Our shark glossary covers some of the terms used on this site that you may not have come across before.
Adelphophagy – Intrauterine cannibalism, the act of eating the siblings in the womb.
Ampullae of Lorenzini – These are tiny dents in the head and snout that detect electrical fields
Anal Fin – The fin on the underside of some sharks. Situated between the pelvic fins and the caudal fin.
Barbels – Long whisker-like organs found near the mouths of some species. They help to locate food in poor visibility.
Benthic – The seabed, or the bottom of a lake or stream. Benthic sharks are bottom dwellers.
Bioluminescence – Light produced by living organisms, including some sharks. eg. Lantern shark.
Branchial – Related to gills.
Caudal Fin – The tail fin.
Caudal Keel - A ridge found on the caudal peduncle of some sharks which provides stability during fast movement through the water.
Caudal Peduncle - The narrow part of the shark to which the tail fin is attached - the tail stalk.
Chondrichthyes – Cartilaginous fish.
Claspers – The two rolls of cartilage found near the pelvic fins of sexually mature male sharks. They serve to guide the sperm into the female’s cloaca during mating.
Cloaca – Opening for excretion of body waste and for reproduction.
Countershading - Having a lighter colour on the underside than on the upper side. This helps with camouflage from both above and below.
Dermal Denticles – Tiny tooth-like scales on the skin of a shark. Also called placoid scales.
Dorsal Fin – The fin(s) on the upper side of the shark. Some have only one while others have two.
Ectotherm – An animal whose body temperature is determined by its surroundings. Most sharks are ectothermic.
Elasmobranchii – The sub-class of the class Chondrichthyes that sharks, rays and skates belong to.
Endotherm – An animal able to generate its own body heat and maintain a constant temperature regardless of its surroundings.
Gill – The organ that allows aquatic animals extract oxygen dissolved in water.
Gill Slits - Most sharks have five gill slits on both sides of their heads from which water exits after being drawn in through the mouth and over the gills.
Gill Rakers – Stiff projections protruding from the gill arches of filter feeders that prevent tiny food particles passing through.
Heterocercal – A caudal fin with unequal sized lobes.
Homocercal – A caudal fin with equal sized lobes.
Inter-Dorsal Ridge - A ridge of skin between the first and second dorsal fins of some sharks
Lateral Line – A row of sense organs found down the side of the body that detect movement in the water.
Myomeres – Muscles found along the flanks which aid in swimming.
Osmoregulation – The control of water concentration in the body.
Oviparous – Egg laying animals where little or no embryonic development occurs inside the mother’s body.
Ovovivparous – The young develop in eggs and nourished by yolk, but the eggs are kept within the mother’s body until they’re ready to hatch.
Pectoral Fins – The pair of fins set low on the body and towards the front.
Pelagic – Relating to open water. Pelagic sharks are found in the open ocean.
Pelvic Fins – The pair of fins set low on, and to the rear of the body.
Placoid Scales - Also called dermal denticles. Small tooth-like scales on the skin of a shark
Plankton – Microscopic animals (zooplankton) and plants (phytoplankton) found floating in the marine environment and eaten by filter feeders.
Ram Filtration - A method of filter feeding where the shark swims forward with a wide open mouth to force water in and over the gills.
Ram Ventilation - A method of breathing where the shark must keep swimming forwards in order to keep oxygenated water flowing over the gills.
Rostrum - The long, saw-like snout of the saw sharks and sawfishes.
Spiracle – Opening behind the eye in some sharks which directs oxygen to the eye and brain, and aids water flow over the gills.
Squalene – Contained in the oil found in shark’s liver.
Teleost - Bony fish.
Tonic Immobility - A state of paralysis that can be induced by turning a shark on its back.
Viviparous – A reproduction mode where the embryo develops inside the mother’s body.
We will be adding to our shark glossary as the website grows.