Dive Dry with Dr. Bill

002: Sheephead

John Steinbeck wrote in The Log from the Sea of Cortez (undoubtedly paraphrasing his good friend the marine biologist Ed "Doc" Ricketts): "the best man fitted to observe animals, to understand them, emotionally as well as intellectually, would be a hungry and libidinous man, for he and the animals would have the same preoccupations." Perhaps that's why marine biologists tend to be interesting (and quirky) people.

The two male sheephead shown here are engaging in a territorial dispute over both food and potential mates. This particular ritual combat, observed last November, continued for several minutes until one forced the other to the bottom and nipped him as he swam away. Note the large canine teeth of these males (one reason I identify with them!).

Sheephead almost appear to be three different species. The juveniles tend to be bright red (although I've seen orange and yellow ones) with dark spots on their fins. Females are light pink with a white chin. The larger males have dark heads and tails with a pink or red mid-section.

All sheephead are born female, which makes it easy to identify the gender of the juveniles (try impressing your dive buddy by "guessing" the gender of each juvenile you see). These females mature at about four years and begin breeding. According to fish specialist (and humorist) Dr. Milton Love, most females change sex, turning into males starting at about eight years. The males may grow to three feet and live more than 50 years.

Sheephead are active during the day, but usually sleep in caves or crevices at night. Their strong jaws allow them to eat hard-shelled organisms like crabs, clams, mussels, snails and sea urchins as well as octopus and worms. In turn they may be eaten by harbor seals, sea lions and black sea bass. Native American middens on Catalina contain sheephead bones indicating they were caught with shell hooks or spears. European man initially did not favor sheephead, but gradually developed a liking for them too. They are now caught by fisherman, spear fishermen and even sold live in Asian markets.

© 2003 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 49, 10:00 AM and 5:00 PM weekdays.

Image caption: Male sheephead mouth fighting over territory

This document maintained by Dr. Bill Bushing.
Material © 2003 Star Thrower Educational Multimedia