08 Sept. 2014Annelida.ppt1 Phylum Annelida segmented worms 08 Sept. 2014Annelida.ppt2 Phylum Annelida Latin ringed analogy to tree annual rings ~ 9000 species Body plan Tube-in-tube, Protostomous Bilateral symmetry Coelomate, split coelom Marine, aquatic, terrestrial 08 Sept. 2014Annelida.ppt3 Phylum Annelida Tissues and organs differentiated Segmentation highly developed Mesodermal blocks, each with own coelom Septa between segments 08 Sept. 2014Annelida.ppt4 Phylum Annelida Hydrostatic skeleton Fluid pressure in coelom provides support & locomotion Circular muscles Longitudinal muscles Peristaltic locomotion 08 Sept. 2014Annelida.ppt5 Function of a hydrostatic skeleton 08 Sept. 2014Annelida.ppt6 Phylum Annelida Setae (bristles) of chitin anchors for earthworm paddles for polychaete Enlarged as jaws in leeches, some polychaetes 08 Sept. 2014Annelida.ppt7 Animal Life Ways the needs of cells are met Food O 2 and CO 2 exchange Across epidermis, some have gills Waste removal Metanephridia in each segment 08 Sept. 2014Annelida.ppt8 Phylum Annelida Special concerns of a multicellular animal Circulation closed Coordination: Nervous system with paired ventral cords Structural support: Hydrostatic Movement: Hydrostatic Maintenance of water balance: Segmental metanephridia. Reproduction Usually sexual, sexes separate or hermaphroditic 08 Sept. 2014Annelida.ppt9 Phylum Annelida Closed circulatory system Multiple hearts Hemoglobin not in blood cells reddish-pink color 08 Sept. 2014Annelida.ppt10 Phylum Annelida Central nervous system Dorsal brain Pair of nerves on sides of esophagus Paired ventral nerve cords with paired ganglia in each segment Transverse nerves connect ganglia in each segment 08 Sept. 2014Annelida.ppt11 Phylum Annelida Earthworms paired nerve cords are fused into single ventral cord Arthropod better illustrates primitive nervous system of both phyla. 08 Sept. 2014Annelida.ppt12 Phylum Annelida Metanephridia for excretion of metabolic waste products 08 Sept. 2014Annelida.ppt13 Phylum Annelida Class Polychaeta Mostly marine, very diverse (polyphyletic ) many setae, clusters with 20+ setae parapodia 08 Sept. 2014Annelida.ppt14 Phylum Annelida Superclass Errantia Mostly marine, diverse active swimmers, predators many setae, clusters with 20+ setae parapodia 08 Sept. 2014Annelida.ppt15 Phylum Annelida Superclass Sedentaria Mostly marine, sedentary tube builders, filter feeders Class (?) marine tube worms Class (?) Clitellata With clitellum 08 Sept. 2014Annelida.ppt16 Phylum Annelida Class (?) Clitellata Clitellum Aquatic & terrestrial Subclass (?) Oligochaeta Few setae in 2-4 clusters per segment 08 Sept. 2014Annelida.ppt17 Phylum Annelida Subclass (?) Hirudinea pair of bladelike jaws posterior suction cup Predators External parasites, bloodsuckers Secrete anticoagulants Medicinal use 08 Sept. 2014Annelida.ppt18 Phylum Annelida Class Hirudinea Hirudin from leech, Hirudo medicinalis, inhibits blood clotting H. medicinalis, registered as medical device.