Sea cucumber in the Seychelles ejects sticky filaments from the anus in self-defense.
Sea cucumbers commune with each other by sending hormone signals through the urine. A noteworthy feature of these animals is the collagen which forms their body wall. This can be loosened and tightened at will. If the animal wants to squeeze through a little opening, it can undo the collagen connections, and pour into the space. To keep itself safe in these cracks, the sea cucumber hooks up all its collagen fibres to make its body firm again. [ 3 ]
The animals have an home respiratory tree which floats in the internal watery cavity. At the rear, water is pumped in and out of the cloaca, [ 4 ] sol gaseous exchange takes home with the resiratory tree in the intestine. [ 5 ] p80
Some species of coral reef sea cucumbers defend themselves by expelling gluey cuvierian tubules to entangle potential predators. These tubules are attached to the respiratory tree in the intestine. When startled, these cucumbers may expel the tubules through a tear in the wall of the cloaca. In effect, this squirts sticky threads all over a predator. substitute tubules grow back in one-and-a-half to five weeks, depending on the species. [ 6 ] The acquittance of these tubules can besides be accompanied by the discharge of a toxic chemical known as holothurin, which has similar properties to soap. This chemical can kill any animal in the vicinity and is one more way in which these sedentary animals can defend themselves. [ 3 ] other cucumbers, lacking this device, can split their intestinal wall, and spew out their catgut and respiratory tree. They regenerate them late. Zoologists who experience this believe it to be an impressive deterrent. “ The fix one individual can make must be seen to be believed ”. [ 5 ] p81 The being of these defences explains why the holothurians were able to do without the hard skeletal system of their ancestors .
Highly modified tube feet around the mouth are constantly present. These are branched and retractile tentacles, much larger than the regular metro feet. Sea cucumbers have between ten and thirty such tentacles, depending on the species. There is a resound of larger ossicles round the mouth and esophagus to which the muscles of the tube feet are attached. [ 7 ] With their gluey tentacles the animal collects detritus and small organisms .
