The sea cucumber is an often overlooked animal. Even though it is named after the green vegetable that makes up most of our salads, it more closely resembles a pickle with an odd texture on the outside. The sea cucumber is a bottom feeder. In today’s society, this term is used to describe some unsavory types of people, but in nature it just represents a group of animals that dwell on the ocean floor clearing various debris.
They do not possess a brain and they are entirely made up of nerves that can be found around their mouth, down their entire body, and all the way to the tips of their tentacles. Using these tentacles they collect detritus found on the seafloor. They achieve this by using their modified tube feet, not unlike the ones found on starfish. These tentacles can be rather intricate and similar to the ends of a neuron or to the branches of a tree.
They can extend them above their bodies and catch floating detritus or lower them to the ground and collect it from the ocean floor. As they collect the food and digest it they pump out clean sand that covers the seabed. Because of the way they feed they have a specific taste that is very popular in countries like China and Korea.
Their feeding process might seem dirty and disgusting but it is very important for keeping the ocean floors clean. They collect the dirt from the water and from the sea floor and they expel clean sand. This is a similar action that earthworms perform on dry land, as they recycle decomposing matter and aerate the seabed.
In recent years, the demand for sea cucumbers has been on the rise and for that reason, their numbers are dwindling overall. As there are fewer sea cucumbers around, the water becomes murkier and harder for fish to traverse. Also, the once clean and soft seafloor is becoming stiff and hard to live on. Even more importantly, the extra detritus available in the water can cause a rise in the number of algae in the water. As the number of algae increases, so do the oxygen levels decrease causing animal and plant life to suffocate. Entire species can die off in this way, causing a catastrophic shift in the sea’s ecosystem.
Unfortunately,similar to people on the surface, the animals in the sea do not recognize the hard work performed by someone else until its too late. Sea cucumbers often serve as easy prey for larger predators. Fortunately for them, sea cucumbers have developed defense mechanisms allowing them to survive various attacks. One of the species of sea cucumbers is capable of ejecting their respiratory organs through their anus and waving them around behind them. If an animal is curious enough they will be met by the toxic chemicals lining the organ. Other species can go deep into the ground in order to hide from bigger fish.
But both of these actions are time-consuming and really take a toll on the cucumber’s body. Fortunately enough, they also have a hidden superpower. When they feel threatened and eject their organs from their backsides, they can also turn completely rigid. In this form, they have the consistency of hard plastic and become a really difficult treat to consume.
The cucumber achieves this by using its network of collagen fibers, otherwise known as fibrils which are embedded under the skin of the cucumber. As pressure is applied the fibrils connect and form a hard layer that has structure and strength. Similar to beams in construction, shaking one shakes them all and that gives them their strength, as the pressure is equally spread over the entire surface area. The collagen fibrils in the skin from a structure that is able to transfer stress equally, without breaking.