’s been kayaking at CIMI has probably heard of or played evisceration. The object of the game is to get an inflated ball to the moving goals, which are the instructors in their kayaks. When a kayak has the ball in their boat, the other team can tag the side of their boat and yell “evisceration!” Then, like the warty sea cucumber, the ball holders must eviscerate by throwing the ball far behind them without looking at where it is headed. Then, any boat can grab it from the water, and the game continues!

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