What are the similarities between polychaeta and oligochaeta?

Similarities Between Polychaetes and Oligochaetes Polychaetes and oligochaetes are two subclasses of the phylum Annelida. Both can be free-living. Also, both have a true coelom derived from the mesoderm. Further, they both have a segmented body with bilateral symmetry.

What differentiates polychaetes from other annelids?

Polychaetes differ from other annelids in having a well differentiated head with specialized sense organs and no clitellum. They have many setae, usually arranged in bundles on the parapodia. The sense organs in polychaetes are more highly developed than in oligochaetes.

What physical characteristics do all polychaetes have in common?

Physical characteristics The majority of polychaetes have a cylindrical and elongated body. The parapodia can be unirramous or biramous, with a dorsal lobe (notopodium) and ventral lobe (neuropodium). The body morphology of polychaetes usually reflects their habits and habitats.

What are the morphological similarities and differences between nematodes and annelids?

Phylum Nematoda and Annelida are two phyla of kingdom Animalia. Nematodes are cylindrical and roundworms with un-segmented bodies. Annelids are segmented worms. They possess a true coelom, unlike nematodes which have a pseudocoelom.

What four ways do polychaetes differ from oligochaetes?

Polychaete: mostly marine segmented worms. well developed head, each segment usually has parapapodia with chaetae, tube-dawelling and free moving. Oligochaeta: freshwater, marine, and terrestrial segmented worms such as earthworms, reduced head, no parapodia, chaetae present.

What class does leech belong to?

Clitellata
Leech/Class
Classically, oligochaetes and leeches are placed within the phylum Annelida either in the order Hirudinea, class Clitellata, or in the class Euhirudinea.

What do leeches and oligochaetes have in common?

The Acanthobdellae are considered to be the link between the oligochaetes and leeches because they possess setae and walls between segments; the order contains only one known species, however. The three remaining orders of leeches evolved into two lines based on whether or not the animals have jaws.

Do polychaetes have eyes?

The prostomium, the front portion of the head which extends out above the mouth, bears four eyes, palps and tentacles, an impressive array of sensory organs. The eyes of some polychaetes are quite complex, and a single individual may have eyes using two different mechanisms for vision.

Are polychaetes poisonous?

Of the many species of worms, the bristleworm is one of the most dangerous. Bristleworms are elongated segmented worms. Each segment contains a pair of bristles. Although bristleworms are not aggressive, they bite when handled, and the bristles can penetrate skin (sting).

What do all worms have in common?

They all have long, narrow bodies without legs. All worms also have tissues, organs, and organ systems. Worms have bilateral symmetry. Unlike sponges or cnidarians, worms have distinct head and tail ends.

What do nematodes and arthropods have in common?

The nematodes, or roundworms, possess a pseudocoelom and consist of both free-living and parasitic forms. The nematodes and the arthropods belong to a clade with a common ancestor, called Ecdysozoa. The name comes from the word ecdysis, which refers to the periodic shedding, or molting, of the exoskeleton.

What are five characteristics of phylum Annelida?

Characteristics of Annelida: Plesiomorphies and Other Features

• Symmetry and Size. Annelids are all bilaterally symmetrical animals.
• Coelom.
• Body wall.
• Parapodia.
• Nervous system.
• Sense organs.
• Circulation and respiratory structures.
• Segmental organs.

Is the oligochaete the same as a polychaete?

Some oligochaetes are easily confused with polychaetes, but oligochaete hooks are distinctive and are never hooded as in many polychaetes including the capitellid polychaetes which they most closely resemble. Oligochaetes are common in benthic samples, and are often dominant in organically enriched sediments if a sieve of 0.3 mm or less is used.

What are the three families of oligochaetes?

Most marine and freshwater oligochaetes belong to one of 3 families: Naididae, Enchytraeidae or Tubificidae. Some oligochaetes are easily confused with polychaetes, but oligochaete hooks are distinctive and are never hooded as in many polychaetes including the capitellid polychaetes which they most closely resemble.

Which is a characteristic feature of a polychaete?

Polychaetes are a subclass of the phylum Annelida that composes bristle worms. Importantly, the main characteristic feature of polychaetes is the presence of many bristles in parapodia. That is; each parapodium contains many bristles or chaetes made up of chitin.

What kind of digestive tract does an oligochaete have?

The digestive tract of oligochaetes is tubular and straight. 1. Mouth: The mouth opens into a muscular pharynx. 2. Pharynx: The pharyngeal muscles attach to the body wall.