What are the two characteristics of polychaetes?
The known species of polychaetes share only a few characteristics. Each has a head, a tail and a segmented body, and typically each body segment has a pair of leg-like parapodia with spiny bristles sticking out. It’s these bristles that give the worms their name: “polychaete” is Greek for “with much hair.”
What are polychaetes and Oligochaetes?
Definition. Polychaetes refer to the marine annelids, with unsegmented swimming appendages with many chaetes. Meanwhile, oligochaetes refer to the hermaphroditic terrestrial or aquatic annelids that lack a specialized head.
What physical characteristics do all polychaetes have in common?
physical characteristics Body elongated and flattened with conspicuous parapodia with bristles. The head has four eyes, two antennae, and two palps. Has eversible pharynx; armed with chitinous teeth. Color is greenish during spawning season and varies from red to light brown at other times.
How do polychaetes help the environment?
But most importantly, he says, polychaetes may play a vital role in climate control by helping to reduce carbon dioxide in the atmosphere. On the ocean floor, polychaetes help convert organic debris into carbon dioxide, which is transported to the surface dissolved in water.
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 do polychaetes eat?
Carnivorous polychaetes may feed on prey or carrion, and mollusk, crustaceans, ophiuroids and polychaetes fragments are often consumed [27, 33, 55]. Cannibalism is also found for some species [8, 9].
Where can polychaetes be found?
the ocean
the bristleworms Of the approximately 9000 species of annelids, more than 8000 are polychaetes. These segmented worms are among the most common marine organisms, and can be found living in the depths of the ocean, floating free near the surface, or burrowing in the mud and sand of the beach.
What type of worms are polychaetes?
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 difference between leeches and polychaetes?
Polychaetes are the most diverse group of annelids and most live in the marine environment. They differ from earthworms and leeches in that they have appendages called parapodia and do not possess a clitellum. In size they range from 1 mm (0.04”) to 3 m (10′) but most are around 10 cm (4”).
How are polychaetes different 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.