Kingdom Animalia The most diverse of all the kingdoms!

Characteristics Heterotrophic All are Motile (locomotion) with the exception of the sponges which are sessile. Multi-cellular Reproduce Sexually Eukaryotic

The kingdom is divided into 2 basic groups : 1. invertebrates – no backbone 2. vertebrates – backbone present This kingdom contains numerous phylum’s. The biggest phylum is Arthropoda. The class Insecta are found in this phylum called Arthropoda.

The Earthworm Phylum: Annelida Lumbricus terrestris They possess a body cavity. They are segmented. Movement: possess Setae (small bristle- like spines located on each segment except first & last) which help grip the Soil.

Earthworm Digestion: Takes in soil & organic matter through its mouth. It then enters the pharynx, a muscular structure that pushes food down the esophagus which is a passage way between the pharynx & crop. The crop stores the food temporarily. It is then ground up in the gizzard. It then passes to the intestine (over 2/3 of body length) where digestion & absorption takes place. Soil particles & Undigested organic matter pass out through the anal slit.

Earthworm Reproduction Carry two sets of sexual organs, they are Hermaphrodites. They can’t fertilize themselves mating is still necessary. The Clitellum plays an important role in reproduction. Two worms approach each other nose to nose, bodies touching, they slide past each other until their heads are a bit past the clitellum. Both worms pass sperm through a Sperm Duct located between the head and the clitellum, into a temporary receptacle called Genital Setae in the other worm. The clitellum secretes a liquid that forms a flexible tube. As the tube lengthens, the worms back out of it. Soon the tube covers the front part of the worm. The worm lays a few eggs inside the tube, deposits some of the stored sperm, and withdraws from the tube, leaving the eggs and sperm inside the tube. The ends of the tube pinch off to form a Cocoon, and the whole thing shrinks to a tidy package about the size of a fat grain of rice. The cocoon is left alone sitting on or just under the surface of the soil. The worm continues to produce cocoons until the sperm is used up. Cocoons are durable, can overwinter in cold climates, and can wait out hot dry spells. After 3 weeks (ideal conditions) or longer the cocoon opens, and out comes the next generation.

Earthworm