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

Phylum Annelida

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, Amphitrite

Class Oligochaeta (ol-e-go-key-ta)• Lumbricus, Tubifex

Class Hirudinea (hi-ru-din-e-a)• Hirudo, leech

• Earthworm dissection

Click on any term that is underlined to go to that slide

Nereis (clam worm)

Nereis

Nereis

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Aphrodite (sea mouse)

ventral

dorsal

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Other Polychaetes

Chaetopterus

Arenicola (Lug worm)

Amphitrite (plum worm)

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Hirudo (leech)Return to taxonomy

Lumbricus

Lumbricus

dorsal

ventral

clitellium

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Earthworm DissectionReturn to taxonomy

Cross section

Earthworm cross sectionReturn to taxonomy