Marine Animals
The ocean covers approximately 71% of Earth's surface and is home to an enormous diversity of life — from microscopic zooplankton to the Blue whale, the largest animal ever known to have existed. Marine ecosystems include coral reefs, open ocean pelagic zones, kelp forests, mangroves, and the largely unexplored deep sea.
About This Section
Marine animal profiles on FaunaHub cover species from multiple taxonomic groups — including cetaceans (whales, dolphins, porpoises), cartilaginous fish (sharks, rays), bony fish, marine reptiles (sea turtles, marine iguanas), and selected invertebrates such as cephalopods. Each profile addresses habitat range, diet and feeding strategy, social behavior where applicable, and conservation status. Deep-sea species are noted where scientific knowledge is limited by the difficulty of direct observation.
Dolphin
Family Delphinidae — highly social marine mammals (Cetacea).
Shark
Cartilaginous fish — 500+ species in superorder Selachimorpha.
Whale
Cetaceans including the largest animals ever known to have lived.
Seal
Pinnipeds — marine mammals adapted to life in and out of water.
Octopus
Eight-armed cephalopod molluscs known for intelligence and camouflage.
Squid
Fast-swimming cephalopods — a group-level overview of order Teuthida.
Crab
True crabs (Brachyura) — ten-legged crustaceans with a broad shell.
Lobster
Clawed seabed crustaceans, using the American lobster as a reference.
Jellyfish
Soft-bodied drifting cnidarians with stinging tentacles.
Sea Turtle
Ancient ocean reptiles — seven species, several of them threatened.
Starfish
Sea stars (Asteroidea) — five-armed echinoderms of the seabed.
Clownfish
Reef anemonefish — see the Fish encyclopedia for more ocean fish.
Seahorse
Upright reef fish where the male carries the young.
Ray
Flattened cartilaginous fish related to sharks.
Fish Encyclopedia
Salmon, tuna, eels, pufferfish, and aquarium fish — the full fish category.
Orca (Killer Whale)
Orcinus orca — the ocean's apex predator and largest member of the dolphin family.
Common Dolphin
Delphinus delphis — fast, acrobatic dolphin of huge, highly social pods.
Spinner Dolphin
Stenella longirostris — famous for spinning leaps and day-night rhythms.
Pilot Whale
Globicephala — a large, deep-diving dolphin with exceptionally strong social bonds.
Risso's Dolphin
Grampus griseus — robust, scarred grey dolphin that hunts squid in deep water.
Commerson's Dolphin
Cephalorhynchus commersonii — tiny black-and-white "panda dolphin" of cold southern seas.
Great White Shark
Carcharodon carcharias — the largest predatory fish and an ocean apex predator.
Hammerhead Shark
Sphyrnidae — sharks with a wide, sensory-packed hammer-shaped head.
Giant Isopod
Bathynomus — a large deep-sea crustacean and seafloor scavenger.
Dumbo Octopus
Grimpoteuthis — among the deepest-living octopuses, with ear-like fins.
Giant Squid
Architeuthis dux — one of the largest invertebrates, of the deep ocean.
Anglerfish
Deep-sea predators that lure prey with a glowing, bacteria-powered light.
Frilled Shark
Chlamydoselachus anguineus — a rare, eel-like deep-sea "living fossil" shark.
Coelacanth
Latimeria — a lobe-finned "living fossil" found alive in 1938.
Nautilus
Nautilus pompilius — a shelled cephalopod and living-fossil mollusc.
Sea Urchin
Echinoidea — spiny echinoderms that graze the seabed.
Coral
Anthozoa — colonial cnidarian animals whose polyps build reefs.
Brain Coral
Diploria — boulder-shaped stony coral with a maze-like surface.
Staghorn Coral
Acropora cervicornis — fast-growing branching coral; critically endangered.
Elkhorn Coral
Acropora palmata — reef-crest builder with broad branches; critically endangered.
Sea Fan
Gorgonians — flexible, fan-shaped soft corals that filter-feed.
Mushroom Coral
Fungia — solitary, often free-living corals that can right themselves.
Sea Anemone
Actiniaria — soft coral relatives whose tentacles shelter clownfish.
Shrimp
Decapod crustaceans, from reef cleaner shrimp to deep-sea species.
Barnacle
Cirripedia — sessile crustaceans that filter-feed from inside a shell.
Cuttlefish
Sepiida — intelligent cephalopods that change colour in an instant.
Nudibranch
Nudibranchia — dazzling shell-less sea slugs with borrowed defences.
Krill
Euphausiacea — swarming shrimp-like crustaceans that feed much of the ocean.
Walrus
Odobenus rosmarus — a huge, tusked Arctic pinniped that dives for clams.
Mantis Shrimp
Order Stomatopoda — reef crustaceans with a super-fast strike and complex eyes.
Horseshoe Crab
Family Limulidae — ancient 'living fossil' arthropods with medically vital blue blood.
Hermit Crab
Superfamily Paguroidea — soft-bellied crustaceans that live in borrowed snail shells.
Sea Cucumber
Class Holothuroidea — soft seabed echinoderms and important ocean-floor recyclers.
Comb Jelly
Phylum Ctenophora — shimmering, non-stinging ocean drifters that swim with rows of combs.
Coconut Crab
Birgus latro — the largest land arthropod, a tree-climbing island hermit-crab relative.
Sea Squirt
Class Ascidiacea — sac-like filter feeders and surprising close kin of vertebrates.
Fiddler Crab
Genus Uca — mudflat and mangrove crabs whose males wave one enormous claw to court.
Sea Spider
Class Pycnogonida — bizarre marine arthropods, almost all legs, that digest through their limbs.
Salp
Class Thaliacea — jet-propelled gelatinous drifters that form living chains; tunicate kin of vertebrates.
Amphipod
Order Amphipoda — tiny sideways-flattened crustaceans (sandhoppers, scuds) vital to aquatic food webs.
Ribbon Worm
Phylum Nemertea — soft marine worms that fire out a hunting proboscis; the bootlace worm may be Earth's longest animal.
Lancelet
Genus Branchiostoma — a small, fish-shaped marine chordate (not a fish or vertebrate) that hints at vertebrate origins.
Animal Encyclopedia
Browse all animal categories including mammals, birds, reptiles, and insects.
Marine Conservation Context
Many marine species face significant conservation pressures including overfishing, bycatch, habitat destruction, ocean warming, acidification from increased atmospheric CO2, and plastic pollution. Conservation status information in these profiles is drawn from the IUCN Red List. Where a species' status is listed as Data Deficient or Not Evaluated, this is clearly stated rather than an estimate provided.