Summary
Cartilaginous fishes with sensory adaptations, many of which are top predators.
In depth
Features: cartilage skeleton, electroreception via ampullae of Lorenzini, dermal denticles, and continuous tooth replacement. About a third of species are threatened, mainly by fishing.
Slow growth and late maturity make sharks vulnerable. Finning and bycatch drive declines. Shark roles in controlling prey populations support ecosystem balance.
Example: hammerheads sense electric fields to find prey buried in sand.
Sharks, rays and skates are cartilaginous fishes (Chondrichthyes) with skeletons of cartilage, skin covered by tooth-like denticles and, in sharks, continuously replaced teeth. They lack a swim bladder and rely on oily liver and swimming for buoyancy.
Senses are acute: ampullae of Lorenzini detect electric fields, the lateral line detects vibrations, and olfaction detects blood at tiny concentrations. Reproduction varies: eggs, live-bearing with a placenta or from egg yolk. Many species mature late and have few young, making them vulnerable to overfishing, with about a third threatened.
Example: the whale shark is the largest fish but feeds on plankton.
Frequently asked questions
What is Sharks and Rays?
Cartilaginous fishes with sensory adaptations, many of which are top predators.
Which area of biology covers Sharks and Rays, and how advanced is it?
Sharks and Rays is one of the 54 topics in Marine & Environmental Biology. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Marine Food Webs, Coral Reefs, Overfishing.
Why does Sharks and Rays matter?
Apex sharks keep ecosystems balanced.
Can you give an example of Sharks and Rays?
Whale sharks are filter feeders.
What should I learn before Sharks and Rays?
Sharks and Rays is a Beginner topic, so no earlier topic is required. Other Beginner topics in Marine & Environmental Biology that pair well with it include Oceans, Ocean Zones, Plankton.
What topics are related to Sharks and Rays?
The closest topics to Sharks and Rays are Marine Food Webs, Coral Reefs, Overfishing, Whales and Dolphins. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Sharks and Rays?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Sharks and Rays. To practise the whole of Marine & Environmental Biology, use the Marine & Environmental Biology quiz.
How is Sharks and Rays different from Marine Food Webs?
Sharks and Rays: Cartilaginous fishes with sensory adaptations, many of which are top predators. Marine Food Webs: Phytoplankton support zooplankton, fish and top predators, with energy lost at each level. Read both side by side and note what each one explains.
How should I study Sharks and Rays step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Marine Food Webs and explain the difference aloud. Finally, take the Marine & Environmental Biology quiz and come back to this page for any question you miss.