Crayfish Pre-lab Worksheet - Mr.E Science

Name: _______________________________ Date: ___________50 points possibleCrayfish Pre-lab WorksheetThe following worksheet must be successfully completed before you start the actual dissection of thecrayfish.Introduction1. What phylum does the Crayfish belong? __________________________________2. Name two common characteristics crayfish share w/ annelidsi. __________________________________________________________ii. __________________________________________________________3. Name three differences crayfish have w/ annelidsi. __________________________________________________________ii. __________________________________________________________iii. __________________________________________________________4. To cut away the hard exoskeleton properly, what two tools are recommended:i. _____________________________________External Featuresii. _____________________________________5. The body is divided into two parts. Name themi. ____________________________________ii. ____________________________________6. How many major limbs? __________________________________7. What are the pinchers called? _____________________________8. Identify these external features and describe their function/location:a. Cephalothorax __________________________________________________b. Cervical Groove __________________________________________________c. Abdomen __________________________________________________d. Swimmerets __________________________________________________e. Compound eye __________________________________________________f. Rostrum __________________________________________________g. Antenna __________________________________________________h. Antennule __________________________________________________i. Cheliped __________________________________________________j. Uroped __________________________________________________k. Telson __________________________________________________l. Walking legs __________________________________________________m. Maximilliped ______________________________________________

Name: _______________________________ Date: ___________50 points possibleInternal Features9. Identify these internal features and describe their location, appearance and function:a. Brain __________________________________________________b. Green gland __________________________________________________c. Ventral nerve cord__________________________________________________d. Cardiac stomach __________________________________________________e. Pyloric stomach __________________________________________________f. Intestine __________________________________________________g. Digestive gland __________________________________________________h. Ventral Nerve Cord _________________________________________________i. Gills __________________________________________________j. Anus __________________________________________________k. Bladder __________________________________________________Beginning the Dissection10. After placing the specimen in the dissecting pan, what do you do next?_______________________________________________________________________11. Describe the next cut you will do. _________________________________________________________________________________________________________________________12. When you remove this part of the cephalothorax, what is exposed? ____________________13. What is the chamber called that houses the gills? __________________________________14. Describe the water flow over the gills: __________________________________________15. With the crayfish on the tray, dorsal side up, name three organs that will be visible once thecarapace is removed?__________________, _________________, _________________16. Describe your next set of cuts: ___________________________________________________Natural History____________________________________________________________________________17. Crayfish are active after sunset and before sunrise. What form of activity is this?______________________18. What does the crayfish normally feed on? _________________________________________19. Where are the eggs stored in the female? __________________________________________20. How many eggs can normally be laid by the female? ________________________________