ExpertOceans & Marine Life
Expert ocean quiz: hadal zone, marine snow, nautilus and gyres
The only living shelled cephalopod, the zone below 6,000 m, cleaner-fish relationships, the Pacific garbage patch and marine snow. Expert oceanography.
Oceans & Marine Life quizzes
Marine fauna and flora, reefs, deep sea
The Oceans & Marine Life theme dives into the waters that cover most of the planet. It looks at the great oceans and their currents, coral reefs, mangroves, deep ocean trenches and the animals that live in them: whales, sharks, sea turtles, octopuses, jellyfish and fish adapted to the dark depths.
Oceans & Marine Life questions also touch on marine food chains, plankton, tides and the threats facing sea life, such as plastic pollution and coral bleaching. The quizzes are free: five difficulty levels from very easy to expert, and an explanation after every answer so you learn as you play.
Quizzes
Hard marine biology quiz: hydrothermal vents, echinoderms, sharks
What fuels life around hydrothermal vents, the phylum of starfish, the sperm whale's prey, pinnipeds and shark electroreception. Hard, free, 10 questions.
MediumOceans & Marine Life
Intermediate ocean quiz: octopus hearts, Gulf Stream, coral bleaching
Octopus hearts, the current warming Western Europe, the cause of coral bleaching, the largest fish and a tool-using marine mammal. Intermediate, free.
Easy marine life quiz: coral reefs, jellyfish, whales and trenches
Who builds coral reefs, what a jellyfish has instead of a brain, how whales breathe, the blue whale's diet and the deepest trench. Easy, free.
Very easyOceans & Marine Life
Very easy ocean quiz: whales, octopuses, clownfish and dolphins
The largest ocean, the biggest animal on Earth, an octopus's arms, the clownfish's home and what a dolphin is. Very easy, free ocean quiz, 10 questions.
Related themes
Frequently asked questions about Oceans & Marine Life
Why is sea water salty?
Rain and rivers dissolve mineral salts from rocks on land and carry them to the sea, where evaporation removes water but leaves the salts behind. Volcanoes and hydrothermal vents add more. Average ocean salinity is roughly 35 grams of salt per liter.
Are corals plants or animals?
Corals are animals. A reef is built by tiny polyps, related to sea anemones, that live in colonies and secrete a limestone skeleton. Many live in symbiosis with microscopic algae called zooxanthellae, which feed them through photosynthesis and give them their color.
Are whales fish or mammals?
Whales are marine mammals, part of the group called cetaceans. They breathe air through lungs and a blowhole on top of the head, are warm-blooded, give birth to live young and feed their calves with milk, just like other mammals.