What are polychaets?

Polychates are a class of ubiquitous segmented worms, mostly sea, although several species have adapted to earthly life in wet areas. They are Annelids, sea counterparts of earthly annelids such as earthworms. "Polychhate" means "many hair", "reference to chitin hair that protrudes from both sides of their bodies, with the same set of hair to the segment. Just like earthly annelids have the advantage over simpler worms because In Sirius Passset Lagerstatte, they may date the segmented hollow skeleton tubes ( clouda ), reminiscent of the tubes used by some modern polychaes, although the consensus is missing. the skeletons and the oldest fossilsLie that shows evidence of predatory boreholes.

There are about 10,000 species of polychaettes, with a great variety of lifestyles and adaptation. Some, like Lugworm, spend their entire lives in the U -shaped normal zone. The curled castings discarded above the surface are clearly visible on the beaches when the tide comes out, and the fisherman sometimes digs the worms to be used as a bait.

Another typical polychaette is a common clam that catches eyelashes and other worms on the seabed and provides an important source of food for crustaceans and fish carrying the bottom. When it is time for the worm to be reproduced, it is plugged into the reproductive mode unique to the polychaets, epitoks. During the epitocoon, the worm's body suddenly changes stronger pendants, producing egg and sperm and increase sensory and motor centers at the expense of the digestive system. Flow from bottom to top into a pelagic zone, where plankton lives, and ejects its gameter package where it mixes with gametes from other worms to produce larvae. These larvae feed on plankton, eventually sinking to the bottom and changing to worms.

Some remarkable polychaettes have learned to adapt to the most unusual environment. For example, a flower with a bone is a recently discovered family that is located on whale waterfalls, a corpses that sink to the bottom of the sea. With the help of bacteria, which is so symbiotic, it is suppressed into the bones that it does not require stomach or mouth, instead absorbs nutrients with an odd root structure. Pompeii, another Polychaet on the bottom, which lives on bacteria around the hydrothermal holes, is one of the most heat -bent organisms, capable of withstanding temperatures up to 80 degrees C (176 ° F). Another Polychhate, Lamellibrachia , is one of the longest animals in the world, with age up to 250 years.