Swimming Animals

Euphausia superba

Antarctic krill is a small, shrimp-like crustacean that forms the foundation of the entire Antarctic food web, supporting whales, seals, penguins, and countless fish species. Despite its tiny individual size, its total biomass is estimated to be one of the largest of any animal species on Earth, gathering in massive swarms that can stretch for kilometers and be seen from space.

Ambystoma mexicanum

The axolotl is a remarkable salamander from a single lake system in Mexico that never fully undergoes metamorphosis, instead retaining its larval, gilled form and living its entire life underwater. This permanent juvenile state, called neoteny, along with its extraordinary ability to regrow lost limbs, organs, and even parts of its brain, has made it one of the most studied animals in modern regenerative biology research.

Basiliscus basiliscus

The basilisk lizard, nicknamed the 'Jesus Christ lizard,' is famous for its remarkable ability to run upright across the surface of water for short distances without sinking. Native to the rainforests of Central and northern South America, it relies on this unusual skill primarily to escape predators.

Tursiops truncatus

The bottlenose dolphin is one of the most widely-recognized and intelligent marine mammals, found in temperate and tropical oceans worldwide.

Pygoscelis antarcticus

The chinstrap penguin is named for the narrow black band running under its chin, giving it the appearance of wearing a tiny helmet strap. Among the most numerous penguin species in the world, it breeds in enormous colonies across the Antarctic Peninsula and surrounding sub-Antarctic islands.

Mobula birostris

The giant oceanic manta ray is the largest ray species in the world, with a wingspan that can reach up to 7 meters across. Despite its enormous size, it feeds exclusively on some of the ocean's smallest organisms, filtering huge volumes of zooplankton through specialized gill plates as it swims.

Eunectes murinus

The green anaconda is the heaviest snake species in the world, a massive non-venomous constrictor found in the swamps, rivers, and flooded grasslands of South America. Unlike many large snakes, it spends much of its time submerged in water, where its bulk is supported and it can ambush prey coming to drink.

Eretmochelys imbricata

The hawksbill sea turtle is a critically endangered marine reptile named for its narrow, pointed beak, which resembles a bird of prey's hooked bill. It plays a vital ecological role on coral reefs by feeding primarily on sponges, helping maintain the balance of reef ecosystems by preventing sponges from overgrowing and smothering coral.

Dermochelys coriacea

The leatherback is the largest sea turtle species in the world and the only one without a hard bony shell, ranging farther into cold water than any other reptile.

Enhydra lutris

The sea otter is the heaviest member of the weasel family and one of the few mammals known to use tools, cracking open shellfish with rocks while floating on its back.

Pristella maxillaris

The X-ray tetra is a small freshwater fish native to slow-moving rivers and streams in South America, named for its almost completely transparent body that reveals its skeleton and internal organs. Its see-through appearance has made it one of the most recognizable and popular small fish in the freshwater aquarium hobby worldwide.

Thunnus albacares

The yellowfin tuna is a large, fast-swimming fish found in tropical and subtropical waters across the world's oceans, prized both as one of the ocean's most powerful predators and as one of the most commercially important fish species for human consumption. Its name comes from the bright yellow coloring of its dorsal and anal fins, which become especially long and dramatic in mature adults.

Danio rerio

The zebra danio is a small freshwater fish native to streams and rice paddies across South Asia, named for the five uniform, horizontal blue stripes running along its silvery body. Beyond its popularity as an aquarium fish, it has become one of the most important model organisms in modern biological and medical research.