Phylum Annelida

Phylum Annelida Characteristics Protostomia, eucoelomates Metamerism (= unspecialized segmentation) In the Classes: Parapodia Clitellium

Systems Integument- epidermis is one cell layer with mucous gland that secrete a moist cuticle. Skeletal -hydrostatic (using coelom) Muscle- longitudinal and circular muscles Each segments muscles are independent of the other segments. Digestive- complete, complex, with typhlosole for absorption and chloragogen cells acting as digestive gland and excretory cells.

Systems (continue) Excretory- a pair of nephridia per segment. Respiratory -through skin, some through parapodia; tubeworms have gills. Circulatory- closed system, use hemoglobin as oxygen carrier. Nervous- dorsal brain; ventral, double, solid nerve cord, with ganglia in each segment. Endocrine- hormones secreted by nervous system. Reproductive- Dioecious in Polychaeta; no special organs, posterior end becomes gonads. Monoecious in Oligochaeta and Hirudinea; Clitellium.

Annelida Taxonomy Phylum Annelida (an-nel-i-da) Earthworm dissection Click on any term that is underlined to go to that slide Phylum Annelida (an-nel-i-da) Class Polychaeta (poly-key-ta) Nereis, Aphrodita, Chaetopterus, Arenicola, Amphitrite Class Oligochaeta (ol-e-go-key-ta) Lumbricus, Tubifex Class Hirudinea (hi-ru-din-e-a) Hirudo, leech Earthworm dissection

Return to taxonomy Nereis (clam worm) Nereis Nereis

Return to taxonomy Aphrodite (sea mouse) dorsal ventral

Other Polychaetes Return to taxonomy Amphitrite (plum worm) Chaetopterus Arenicola (Lug worm)

Hirudo (leech) Return to taxonomy

Lumbricus Return to taxonomy dorsal ventral clitellium Lumbricus

Earthworm Dissection Return to taxonomy Cross section

Earthworm cross section Return to taxonomy Earthworm cross section