How would you distinguish between oligochaetes and Hirudineans?

How would you distinguish between oligochaetes and Hirudineans?

Annelid worms—polychaetes, earthworms (oligochaetes), and leeches (hirudineans)—are distinguished by linear series of external ringlike segments; the grooves between segments coincide with internal compartments, often separated by transverse sheets of tissue (septa), containing serially repeated nervous, muscle, and …

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 head bears eyes, antennae, and sensory palps.

How do Hirudineans differ from polychaetes and oligochaetes?

4) Hirudineans are bisexuals, oligochaetes are bisexual and polychaetes are unisexual animals.

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.

What is the difference between polychaetes and oligochaetes?

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 polychaetes differ from polychaetes?

What are the 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 important structures used in polychaete identification?

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.

How do polychaetes reproduce?

Most polychaetes reproduce sexually, and the sexes are separate. Sex cells develop from masses of tissue in the metameres and leave by way of tubules or by rupture of the body wall. In most cases fertilization of the eggs by sperm occurs externally in seawater and results in the formation of free-swimming larvae.