Anal fin: a single fin located on the underside of of most sharks, behind the anus.
Barbels: Whisker-like sensory projections that extend from the nostrils in some sharks.
Dorsal fin: the famous, triangular fin most associated with sharks, located on the shark's back. Some sharks have just one and others have two, a larger anterior one and a smaller posterior one.
Dermal denticles: teeth-like growths on the shark's skin. These form different shapes in different species.
Nictating eyelid: an eyelid that closes to protect the eye at the moment of attacking prey
Oviphagy or oophagy: the fetuses obtain nourishment by feeding on unfertilized eggs or siblings
Oviparous: animals hatch from eggs outside the body Viviparity: animals hatch from eggs while still inside the female's body and are nourished via a placenta.
Ovoviviparous (Aplacental Viviparity): animals hatch from eggs that develop with no placenta while still inside the female's body.
Pectoral fin: a pair of fins just behind the gills.
Pelvic fins: a pair of fins on the underside of the shark between the pectoral and anal fin.
Spiracle: a gill slit found in some sharks behind the eyes providing oxygen directly to the eyes and brain.
Terminal mouth: Mouth that opens at front end of head with upper and lower jaws equal
