Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Giant squid
Name: Tom F Ihde
Location: N/A
Country: N/A
Date: N/A 

At what depth are giant squid normally found? If this is in the aphotic zone, what purpose does the ink sac serve? Have these squid been observed by man alive?

1) Giant squid are normally found from 300-600 meters deep, but there are documented sightings down to approx. 1175 m.
2) Good question! Yes, this is the aphotic zone, however, the term "aphotic" refers to the fact that there is not enough light for plants to grow, not necessarily that there is no light. So, there could very well be enough light for the squids ink to function as a "dummy" or decoy to confuse the predator, or as a "smoke screen" allowing the squid to escape. It is also possible that the squid's ink could function to protect the animal without being it turns out, the ink is very alkaloid, (it has a high pH) which may function to anesthetize the predator's sense of smell!
There is also the possibility that the giant squid don't even have an ink sac, which is often the case with deep-dwelling squid.
3) These animals have indeed been seen and captured while alive, though little is known about their natural behavior (as far as I know)

Tom F Ihde

Click here to return to the Biology Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (, or at Argonne's Educational Programs

Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory