PYLUM ANNELIDA – segmented worms

Annelids Representative species – common earthwormRepresentative species – common earthworm Have a coelom – fluid filled body cavity surrounded by a mesoderm (room for organs)Have a coelom – fluid filled body cavity surrounded by a mesoderm (room for organs) Have a peritoneum (membrane in the coelom in which all organs are attached)Have a peritoneum (membrane in the coelom in which all organs are attached) Have 2 sets of muscle tissue. 1. body wall muscles – to move the worm and 2. digestive system muscles to move food through the systemHave 2 sets of muscle tissue. 1. body wall muscles – to move the worm and 2. digestive system muscles to move food through the system

Class Oligochaeta: Earthworms ``It may be doubted whether there are any other animals which have played so important a part in the history of the world as the earthworm.`` -Charles Darwin,

Class Oligochaeta: Earthworms 2500 species2500 species Many more cell layers than flat and round wormsMany more cell layers than flat and round worms Have blood to carry gases to and from body tissues (circulation)Have blood to carry gases to and from body tissues (circulation) Blood in earthworms contains a red protein hemoglobin (just like in us!)Blood in earthworms contains a red protein hemoglobin (just like in us!) Have 5 hearts near the anterior endHave 5 hearts near the anterior end

Earthworms cont… More complex digestive system than other worm phylaMore complex digestive system than other worm phyla They consume dirt (food and sand particles) via mouth, esophogus, pharynx, and then stores it in the crop.They consume dirt (food and sand particles) via mouth, esophogus, pharynx, and then stores it in the crop. After storage, food moves to the gizzard to be ground down, then to the intestine for digestion and absorption into the blood stream.After storage, food moves to the gizzard to be ground down, then to the intestine for digestion and absorption into the blood stream. Undigested food moves out the anusUndigested food moves out the anus

Earthworms cont… Setae are bristles that aid in mvmt.; each segment has 4 setae (except first and last ones)Setae are bristles that aid in mvmt.; each segment has 4 setae (except first and last ones) Complex NSComplex NS Reproduce sexuallyReproduce sexually HermaphroditesHermaphrodites

Other ANNELIDS Class Hirudinea – leeches (blood sucking parasites)Class Hirudinea – leeches (blood sucking parasites)

Class Polychaeta – marine worms

Worm Grunting/Charming