November 2003 Unknown

THIS MONTH'S WINNERS:

Many of our viewers submitted to last month's contest but this small cephalopod turned out to be a deceptively difficult identification. While all submissions recognized this animal as a member of the Class Cephalopoda, and several viewers identified our unknown as Sepia, the cuttlefish, no one submitted the corrrect genus, Rossia.

Please note: Prize winners are now drawn each month from the total pool of correct answers for that month.

Thanks to all of those who submitted an entry to this contest.

Good luck this month!

Octopus or Squid?

The class Cephalopoda includes a great diversity of Molluscs, often with complex anatomy (such as high resolving power eyes with lenses) and with complex behavior. Our November unknown, Rossia pacifica, the stubby squid, is a small cephalopod belonging to the Family Sepiolidae, a group which includes the cuttlefish. Although less than 6 centimeters in length, Rossia is a fairly successful cephalopod -- it is quite abundant across a range that extends from Southern California around the North Pacific to Japan. The stubby squid lives at depths that range from shallow waters down to 300 meters or more. We have collected them in dredges on muddy and sandy bottom sediments. We have kept specimens of Rossia for several weeks in cold saltwater aquariums at Bamfield Marine Station. They have also been kept at the Seattle Aquarium and the Vancouver Aquarium, where they are a great attraction as a contrast to the world's largest octopus, the Giant Pacific Octopus. Rossia reproduction is a terminal sort of thing -- at least for the adults. Both male and female die after mating. Before she dies, the female lays about 40 or so eggs, usually in a clam shell on the ocean floor. The eggs hatch after about five months and the new animals live for only two years before they mate, and die. Adult Rossia feed on shrimp, which are usually abundant on their ocean floor home.