Before entering fully to define the term aquatic animal, we will proceed to
determine its etymological origin. In doing so we discover that the two words
that shape it emanate from the Latin:
• Animal, comes from “animal” that can be translated as any being that has
• Aquatic, meanwhile, derives from “aquaticus”. A term this that is made up of
two clearly differentiated parts: the noun "aqua", which is synonymous with
"water", and the suffix "-tico", which is used to indicate "relative to".
The animals are those living beings that are part of the
kingdom Animalia, can mobilize on their own, they reproduce
sexually way, absorb oxygen to breathe and ingest food. The concept, in its
broadest sense, includes Homo sapiens although, in general, the
use of the term is limited to non-rational animals.
aquatic, meanwhile, is an adjective that refers to what is
linked to water. The word is often used with reference to
those beings that live in it or to objects that, by their nature, remain in the
The aquatic animals, therefore, are those living beings
belonging to the kingdom Animalia who spend most of
their livelihood in the water. This does not mean, however, that they
are only animals capable of breathing underwater, but that there are aquatic
animals that must appear on the surface to capture oxygen.
Although there are many different types of aquatic animals, it is important
to know that they all have a series of common characteristics such as the ones
• They have had to adapt to the sea, specifically its tides and the different
water currents that are produced. Hence some have fins, others have basal discs,
some have shells...
• No less important is that the diet of these living beings, in one way or
another, depends on phytoplankton, which is a species of plant that lives in the
sea and that it is microscopic. And it is located in the nutritional base of
• It should also be noted that they have also had to adapt to the water
temperatures, so each class has mechanisms that do so: scales, pale blood...
The fish are the most representative example of aquatic
animals. These vertebrates have gills to
breathe underwater, so they do not need to get out of the water: in fact, when
they are removed from their environment, they die. The fish have fins for
swimming and usually have a covered body with scales.
Other aquatic animals, however, must rise to the surface to breathe. This is
the case of the dolphin, a mammal that has a
single blowhole to absorb oxygen from the air.
It is important to note that there are aquatic animals that also spend a good
amount of time on land, which is why they are usually
classified as semi-aquatic. The Beavers and hippopotamus,
for example, are in this group.
It should be borne in mind that within the group of aquatic animals there are
several that are in danger of extinction, such as the Mediterranean monk seal,
sea otter, gray whale or napoleon fish, among others.