Transcript Earthworms
ANNELIDA…The EARTHWORM! Phylum Class Family Genus Species - Annelida - Oligochaeta - Lumbricidae - Lumbricus - terrestris Part Function System Prostromium Digs dirt Digestive Mouth Food enters here Digestive Brain Sends/receives nerve messages Nervous Pushes food along Digestive Brings food to intestine Digestive Pumps blood Circulatory Pharynx Esophagus Hearts Seminal receptacle Holds sperm from another Reproductive worm Reproductive Seminal vesicles Makes sperm Part Function System Crop Stores food Digestive Gizzard Grinding food Digestive Filters blood (wastes) Circulatory Kidney Ventral Blood Vessel Absorbs food into blood Digestive (long) Circulatory Brings blood forward Circulatory Blood to posterior Ventral Nerve Connects brain to body Nervous Clitellum Band making slime to hold eggs Reproductive Ovaries Make eggs Reproductive Intestine Dorsal Blood Vessel Part Function System Setae Bristles for hold in burrow Movement Cuticle Skin-used to breathe (water) Respiration Nephridium Removes Liquid Waste Excretory Sugar maple forest before earthworm invasion After earthworm invasion http://www.nrri.umn.edu/worms/forest/index.html 3 ecological groups of earthworms Endogeic example: Aporrectode a caliginosa (angle worms) Epigeic example: Lumbricus rubellus (leaf worms) Anecic : Lumbricus terrestris nightcrawlers Body Structure: Coelom 7 Digestive System 8 Phylum Annelida Circulatory System 10 Continuous network of vessels; 5 muscular aortic arches Dorsal blood-Aortic Arches-Ventral blood Blood contains hemoglobin, which increases oxygen carrying ability Phylum Annelida Excretory & Nervous System Nervous system 12 Phylum Annelida Reproduction • Hermaphrodites • Eggs are produced when two earthworms inseminate each other during mating. • There are two male openings, and two pairs of small sacs, the sperm receptacles. During mating, these receive sperm from the other partner. • The eggs, formed in a pair of ovaries, are released from the oviducts into one of two Phylum Annelida 13 tiny pores Reproduction continued • Fertilization can be internal or external • Breeding is usually seasonal (spring or fall) • Mating occurs usually when the ground is wet following rain. Earthworms may emerge and travel over the surface of the ground before they mate Reproduction continued…. • The two worms join the lower surfaces of their anterior ends, with heads pointing in opposite directions. Mucous is secreted until each worm is enclosed in a tube of slime. • The worms then separate and egg-laying and fertilization occur later. • Egg-laying starts when the gland cells of the clitellum secrete a mucous ring that is moved forward over the body of the worm Reproduction continued…. A Worm is Born • Egg cocoons are deposited in the soil. • The fertilized eggs develop directly into young worms, which then escape through the egg membrane and an Annelid is born! Worm Anatomy External Anatomy: Internal Anatomy Please have your Earthworm colorfun and lab on your desk EXTERNAL Dorsal Anterior Mouth Ventral Posterior Clitellum Setae INTERNAL Pharynx Esophagus Crop Gizzard Intestine Dorsal BV Aortic arches Ventral BV Seminal vesicles Ventral nerve cord Review your colorfun and be ready to dissect tomorrow!