Giant California sea cucumber or holothurian Parastichopus californicus — a unique natural phenomenon. It uses the anus as a second mouth, despite the fact that this, too, his mouth is.
Scientists had known earlier that the shallow-water marine invertebrates that live near the Pacific coast of North America, use the anus for breathing. Because they do not have lungs for breathing used vodnososudistaya tentacle system which consists of a plurality of channels extending throughout the body. Branched bags to help breathing goloturii receive oxygen when water is injected into the anus through the rectal muscle.
Half-meter sea cucumbers, which are predominantly fixed way of life and are even a permanent home for some of the tiny inhabitants of the sea floor, can handle up to 800 milliliters of water every hour. The body of these animals eliminates oxygen from the other components of sea water and saturate them with their cell.
Dr. William Dzhekl (William Jaeckle) of Illinois Wesleyan University and Richard Strathmann (Richard Strathmann) from the University of Washington decided to study these amazing creatures in more detail.
They found that the system of blood vessels connecting the breathing bags of branched intestine (called the rete mirabile), is not for the transport of oxygen to the intestines. From a scientific point of view, it would be logical to assume that this structure is needed for the transfer of food from the intestine to the anus, and not vice versa, as is usually the case in animals. Zoologists have decided to test their hypothesis.
In order to confirm their hypothesis, the researchers fed a giant sea cucumbers radioactive algae that contain iron particles. With this trick, the team was able to trace all the way, which makes food for the body of echinoderms. Moreover, radioactive particles that accumulate in the body, where the opening, through which the food being consumed.
The results showed that sea cucumbers feed primarily through the mouth. But the high concentration of radioactive particles and iron are also observed in the structure of the rete mirabile, which proves that the use of sea cucumbers anus as a second mouth. It turns out that the anus of these creatures carries as many as three vital functions: respiratory, nutritional and excretory.
Scientists say that only one type of study sea cucumber does not mean that they are used only a bipolar power technique. Later zoologists intend to study other types of echinoderms.
The results of the study were published in the March issue of the journal Invertebrate Biology.