Squid Dissection Lab

SQUID DISSECTION LAB Need: NO Gum/Food/Drinks, Hair pulled back out of face Groups of 4-5. Gather paper towels. Gather all needed materials Dissection, Scissors, Probe, Forceps Tray (tweezers) http://giantsquid.msstate.edu/LessonList/dissection.html Note: Make sure these materials are clean after your dissection lab today

SQUID DISSECTION LAB Once all materials are gathered then read the instructions carefully. Collect a squid from your teacher and follow all the procedures step by step. http://giantsquid.msstate.edu/LessonList/dissection.html

Procedures: (external anatomy) Place the squid with the ventral (front) side up. Measure the total length of the squid in centimeters. [record #1] Stretch out the tentacles and arms and count their number [record #2] Examine the tentacles and arms. Look at their differences. Where do the tentacles have the suction cups? Where does the arm? Why do you think there is a difference? Notice the body (main part) of the animal… do you see some spots (chromatophores)? What might be their function? [record #3] The body is mostly covered by the mantle (where you find its organs). It finally ends with the triangular flaps also known as fins. [record #4] Look at the eyes alongside the body. Then notice the siphon (water jet) on the collar of the squid? [record #5] 4. Used to pass food to the arms. 5. pen: vestigial organ from squid’s ancestors

Pages 701-7 Eye: Squid have a well developed eye that allows them to see as well as people! Arm: Have 8 arms with suction cups Fin: These help squid change direction when swimming Tentacle: Longer than the arms and have suction cups at the tip only Chromatophores: These spots change size to change the squid’s color for camouflage

Procedures: (internal anatomy) Pull the mantle up with the forceps where the siphon is, (it should be loose and easy to pull up).  Use scissors to carefully cut from the siphon to the fins.  Open the mantle to expose the structures inside. Locate the silvery black ink sac. What’s its function? [record #6] Remove an eye. Make a small cut in the center and find round obj. This obj. is the lens. [record #7] -answer first #8 With tweezers, locate the small, folded, plastic-like radula between beaks and remove it. What is the purpose of it? [record #8 (second one] Probe the mantle near the fins with your fingernail and find a hard obj. Grasp the obj. with forceps and gently pull out. (what is this? What is it for?) [record #9] 9. Release ink as a defense mechanism. Through the siphon.

Procedures: (internal anatomy) Locate the brain. (very highly developed for an invertebrate. Locate the stomach, white organ attached to esophagus at the end of the mouth. Locate the liver (beneath the ink sac). Locate the gonad (reproductive organ) near the far end of the mantle males= white/yellow color & females= clear color [record what gender was your squid on the bottom of the page] Locate the gills (feather like). Locate the heart (bulb at the end of gill). What color is the heart? [record]

8. Cutting the Mantle 9. Eyeball of Squid

11. Ink Sac 11. Writing with the Squid’s Pen…

17. Gills: 4. Suction cups