“Sharkology” 223shark species. A great deal of what we know about the anatomy, biochem-
istry, parasites, food habits, age and growth, and reproductive biology of
sharks—in short, everything but their behavior and ecology—is acquired
through dissection of dead offshore and inshore species caught commer-
cially or by biologists. Tolerance of captivity is another important attribute
of the sharks we know best. As a result, we know the most about abundant,
commercially important species and small, slow-moving species from shal-
low nearshore habitats. Among larger species, those that do well in large
public aquariums are better known, although we always have to be careful
about drawing conclusions from animals whose behavior has been altered
by being kept captive.
Putting things together, a list of best-known sharks would include
Whale, Nurse, Sandtiger, Shortfin Mako, Porbeagle, Basking, Common
and Bigeye threshers, Smallspotted Catshark, Smooth Dogfish, Leopard,
Silky, Bull, Blacktip, Blacktip Reef, Dusky, Sandbar, Tiger, Lemon, sev-
eral sharpnose sharks (Rhizoprionodon spp., especially terraenovae), Whitetip
Reef, Bonnethead, Scalloped Hammerhead, Great Hammerhead, and both
Spiny Dogfishes. The better-known rays include Atlantic Stingray, mantas,
Cownose and Bat rays, Round Stingray, Thorny Skate, Barndoor Skate,
Little Skate, Winter Skate, and Thornback Skate.Which species are least known?
Flip the lists above, and you have the answer. Large, deepwater, offshore,
and rare species; active species intolerant of captivity; and most freshwater
species are poorly known (except for what has been learned from dissec-Leopard Sharks are medium-sized animals (up to 1. 5 – 1. 8 m, or 4. 9 – 5. 9 ft) that frequent shallow waters from Oregon
to northern Mexico. Their biology is well known. They feed on a variety of crabs, clams, and small fishes and adapt
well to captivity. Photo by Matthew Field, http://www.photography.mattfield.com, Wikimedia Commons, http://en.wikipedia.org/wiki/File:Leopard
_shark_in_kelp.jpg