Are squid vicious?

A skiff captain, front, and his client display the catch of the day, a 3-foot, 40-pound Humboldt squid, during a fishing expedition in the Sea of Cortes.  (Jim Knowlton / For the Times)

Pete Thomas, left, and Rocio Lozano swim next to a Humboldt squid in the Sea of Cortes.  (Jim Knowlton / For the Times)

Pete Thomas, left, and Rocio Lozano inspect a large squid hooked in the deep waters of the Sea of Cortes.  (Jim Knowlton / For the Times)

Pete Thomas swims closer to a Humboldt squid in the Sea of Cortes.  (Jim Knowlton / For the Times)

A Humbolt squid caught in the Sea of Cortes. The jumbo squid can reach lengths of 7 feet and weigh as much as 100 pounds.  (Jim Knowlton / For the Times)

Deckmate Antonio Nunez of the dive boat Garota displays a Humbolt squid caught in a remote area southeast of La Paz.  (Pete Thomas / Los Angeles Times)

Underwater video captures the moves of a Humboldt squid.  (Scott Cassell / For the Times)

Long common off South America, the Humboldt squid began establishing themselves in the Gulf of California - better known as the Sea of Cortes.  (Scott Cassell / For the Times)

The torpedo-shaped Humboldt squid thrive at great depths and use a form of jet propulsion to squirt themselves quickly through their hazy realm.  (Scott Cassell / For the Times)

Humboldt squids are voracious animals with probing arms and tentacles lined with hundreds of gripping suckers and clasping hooks, and with beaks designed to tear off fist-sized hunks of flesh.  (Scott Cassell / For the Times)

The squid invasion could be a sign that one of the richest marine areas of the world is ailing.  (Jim Knowlton / For the Times)

A Humboldt squid is pulled out of the waters of the Sea of Cortes.  (Scott Cassell / For the Times)

Scott Cassell holds a Humboldt squid caught in the Sea of Cortes.  (Scott Cassell / For the Times)