All are predators. All are predators. They develop in the egg cocoon. All segments are equal. Sub Class I- Errantia. Inhabit moist soils, lack Parapodia, few setae (oligochaetes) or none (hirudinids), reduced head, gonads! The earthworm, well-liked for creating healthy soil for our earth, is perhaps the most recognizable creature in this group. anterior and posterior suckers, separate sexes, and setae.

belong to the smallest and most evolutionarily derived class of annelids.

Errantia and sedenteria, 1) Class Errantia- errant worms. What types of locomotion do various species of Errantia have?

Finally, class Polychaeta is the largest but probably the least familiar group of phylum Annelida. What is the reproductive individual of errantia called? The Class Polychaeta has been divided in to two subclasses. Are annelids acoelomate or do they have a true coelom?


Digestive tract- mouth, buccal cavity, pharynx.

D. are hermaphroditic.

What filters fluids to nephridia through a funnel-like structure with cilia? Class Errantia –Marine withparapodia Class Sedentaria –Marine, freshwater, terrestrial –Parapodes reducedor absent –Setaefor ancres BIO2135 –Animal Form and Function Metamerism Fig. No asexual reproduction. first segment and contains anterior structures. Is the clade Hirudinea monoecious or dioecious?

Characters: Body is divided into many segments, except head and anal segment. Errantia differ from other annelids because errantia have, The typical nervous system of annelids consists of. pair of parapodia with bristles. No distinct head. What is the dorsal fold of the intestine that increases surface area?

We have tutors online 24/7 who can help you get unstuck. Parapodium is with an endoskeleton known as aciculum. Fused double nerve cord. Earthworms and allies. Septa typically present. (A) Group I. Polychaeta errantia (Wan­dering polychaetes) [L. mantis = wandering]: Characters: (i) … Free living. But this subdivision is an artifi­cial, not a natural one.

Errant polychaetes include actively crawling or swimming forms which may, however, also spend time in burrows or crevices, or under rocks on the seashore.

The class has usually been divided on the basis of mode of existence into two groups, the errantia and the sedentaria.

Does the clade Hirudinea reproduce asexually or sexually, between longitudinal and circular muscles. The valves are connected to one another at a hinge. Dorsal and ventral vessels. Are most errantia dioecious or monoecious? 17 BIO2135 –Animal Form and Function Class Errantia Polychaeta (Poly = many, Chaeta = bristle) are the most diverse and most speciose group of the Annelida, containing over 5,500 species.. Bearded fireworm (Hermodice carunculata) from class polychaeta.

Class Errantia –Marine withparapodia Class Sedentaria –Marine, freshwater, terrestrial –Parapodes reducedor absent –Setaefor ancres BIO2135 –Animal Form and Function Metamerism Fig. What coordinates swimming and crawling in each segment? Which blood vessel is largest in Annelids? Errantia, occasionally Aciculata, is a subclass of polychaete worms. What is the prostomium? Has sperm. What are the various feeding styles of Errantia? Burrow into substrate. Respiration through skin. Extensive coelom. Most are vagile predators, others adopt a burrowing mode of life. Are most errantia dioecious or monoecious? Monoecious.

What are the excretory structures in annelids? Which blood vessel is near the nerve cord? The class has usually been divided on the basis of mode of existence into two groups, the errantia and the sedentaria.

Phylum ANNELIDA Annelids are vermiform, bilaterally symmetrical, triploblastic and schizocoelomate animals whose body is metamerically segmented and covered with a layer of cuticle. How many eyes do Errantians typically have (may be complex). 19. Dorsal vessel is the main pumping vessel. Most of them are free swimmers, some may live in the tube. Small prostomium. Burrow into substrate 2) Class Sedenteria- tube worms. Some typical leech characteristics are as follows: anterior and posterior suckers, a clitellum, no setae. Esophagus. Closed system. What type of circulatory system do annelids have? What is the non-reproductive individual of errantia called? Presence of mandible with teeth. Phylum Annelida- Subphylum Pleistoannelida-Class Errantia- Class Sedenteria- Order Clitellata- Family Lumbricidae- Family Hirudinidae, Marine worms. Most ancestral annelids. 2 nerve cords.

Characteristics. Free living. Filter feeders and secrete their own mucous tube

Errantia differ from other annelids because errantia have Hickman - Chapter 11 #20 21.

What does each segment have? Tend to show homonomy.

Characteristics.

Acron is divided into prostomium and peristomeum and the posterior terminal segment is called pygidium. Generally detritivores. Class Polychaeta. a brain, a ventral nerve cord, and a dorsal nerve cord. consist of active predators and sedentary particle feeders. Errantia (scaleworms, sea mice; phylum Annelida, class Polychaeta) A subclass of polychaete worms which have a large number of body segments, those of the head and posterior differing from the rest.The mouth often has several paired jaws. Clitellum secrets a mucous sleeve that slides as it corrects eggs and then sperm to form an egg cocoon. The Errantia A belong to the smallest and most evolutionarily derived class of, 1 out of 1 people found this document helpful. This page last updated 15 May 2019 by Udo M. Savalli (, Complete digestive tract with regional specialization, Closed circulatory system with respiratory pigments, Usually with lateral chaetae (spines) on each segment, Marine, fresh water, and terrestrial environments, Most have sensory tentacles and eyes on head, Mobile (errant): crawl over substrates or swim, The monophyly of this group is not certain, Parapodia and chaetae often reduced or lost, Most are sedentary, living in burrows or secreted tubes, Mostly filter feeders or suspension feeders, Polychaete worms that do not fit into the other groups, Parchment worms (Family Chaetopteridae) are perhaps the most basal of the annelid worms, Aelosomid worms were thought to be oligochaetes due to their fresh-water habits, but may be polychaetes instead, Presence of clitellum (forms muscus and egg cocoon), Mostly in terrestrial or fresh water environments, Segmenting less defined; body not divided by septa, Have a posterior sucker and usually also an anterior sucker, Mostly in fresh water, a few are marine and semi-terrestrial, May be scavengers, predators, or external parasites, Unsegmented (most likely secondarily lost), Muscular, non-retractable proboscis with a groove (gutter), Marine sediments: deposit or suspension feeders, Anterior introvert can be fully withdrawn.
Setae absent. What do the nerves do in the nervous system? Known for their long, segmented bodies, annelids, such as earthworms, leeches, and many marine worms, certainly have their place in the world. Few setae per segment.

Oral and caudal sucker. Anterior ocelli (photoreceptors) external breathing. What does the digestive tract of Errantia contain? So most of the re­searchers divide polychaeta into two groups. antagonistic action of longitudinal muscles. What can all species do in the Errantia class? first segment and contains anterior structures. Dont need to grind up blood. Is an annelids digestive system complete or incomplete? Polychaeta (Poly = many, Chaeta = bristle) are the most diverse and most speciose group of the Annelida, containing over 5,500 species.. Bearded fireworm (Hermodice carunculata) from class polychaeta. In this lesson, we will learn more about phylum Annelida and gain an …

1) Class Errantia- errant worms. The cocoon in the earthworm is produced by the.

Order of the class sedenteria. Longitudinal muscles. Where is the diffusion of gases typically in Errantia? Body bears segmentally arranged setae or chetae.