Unit 6 Notes #4 CRUSTACEA

Name: ______Date: ______Unit 6 Notes #4 – ______CRUSTACEA : The Crayfish

A) Crustacea: - Crustaceans are primarily aquatic and range in size from the microscopic to the rather enormous (giant spider crab 5-6 meters)

- Common characteristics include ______exoskeleton, two

______and feeding mouthparts called ______

CRAYFISH B) ______Anatomy: -They inhabit freshwater streams and lakes.

-The thirteen segments in the ______to form the “______”

-The ______of the skeleton covering the anterior portion of the body is called the “______”

-Six most posterior segments form the______. Except for the

Last of these segments, each of these bears a pair of ______. The pair on the ______is important in determining the sex of the crayfish, this pair is ______

- Each pair of appendages (______) below the Carapace is slightly adapted or specialized to______. B) ______Anatomy: i)______: -Crayfish feed on insect larvae, worms, smaller crustaceans, small snails, fish and tadpoles. -After food is crushed and shredded by their mouth parts, it is passed into the

______

-A pair of ______just posterior to the stomach secretes enzymes into the ______. Then digested food passes down the intestine for absorption into the blood.

-Finally, undigested food passes out through the anus. The anus is found just under the______( ______

______)

ii) ______Systems

-Nervous system is much like that of the ______(ex – Earthworm) with a larger ______located just above the ______

-It connects to a pair of nerve cords (that appears as a single nerve cord) these nerve cords ______along the body to the______

-The brain is also connected to the ______

______-Each ______eye is supported at the end of a moveable stalk.

-______sensitive to touch are distributed over the body and appendages. ______

______

-At the base of the ______are______, which serve the sense of ______

-Antennules appear on the second segment of the head. These are organs of balance and hearing and touch.