catsharkHere, in the ocean primeval—well, one of Shedd’s original saltwater galleries—live two species of catshark, family Scyliorhinidae.

One is known as a dogfish, and the other barks like a dog.

Chain dogfish (and interchangeably, chain catshark) perfectly describes this little shark’s stunning pattern of dark brown links on a pale gold background. Look for three in the habitat. The largest—about 15 inches long—is the female. “We’ve had these since about 2003,” Ernie says. “When they came in, they were about the length of a cigarette.” The sharks are fully grown now.

These are bottom-dwellers of the deeper coastal waters of the western Atlantic, from New England to Florida and around into the Gulf of Mexico and Caribbean. They hug the rough outer continental shelf. At Shedd, you might see the chain dogfish vertical on the habitat’s rock walls. Like the draughtsboards, they can sit motionless for hours except for the rhythmic pumping of their gills.

Because they tend to live so deep, they are seldom seen even by divers. A biologist using a submarine for deep-sea research in the Gulf of Mexico encountered a chain dogfish at more than 1,800 feet. That was not surprising, but the shark’s fluorescent glow in the sub’s blue lights was a spellbinding discovery. The purpose of the fluorescence is still a mystery.

New Zealand’s draughtsboard shark is named for its blotchy checkerboard pattern. (Checkers are called draughts—pronounced “drafts”—in British parlance.) At Shedd, look for the 3-foot male hunkered down on the bottom of his habitat, snugged up against the glass and rockwork.

“These sharks spend most of their daytime hours lounging in caves or under ledges on the reef,” says senior aquarist Ernie Sawyer, who is collection manager of the Oceans gallery. “Then they come out at night to feed.” A draughtsboard will eat just about anything that fits in its capacious mouth, including an assortment of fishes and octopus, crabs and lobsters. “This species has a really big mouth and can swallow really big things,” Ernie continues, although that would not include the sprawling rock lobster that shares the exhibit.

This shark also has gorgeous molten-gold eyes flecked with black.

But most noteworthy is its habit, when threatened, of inflating its body to balloonlike proportions to avoid being eaten. Usually it fills up with water, but if the fish is taken by people and brought to the surface, it gulps air to inflate. This happened when Ernie was moving the shark from one exhibit to another. The aquarist held him mouth up until the fish eventually deflated with an explosive belching bark. But this harmless catshark is all bark and no bite.

Posted by Karen Furnweger, web editor