Which characteristic is unique to polychaete annelids?

Answer and Explanation: The paraphyletic group of marine annelids which bear the characteristic chitinous bristles called parapodia is polychaete annelids. The parapodia are highly vascularized and contain numerous minute projections called chaetae.

What is the most obvious feature of polychaetes?

Polychaetes are particularly common on and in muddy and sandy shores. Their most obvious feature are the pairs of parapodia appendages. One pair comes from each body segment. These parapodia are used for crawling and swimming.

What is Polychaeta example?

Polychaete/Lower classifications

What characteristics distinguish the oligochaeta from the Polychaeta?

The main difference between polychaetes and oligochaetes is that the polychaetes have a pair of parapodia per body segment that bear many bristles. But, oligochaetes have few bristles on their outer surface of the body but, no parapodia.

How do you identify polychaetes?

The polychaetes are segmented worms (Phylum Annelida), as are earthworms (Oligochaeta). The polychaetes can be distinguished by having paired, lateral appendages, parapodia, on each segment. The parapodia are usually divided into dorsal notopodia and ventral neuropodia.

What is the habitat of Polychaeta?

Polychaetes are multi-segmented worms living in all environments in the world’s oceans, present from abyssal depths to shallow estuaries and rocky shores, and even free swimming in open water. They are strictly aquatic annelids, but are the most abundant and diverse group of Phylum Annelida.

What are characteristics of Oligochaeta?

Oligochaetes, which range in length from a few millimetres (a fraction of an inch) to more than 3 m (10 feet), are notable for the absence of a head and parapodia, the flat, lobelike outgrowths used by many polychaete annelids (class Polychaeta) for locomotion. They have few setae, or bristles, on the body.

What are the characteristics of class Oligochaeta?

The Oligochaeta includes the well-known earthworms and many small species of freshwater worms. They are part of the Phylum Annelida; the segmented worms, and if magnified the body is visibly segmented. Oligochaetes are also distinguished by the presence of hair-like or bristle-like setae (or chetae) along the body.

What is the common name for Polychaeta?

bristleworms
Polychaetes are known by many names: lugworms, clam worms, bristleworms, fire worms, palolo worms, sea mice, featherduster worms, etc., but all possess an array of bristles on their many leg-like parapodia — the name polychaete, in fact, means “many bristles”.

What is unique about the class polychaeta?

Polychaetes, which include rag worms, lugworms, bloodworms, sea mice, and others, are marine worms notable for well-defined segmentation of the body. Unique among annelids, most polychaete body segments bear a pair of parapodia (flat, lobelike outgrowths) with setae, or tiny bristles.

What is the main features of nereis?

Nereis worms are commonly known as rag worms or clam worms. The body is long, slender, and dorso-ventrally flattened, reaching a length of 5-30 cm. The head consists of two parts: a roughly triangular anterior lobe—the prostomium—and a posterior ring-like portion—the peristomium.

How do polychaetes differ from earthworms?

Earthworms differ from polychaetes in that they do not have parapodia but DO possess a clitellum, which is used in reproduction. Though most live in the upper layers of the soil there are freshwater species within this group.

Do polychaetes have eyes?

The polychaete Fabricia has eyes at both ends of its body, a useful thing to have, since it usually swims backwards. In contrast to free-swimming species, sessile polychaetes will often lack complicated sense organs on their heads.

What is the other name of Nereis?

clam worm
rag worm, also called clam worm (genus Nereis), any of a group of mostly marine or shore worms of the class Polychaeta (phylum Annelida). A few species live in fresh water. Other common names include mussel worm, pileworm, and sandworm.

What is the Locomotory structure of Nereis?

Parapodia is the locomotory structure of Nereis. They possess longitudinal and circular muscles that help in locomotion. Aquatic annelids like Nereis possess lateral appendages, parapodia, which help in swimming.

What is Nereis called?

A. ringworm. No worries! We’ve got your back.

What is the common name for Polychaeta?

bristleworms
Polychaetes are known by many names: lugworms, clam worms, bristleworms, fire worms, palolo worms, sea mice, featherduster worms, etc., but all possess an array of bristles on their many leg-like parapodia — the name polychaete, in fact, means “many bristles”.

How many eyes do Nereis have?

The prostomia of nereid worms are quite alike, with four eyes, a pair of frontal antennae and biarticulate palps, and 3–4 pairs of tentacular cirri.