Polychaeta. Class Polychaeta

Polychaeta Definition & Meaning

A gradual increase of stiffness from the surface to the interior is known to prevent crack formation and improve the ability of stiff materials to resist contact damage Suresh et al.

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ADW: Polychaeta: INFORMATION

Perhaps the most unusual occurs in Bonellia viridis , an echiuroid now included within Polychaeta. Notably most Syllidae, Nereididae, and some Eunicidae Palolo worms metamorphose to become night-time swimmers to meet their mates, with timing of swarmings synchronised with the phases of the moon.

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Class Polychaeta (Poly, many + chaise, hair)

They were present in the middle Cambrian in the Burgess Shale in taxa resembling, in certain respects, recent canalipalpates. Whether such hermaphrodites are self-fertile or not is species-specific and often has not been determined. The body also contains greenish "chloragogen" tissue, similar to that found in , which appears to function in metabolism, in a similar fashion to that of the vertebrate.

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CLASSE POLYCHAETA PDF

Food is drawn inward by the sucking action of their muscular pharynx. The posterior segments make up the epitokal region, consisting of segments packed with gametes.

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Polychaete

Their major features match the polychaetes well, and they are included here as a single family of polychaetes, Siboglinidae. Polychaetes play an important role in turning over bottom sediments in the sea. In these cases, the adult soon dies.

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Class Polychaeta

The upshot of the scattered records shows that most major taxa of polychaetes must have been present by the Ordovician and some clades may be even older than that.

Class Polychaeta (Poly, many + chaise, hair)

Eyes: Polychaetes have various sensory structures. PM, plasma membrane; cc, cortical cytomembranes; m, mitochondrion. They have more than 5.

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