Phylum Annelida

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

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

Systems (continue) ExcretoryExcretory- a pair of nephridia per segment. RespiratoryRespiratory -through skin, some through parapodia; tubeworms have gills. CirculatoryCirculatory- closed system, use hemoglobin as oxygen carrier. NervousNervous- dorsal brain; ventral, double, solid nerve cord, with ganglia in each segment. EndocrineEndocrine- hormones secreted by nervous system. ReproductiveReproductive-  Dioecious (Separate Sexes) Male and Female in Polychaeta; no special organs, posterior end becomes gonads.  Monoecious (Contains both Eggs and Sperm) in Oligochaeta and Hirudinea; Clitellium.

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

Nereis (clam worm) Nereis Return to taxonomy

Aphrodite (sea mouse) ventral dorsal Return to taxonomy

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

Hirudo (leech) Return to taxonomy

Lumbricus dorsal ventral clitellium Return to taxonomy

Earthworm Dissection Return to taxonomy Cross section

Earthworm cross section Return to taxonomy