Crayfish Dissection

dissection of a crayfish

cephalothorax

anterior body tagma; a fused head and thorax

abdomen

posterior body tagma; segmented

carapace

hard exoskeleton over the cephalothorax that protects the internal organs

cervical groove

a line that divides the cephalothorax into a head region and thoracic region

rostrum

pointed appendage between the eyes that protects them

compound eyes

have many lenses and can see movement

antennae

feel a head of the crayfish

antennules

smell food, mates, and predators and detect motion in the water

uropods

outer portions of the fan-like tail; function as paddles during swimming

telson

inner portion of the fan-like tail; functions as a paddle during swimming

chelipeds

claws; used for protection and capturing prey

walking legs

walk and move water over the gills

swimmerets

tiny legs used for swimming

gonopods

enlarged pair of swimmerets no male crayfish that transfer sperm into the female

maxillipeds

help the crayfish manipulate food

maxillae

push food into the mouth

mandibles

food-crushing jaws

anus

eliminates waste

gills

site of gas exchange

heart

pumps hemolymph to the tissues

digestive gland

produces enzymes that help digestion

anterior gastric muscles

help the stomach digest food (front)

posterior gastric muscles

help the stomach digest food (back)

mandibular muscles

move the mandibles

stomach

breaks down food

intestine

absorbs nutrients

abdominal muscles

bend and straighten the abdomen

testes/ovaries

produce eggs or sperm

green glands

regulate salt and water balance in the crayfish

ventral nerve cords

carry messages between the brain and body