In the open waters of the Pacific and Indian Oceans, adult sevengill sharks (Notorynchus cepedianus) have been reported to feed on mackerel, chimeras, and small sharks. Along the coast of California, a hungry sevengill might thrash though shallow waters and attack a leopard shark.
Have you ever observed the feeding of the sevengill sharks? Long bamboo poles with clips on the end are used to dangle salmon or mackerel filets in front of the sharks. It may take as long as 30 minutes to feed them a tray full of filets. The leopard sharks often steal the show - and sometimes the food right from a sevengill's jaws!
The feeding (show) of the sevengill sharks definitely needed some spice, and in September 1987, it was decided to add Salt and Pepper to the calm waters of the Monterey Bay exhibit. Two years later, Salt and Pepper (a pair of female sevengill sharks) are doing well. Aquarist Gilbert Van Dykhuizen estimated the shark pup to be about 6 months old when they were put into the exhibit (they would be about two-and-a-half years old now).
There are presently six sevengill sharks in the Monterey Bay Exhibit. the names and weights of each are listed in the table below. How much do the sevengill sharks eat? Would you believe that the total recorded amount of food for all six sharks for all of 1988 was a mere 467 pounds and that the food bill was only $ 1500? (according to an estimate provided by Peter Ferrante.)
We have been told that a sea otter (warm-blooded animal) in its natural habitat eats about 25% of its body weight in food per day. For the adult sevengill shark, Blackie (a cold-blooded animal), the corresponding value is a mere 0.3%. As expected the growing juveniles and pups require 2-3 times as much. In the cold water of the Monterey Bay Exhibit no sevengill shark really works up an appetite. No wonder one or two feedings per week are sufficient.
Name Amount Fed Weight Amt/Day as % of in 1988 in Sept.'88 bodyweight in Sept.'88 ------------------------------------------------------------------------------- Blackie 120 lbs. 112 lbs. 0.29% Jackie 129 45 0.79 Jerome 94 41 0.63 Junior 56 20 0.77 Salt 44 14 0.86 Pepper 24 7 0.94
Appeared Oct.1989. Added to home page : Jan. 01, 1996. HFM