CRAYFISH

Place a paper towel in the dissection tray to make cleanup easier. Next obtain a crayfish specimen and examine its features. Be sure to locate all the items in bold print.

EXTERNAL:

Identify the cephalothorax, the abdomen, the carapace, the antennae, the antennules, the chelipeds, the walking legs, the maxillipeds, the maxillae, the mandibles, and the swimmerets. Check the first pair of swimmerets to see if they are soft (on females) or stiff (on males).

Remove the antennae, antennules, chelipeds, walking legs, maxillipeds, maxillae, and mandibles. Place them on a sheet of paper and label them.

INTERNAL:

Use the scissors to remove the carapace. Notice the soft feather gills on both sides of the cephalothorax. Carefully open the rest of the cephalothorax to expose the heart. Notice the small pores in the heart called ostia.

Next find the stomach and the digestive glands. Locate the intestine which passes under the exoskeleton covering the abdomen. Look on the ventral side of the abdomen and find the ventral nerve cord.

Clean up your table and label the diagram below.