What are the general characteristics of annelids?
Characteristics of Phylum Annelida They have a long and segmented body. Annelids are bilaterally symmetrical. They are triploblastic. Also, they exhibit organ system grade of organisation, showing organ differentiation.
Which characteristic is unique to polychaete annelids?
Unique among annelids, most polychaete body segments bear a pair of parapodia (flat, lobelike outgrowths) with setae, or tiny bristles.
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.
Are polychaete worms decomposers?
The decomposers are the polychaete worm and the queen conch.
What are three unique characteristics of earthworms?
An earthworm has a streamlined body with no antennae or fins or arms or legs! This streamlined shape is an adaptation to living in narrow burrows underground and the need to move easily through the soil. An earthworm has circular muscles that surround each body segment.
What are the characteristics of Annelida?
Characteristics of Annelida The characteristics of the organisms present in the Phylum Annelida are as follows: The Annelids are coelomate and triploblastic. They exhibit organ system level organization.
How are annelids bilaterally symmetrical?
Annelids are all bilaterally symmetrical, with elongated cylindrical bodies separated both outwardly and internally by a regular, linear succession of segments. Annelids have three distinct body sections. The majority of the body is made up of repetitive units known as segments.
What are the characteristics of Archiannelida?
ARCHIANNELIDA • Exclusively marine forms. • Body elongated and worm-like. • Setae and parapodia are usually absent. • External segmentation is slightly marked by faint, while internal segmentation is marked by coelomic septa. • Prostomium bearstwo or threetentacles.
What is the habitat of Annelida?
Annelids are found in terrestrial, marine and freshwater habitats but presence of water or humidity in terrestrial habitats is a very important factor for their survival. The Phylum Annelida consists of earthworm, polychaete worms and leeches. They are also known as segmented worms because they show metameric segmentation.