The oceans are the habitat of a great variety of animals, so that all zoological groups are represented in the vast marine ecosystems that occupy the different latitudes of the planet. So far, many species have been identified that live in these places, however, their immensity undoubtedly protects many others that surely remain unknown. It has been reported [1] in a census between 2000 and 2010 that aquatic biodiversity exceeds 250,000 species, however, scientists estimate that the figure it can reach a million or even double this value.
In this article on our site we want you to learn more about the marine animals, so read on to discover the types that exist, their main characteristics and some examples
Characteristics of marine animals
Marine animals have a series of characteristics that allow them to develop properly within this type of habitat. As we have mentioned, there is a great diversity of species that live in the world's oceans and seas, so, depending on the taxonomic group, the species will have one or another adaptation to live in the marine environment. Thus, there are no unique traits in marine species
We can say that real marine animals are those that live exclusively in this type of water bodies or that spend most of their time inside them because they have the necessary adaptations to do so. On the other hand, others such as certain birds only enter the water to hunt, but they do not have the ability to stay submerged for a long time. So, they are rather species associated with coastal marine environments.
Next, let's learn about certain characteristics of marine animals that will make us see in a better way how diverse and different they can be:
- Respiration can be through gills, as in fish, pulmonary, as in mammals, or by diffusion through skin or tissue. In this sense, depending on the type of respiration, some animals can remain permanently underwater, such as fish, and others must come to the surface to breathe air, which is the case of marine mammals, for example.
- Marine animals have the ability to regulate both water and the amount of s alt, for which they use various anatomical and physiological means that maintain water and salinity balance in the body.
- The trophic base of the oceans is made up of plankton, on which many marine species depend for their subsistence. Others consume larger algae or aquatic plants, but there are also carnivorous predators, who feed by hunting other animals.
- Certain marine species, such as some sharks, have the ability to tolerate hypersaline environments, while other types of fish cannot.
- Some marine animals, thanks to body regulation mechanisms, can pass into brackish and even freshwater bodies, others are specific to s alty environments.
- There are animals that live mainly in the seas, but that eventually come to land to perform certain vital functions, for example, the turtles when they spawn or sea lions when they mate.
- Most marine species have external fertilization, however, many others, such as mammals and sharks, have internal fertilization.
- The migratory behavior is common in various marine animals, which is influenced by changes in temperature, currents, availability of food and reproductive or breeding seasons.
- Within the biodiversity of the seas we find an important variety of sessile animals, which, thanks to the constant flow of currents, manage to feed and reproduce. Such is the case of sponges, anemones and corals, among others. On the contrary, there are certain fish, dolphins, seals and several others that are very agile and fast in the water.
Types of marine animals
We have mentioned that the diversity of marine animals is extraordinarily vast, so each group, both invertebrates and vertebrates, is represented in this environment. Let's get to know the types of marine animals that exist:
- Arthropods
- Mollusks
- Annelids
- Flatworms
- Nematodes
- Echinoderms
- Cnidarians
- Porifera
- Fishes
- Mammals
- Birds
- Reptiles
List of marine animals
After knowing general aspects about sea and ocean animals, now let's see specific examples about them. To do this, we will follow the types mentioned above.
Examples of marine arthropods
Within marine arthropods we find the following groups, within which we mention specific examples:
- Pycnogonids: sea spiders.
- Remipedios: blind crustaceans.
- Cephalocarids: horseshoe shrimp.
- Maxillopods: copepods and barnacles, among others.
- Malacostracea: amphipods, krill, crabs, shrimp and lobster, among others.
Examples of marine molluscs
This is quite a diverse group, so we can mention the following examples:
- Solenogastros: they are shaped like worms and we highlight, for example, Neomenia carinata.
- Polyplacophores: chitons such as Acanthochiton garnoti.
- Scaphopods: tusked shell like Antalis vulgaris.
- Gastropods: sea snails.
- Bivalves: clams, oysters, cockles and mussels, among others.
- Cephalopods: octopus and squid.
Examples of marine annelids
Annelids are ring worms and some marine examples are:
- Polychaetes: Clam worm (Nereis succinea) and Pompeii worm (Alvinella pompejana).
- Hirudineos: marine leech (Pontobdella muricata).
Examples of marine flatworms
The flatworms correspond to the flatworms and, within this group, we have:
- Turbellaria: marine planaria of the order polycládidae.
- Cestodes: intestinal parasites of whales, such as the species Tetragonoporus calyptocephalus.
Examples of marine echinoderms
Echinoderms are well-known marine animals, since within this group we find:
- Starfish: a clear example is the common starfish (Asterias rubens), but don't hesitate to meet them all by visiting this other article: "Types of starfish".
- Sea lilies: the Mediterranean comatula (Antedon mediterranea) is a good example.
- Sea urchins: such as the fire urchin (Astropyga radiata).
- Sea cucumbers: like donkey manure (Holothuria mexicana).
Examples of marine cnidarians
Cnidarians are a group with many marine forms, some examples are:
- Scyphozoa: like the crown jellyfish (Atolla wyvillei).
- Cubozoa: box jellyfish, such as the sea wasp (Chironex fleckeri).
- Anthozoa: sea anemones, such as the tree anemone (Actinodendron arboretum).
Examples of marine porifera
They are sessile marine animals, that is, they do not move. Within the group we highlight:
- Calcareous: calcium carbonate sponges such as Sycon raphanus.
- Hexactinélidas: like the flower basket of Venus (Euplectella aspergillum).
- Demosponges: like the giant barrel sponge (Xestospongia testudinaria).
Examples of marine fish
They include a great diversity of species and some examples are:
- Cyclostomes: Jawless fish such as Hagfish (Myxini).
- Chondrichthyans: cartilaginous fish such as great white shark (Carcharodon carcharias).
- Actinopterygian: Ray-finned fish, for example swordfish (Xiphias gladius).
Examples of marine mammals
The group of mammals is also well represented among marine animals:
- Cetacea: such as baleen whales, for example, the Greenland whale (Balaena mysticetus) and toothed whales, as in the case of the coastal common dolphin (Delphinus capensis).
- Carnivores: such as the Mediterranean monk seal (Monachus monachus) or the sea otter (Enhydra lutris), among others.
- Sirenians: An example is the Caribbean manatee (Trichechus manatus).
Examples of seabirds
Although this is not such a large group, we can mention:
Sphenisciformes: the peculiar penguins like the emperor (Aptenodytes forsteri).
Examples of marine reptiles
Finally, we find the marine reptiles:
- Squamous: such as the marine iguana (Amblyrhynchus cristatus) and the beaked sea snake (Enhydrina schistosa)
- Testudines-All sea turtles, such as the green sea turtle (Chelonia mydas).
- Crocodiles: such as the marine or s altwater crocodile (Crocodylus porosus).
Other examples of marine animals
As we have mentioned, the marine world is immense and incredible, which is why there are many species that inhabit it. In addition to the above, we present another very varied list of marine animals and where you will recognize several species for being extremely well-known:
- Meagre
- Bull shark
- Sablefish
- Swallowfish
- Anchovy
- Mere
- Hake
- Sea Eel
- Snapper
- Stripe
- Sardine
- Fiddler Crab
- Barnacle
- Prawn
- Hermit crab
- Acorn
- Leatherback
- Hawksbill turtle
- Loggerhead Turtle
- Black turtle
- Killer Turtle
- White Turtle
- Kemp's ridley sea turtle
- Ringed Sea Serpent
- Yellow Sea Serpent
- Black Sea Urchin
- Captain's Star
- Sand Star
- Prickly Star
- Black Sea Cucumber
- Brown Sea Cucumber
- Ophioderma
- Purple Heart Hedgehog
- Purple Hedgehog
- Portuguese man-of-war
- Brain Coral
- Killer whale
- Southern dolphin
- Chilean Dolphin
- Australian Snub-nose Dolphin
