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Aquatic animals

Aquatic animals live in water or depend heavily on it for food, shelter or reproduction. Some live in the sea; others use rivers, lakes, marshes or wetlands.

Which animals live in or near water?

Examples include dolphins, whales, seals, walruses, crocodiles, alligators, otters, beavers, jellyfish, octopuses, crabs, sharks and other fish. These very different animals share adaptations for using aquatic environments.

A

alligator

AlligatorAlligator

Silvery asp with an elongated body and large mouth, seen from the side underwater

AspLeuciscus aspius

Atlantic salmon (Salmo salar) swimming in an aquarium

Atlantic salmonSalmo salar

B

Adult bald eagle with a white head, hooked yellow bill and dark brown plumage

Bald eagleHaliaeetus leucocephalus

beaver

BeaverCastor fiber; Castor canadensis

Large grey beluga sturgeon with a short snout, barbels and rows of bony plates swimming in blue water

Beluga sturgeonHuso huso

Beluga whale facing the camera underwater, showing its rounded forehead and pectoral flippers

Beluga whaleDelphinapterus leucas

Blue and red betta fish with long, spread fins in an aquarium

Betta fishBetta splendens

Flat, sand-coloured turbot with both eyes on its upper side lying on the seabed

Black Sea turbotScophthalmus maeoticus

blue whale

Blue whaleBalaenoptera musculus

bowhead whale

Bowhead whaleBalaena mysticetus

Dark grey Ancistrus with pale spots resting on gravel at the bottom of an aquarium

Bristlenose plecoAncistrus

Brown shrimp (Crangon crangon) with long antennae and a segmented abdomen

Brown shrimpCrangon crangon

Brown trout (Salmo trutta), showing its spotted body and body shape.

Brown troutSalmo trutta

C

Grey-olive caiman resting on a riverbank

CaimanCaimaninae

Capybara with brown fur and a broad muzzle

CapybaraHydrochoerus hydrochaeris

Common barbel with an elongated snout and mouth barbels swimming near the bottom

Common barbelBarbus barbus

Silvery common bream showing its deep, laterally flattened body underwater

Common breamAbramis brama

Common carp showing its large scales and barbels beside the mouth

Common carpCyprinus carpio

A common clownfish with an orange body, three white bars and a rounded tail beside an anemone

Common clownfishAmphiprion ocellaris

Common moorhen with a red forehead, yellow-tipped bill and long green toes

Common moorhenGallinula chloropus

Silvery common roach with an orange-red iris and reddish lower fins

Common roachRutilus rutilus

Common toad with warty skin and copper eyes sitting on a rock

Common toadBufo bufo

Corydoras catfish with a dark white-spotted body and orange fins on the aquarium floor

Corydoras catfishCorydoras

coypu

CoypuMyocastor coypus

crab

crayfish

CrayfishAstacoidea and Parastacoidea (freshwater crayfish)

crocodile

CrocodileCrocodylidae

cuttlefish

CuttlefishSepiida

D

Blue discus with a round body, red eye and fine fin markings

DiscusSymphysodon

dolphin

DolphinDelphinidae and several river-dolphin lineages

Grey dugong with a downturned muzzle in the Red Sea near Marsa Alam, Egypt

DugongDugong dugon

E

Male elephant seal with a large inflated nose raised on a beach near females and pups

Elephant sealMirounga

Dark grey Eurasian coot with a red eye and white forehead standing on a bank

Eurasian cootFulica atra

Small, slender silvery anchovy with a bluish back on a sandy seabed

European anchovyEngraulis encrasicolus

European chub with large scales, an elongated body and a broad head in an aquarium

European chubSqualius cephalus

European eel (Anguilla anguilla) with a long body and fins continuous around the tail

European eelAnguilla anguilla

European flat oyster (Ostrea edulis) with a rough shell on the seabed

European flat oysterOstrea edulis

European perch (Perca fluviatilis) viewed from the side underwater

European perchPerca fluviatilis

European squid (Loligo vulgaris) with an elongated mantle, side fins and tentacles

European squidLoligo vulgaris

Bright green tree frog with a dark side stripe clinging to a twig

European tree frogHyla arborea

F

Silver freshwater angelfish with orange patches and dark markings beside aquatic plants

Freshwater angelfishPterophyllum scalare

frog

G

Giant oceanic manta ray seen from the front and side in blue water with broad fins spread

Giant oceanic manta rayMobula birostris

Grey-brown round goby with a large head and high-set eyes resting on a bed of mussels

Goldfish (Carassius auratus) with orange scales

GoldfishCarassius auratus

Silvery-blue gourami with a dark spot on its side and white-spotted fins

GouramiTrichopodus

great white shark

Great white sharkCarcharodon carcharias

Male guppy with blue-green markings and a patterned yellow tail among aquatic plants

GuppyPoecilia reticulata

H

hammerhead shark

Hammerhead sharkSphyrnidae

Grey harbour porpoise with a short snout and small triangular dorsal fin swimming in greenish water

Harbour porpoisePhocoena phocoena

hippopotamus

HippopotamusHippopotamus amphibius

humpback whale

Humpback whaleMegaptera novaeangliae

J

jellyfish

JellyfishCnidaria: Scyphozoa, Cubozoa and jellyfish-form Hydrozoa

K

Bright orange koi with black spots swimming in grey water

KoiCyprinus rubrofuscus

L

A Hirudo leech with an elongated body and longitudinal markings

M

manatee

ManateeTrichechus spp.

Silvery horse mackerel with large eyes and a lateral line of bony scutes on ice among other fish

Mediterranean horse mackerelTrachurus mediterraneus

Dark-shelled Mediterranean mussels clustered on an underwater rock

Mediterranean musselMytilus galloprovincialis

minke whale

Minke whaleBalaenoptera acutorostrata

Grey, finely spotted mollies swimming among green aquatic plants

MollyPoecilia sphenops

N

narwhal

NarwhalMonodon monoceros

Neon tetra with a bright blue stripe and red lower rear half

Neon tetraParacheirodon innesi

Northern pike (Esox lucius), showing its elongated snout and pale body markings.

Northern pikeEsox lucius

O

Silver-grey ocean sunfish with a tall flattened body and long top and bottom fins

Ocean sunfishMola mola

octopus

OctopusOctopoda

orca

OrcaOrcinus orca

Large dark Oscar fish with orange patches and a red eye on a black background

Oscar fishAstronotus ocellatus

otter

OtterLutrinae; Lutra lutra is the Eurasian otter, Lontra canadensis the North American river otter

P

penguin

PenguinSpheniscidae

piranha

PiranhaSerrasalmidae: piranhas, including Pygocentrus and Serrasalmus

Old illustration of a Pontic shad, an elongated fish with large scales and a forked tail

Pontic shadAlosa immaculata

Prussian carp seen from the side underwater

Prussian carpCarassius gibelio

White-spotted pufferfish with a small mouth swimming beside coral in blue water

PufferfishTetraodontidae

R

Pinkish-silver red mullet with red blotches and two chin barbels on a sandy seabed

Red mulletMullus barbatus

Water turtle with yellow stripes and a red patch behind the eye on a rock

Red-eared sliderTrachemys scripta elegans

S

sawfish

SawfishPristidae

sea lion

Sea lionOtariidae (sea lions; family also includes fur seals)

Sea otter with thick brown fur and a pale head floating on its back in the water

Sea otterEnhydra lutris

seahorse

SeahorseHippocampus

seal

shark

SharkSelachimorpha (sharks within Chondrichthyes)

Yellow platy with red tones, a red head and black-edged fins on a dark background

Southern platyfishXiphophorus maculatus

sperm whale

Sperm whalePhyseter macrocephalus

starfish

StarfishAsteroidea

stingray

StingrayMyliobatiformes; Dasyatidae includes whiptail stingrays

Sterlet (Acipenser ruthenus), a sturgeon with a pointed snout and bony scutes

SturgeonAcipenseridae

swordfish

SwordfishXiphias gladius

T

Olive-green tench with a reddish eye swimming underwater

TenchTinca tinca

tuna

TunaThunnini (within Scombridae)

W

walrus

WalrusOdobenus rosmarus

Wels catfish (Silurus glanis) swimming underwater

Wels catfishSilurus glanis

whale

Side view of a white-spotted whale shark swimming through blue water among smaller fish

Whale sharkRhincodon typus

Z

Zander (Sander lucioperca) with its elongated body and large eyes

ZanderSander lucioperca

Several small, slender zebrafish with blue and silver stripes along the body

ZebrafishDanio rerio