Monday, September 12, 2011

Red Devils: The Humboldt or Jumbo Squid (dosidicus gigas)


There are many fascinating creatures in the ocean, but we seem particularly interested in two groups:  creatures we can eat, and creatures that may eat us.  We love to eat fish, but the only sharks we want to see are the ones on television.

People in California and up the western coast of the United States are becoming aware of a new predator, the Humboldt Squid, also known as the Jumbo Squid.  Scientists speculate that warming Pacific waters have allowed these squids to move up the coast from the Sea of Cortez off Mexico, up to California and even as far as Alaska.  A second explanation is that a reduction in sharks in that area has allowed competing predators such as the Humboldt to fill in the territory.  This is similar to the situation where a declining wolf population is replaced by coyotes.

Whatever the reason, the Humboldt is an amazing creature.  They grow up to 2 yards (2 meters) in length, and can weigh 100 pounds (45 kilograms).  They travel is groups, sometimes as many as 1,000 animals, and use their powerful arms and sharp beaks to hunt.  Humboldts are one of the faster swimmers in the ocean, and can squirt ink as a defense like an octopus. 

Because of chromatophore cells in their skin, they can create bright flashes to communicate with other squid.  They can also change their skin to a red color that makes it hard for other sea creatures to spot them in deep water.  In tribute to their color and fierce nature, Mexican fishermen call them 'diablos rojos' or 'red devils.'  The common name Humboldt derives from the Humboldt Current off South America, where these squid are usually found.

Humboldts are opportunistic eaters (much like humans), but in their home waters they eat lanternfish, mackerel, sardines, shrimp, mollusk and other squid.  Although I haven't read any accounts of Humboldt killing humans, I did see a diver on Animal Planet tell how a group of these squid attacked him and drug him down through the water.  Also, diver Howard Hall filming off Mexico has an interesting story about these aggressive animals tearing pieces of equipment from another diver during a night expedition. 

Professor Kelly Benoit-Bird of Oregon State University noted, "The Humboldt squid is a voracious predator that will eat anything it can get its tentacles on.  We put a pair of 10-pound squid into a tank and one immediately beheaded the other."

If Humboldts continue to move up the coast of the U.S., we may see more interaction between humans and these squid.  It will also be interesting to see the response from creatures that eat these squid, such as sperm whales, sharks, marlin, swordfish, porpoises and fur seals.  And if you're diving off Mexico or California and see flashing lights, be careful.

(This article in marinebio.org was very helpful.  As was this article about Professor Benoit-Bird's study of sonar and squid.  This article recounts Howard Hall's encounter with these creatures.  And the picture is from:  guardian.co.uk)

2 comments:

  1. Are the Humboldt squid edible? If so, I'll have the calamari.

    ReplyDelete
  2. Yes, they are edible. Fishermen in Mexico catch them when shrimp are not in season, and the Humboldts are processed and sold canned.

    ReplyDelete