Shark Flashcards
Dermal Denticles (Placoid Scales)
Tough protective covering on skin that resemble tiny teeth. They have hydrodynamic properties that allow sharks to move with minimal water resistance
Nares
Consist of both incurrent and excurrent apertures, used in odor detection
Ampullae of Lorenzini
Specialized sensory cells that are capable of detecting weak electric fields at short ranges, enabling sharks to locate prey without visual or olfactory clues
Spiracle
A rudimentary first gill slit that may be highly reduce or absent in most fast moving sharks. It provides for oxygenated blood directly to the eye and brain via a separate blood vessel
Gill Slits
Exit for water that has passed through the gills after it has entered through the mouth
Claspers
Male copulatory organs
Lateral Line
A series of small fluid-filled canals lying just beneath the skin on the head and along the sides of the body. This complex system of receptors transforms underwater sound or mechanical disturbance into nerve impulses that allows a shark to orient to the source
Stomach
Three parts: Cranial, fundal, pyloric. Food storage and digestion
Pancreas
A flattened white gland that secretes digestive juices and insulin
Gall Bladder
A green sac that holds bile for enzymatic digestion
Intestine
Contains the spiral valve, which is an internally twisted or coiled organ that serves to increase the absorptive surface of the intestine
Liver
Bile secretion, glycogen and vitamin D storage. A large, soft, oily organ which occupies as much as 25% of the body cavity. The oil aids in buoyancy
Spleen
Maintenance of blood (destroys old RBC’s and makes new RBC’s)
Heart
Muscular S-shaped tube with 2 chambers for pumping blood throughout the body
Gill Lamellae
Feather-like portion of the gills responsible of gas exchange
