Nereis or Neanthes is a marine polychaete annelid that lives in burrows in sea bottom and comes out in wickedness to prey upon bantam animals. N. virens  (Sandworm), N. pelagica (Type-species) and N. succinea (Clam worm) are common species of Nereis.          Body of Nereis is dorsoventrally flattened, segmental and 30-40 cm long having 80 to 120 segments and cleavable into acron, trunk and pygidium. Acron is divisible into anterior prostomium and posterior peristomium and a allow out in between on the ventral nerve.  luggage compartment is metamerically segmented and segments are called metameres or somites each one of which bears a couplet of parapodia. The last segment is called pygidium that bears an anus slightly on the abaxial font and a pair of thread like anal cirri and several(prenominal) minute sensory papillae on the dorsal status. PARAPODIUM          Parapodia are diametric locomotory organs of th e body attached on the lateral side of each trunk segment. Each parapodium is made of two lobes, that is to grade dorsally placed notopodium and ventrally placed neuropodium. Both lobes fire thread-like appendages called dorsal and ventral cirri. The two lobes of parapodium are supported internally by two chitinous rods known as aciculum, on the apical part of which at that place are bundles of long, chitinous setae or chaetae which project beyond the outermost margin. Nephridiopore is situated on the parapodium snug the ventral cirrus. SKIN         Skin is made of marvelous columnar cells and disjointed glandular and sensory cells and is richly supplied with telephone line vessels. Outer come along of epidermis is coated with a layer of tough cuticle which carries a number of small pores for glands. Below the epidermis there are circular and longitudinal muscles in bundles and some abdominal external oblique muscle strands that help to carry out later al undulation of body. coelom      Â!   The celom is schizocoelom but true perivisceral cavity that is made of an outer parietal peritoneum and an inner visceral peritoneum that surrounds the alimentary...If you want to get a just essay, order it on our website: OrderEssay.net
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