70 likes | 92 Views
Annelida, with 15,000 species, are bilaterally symmetrical coelomates inhabiting various environments. Their coelomes are divided by septa, with a complex digestive system and closed circulatory system. Hermaphroditic, they reproduce sexually and asexually through regeneration. The phylum comprised of three classes: Oligochaeta (earthworms), Polychaeta, and Hirudinea (leeches).
E N D
Phylum Annelida(Segmented Worms) 15,000 Annelid species Bilaterally symmetrical coelomates Coelomes divided into partitions by septa Inhabit marine, fresh water, & moist environments Has complex digestive system Has closed circulatory system Epidermis is primary gas exchange organ Are hermaphroditic Reproduce sexually by cross fertilization Reproduce asexually through regeneration 3 Classes
Class Oligochaeta • Include earthworms • Extracts nutrients from soils • Extremely beneficial to farming as they enrich and aerate soils
The Earthworm Giant Earthworm – Amazon Basin
Class Polychaeta • Very similar to oligochaeta • Most are marine • Have paddle or ridge-like extensions on segments called parapodia • Aid in gas exchange and locomotion
Class Hirudinea (leeches) • Most inhabit fresh water, or moist terrestrial environments • Feed on small invertebrates or are parasitic • Have significant medicinal value in treating bruising, and as a source of Pharmaceuticals