Shark Glossary

A plain-language glossary for recurring shark anatomy, habitat, and field-guide terms. The aim is simple: make the specialist words readable enough that the species pages stay calm and clear.

Plain language Anatomy and habitat terms Species examples

Common terms in the guide

Term	Meaning	Examples in this guide
Benthic	Living on or very close to the seafloor.	Spotted wobbegong, nurse shark
Pelagic	Living in the open water column rather than on the bottom.	Blue shark, oceanic whitetip, shortfin mako
Demersal	Associated with the seabed, often just above it.	Angel shark, many catsharks
Cephalofoil	The hammer-shaped head of hammerhead sharks.	Bonnethead, great hammerhead, scalloped hammerhead
Countershading	Dark above and pale below, a common camouflage pattern in open water.	Great white, porbeagle, shortfin mako
Filter feeder	An animal that strains tiny prey from the water.	Whale shark, basking shark
Photophores	Light-producing organs used by some deep-sea fishes and sharks.	Dwarf lanternshark
Nictitating eyelid	A protective lower eyelid found in many requiem sharks.	Bull shark, blacktip shark, blacknose shark
Caudal fin	The tail fin.	Pelagic thresher and common thresher show how extreme the upper lobe can become.
Rostrum	The front part of the snout.	Goblin shark
Estuary	A coastal zone where river and sea water mix.	Bull shark, bonnethead, blacktip shark
Shelf edge	The outer part of the continental shelf before the slope drops away.	Porbeagle, shortfin mako, deep-sea sharks more broadly