Necton: What is and examples

We call necton al set of organismsusually of important size, that actively swim in aquatic systems both in the oceans and the seas and in fresh water bodies. These organisms have certain mechanisms that allow them to actively mobilize with intentional movements and thus overcome strong currents. The species that constitute the necton are pelagic speciesthat is, that inhabit the water column and that are independent of the background. It should be noted that certain species can remain close to the bottom at some point in the day, but the rest of it move continuously. Although they are constantly swimming, many of them are looking for sites to take refuge, such as trunks, algae or objects that float.

Animals that are part of the Necton have great tolerance against various conditions, such as temperature, pressure and salinity changes, and it is for this reason that they present such wide distributions.

The necton is formed by different groups of animals Being the main ones: crustaceans, molluscs, bone and cartilaginous fish, reptiles and mammals. All of them They present particular adaptations to be able to swim, feed and defend against their predators. When they move most of the time, they have a great development in their muscles and, in turn, present adaptations in their circulatory, respiratory and nervous systems, with their organs of the well -developed senses. Let’s know some examples:

Swimmers

Despite not having organs specialized in flotation, swimming crabs remain on surface due to their low density. Some species of these crustacean individuals have the rowing legs that favor swimming. Know more about crustaceans: what are, types, characteristics and examples.

Cephalopods

Characterized by presenting a series of tentacles that surround their head, they constitute the main group of mollusks that we can find in the Necton. Although in most of them the shell is reduced, there are very rare species that have an external shell and are considered living fossils. Here you can read more about cephalopods: what are, examples and characteristics.

Cephalopods without external shell:

• Squids: The squid swim rapidly thanks to membranous replicues that have the sides of their body and actively beat. Did you know that they are able to move through jet propulsion? Since, by expelling water through a tube they have, the animal can be driven through a retropropulsion current touring large distances.
• Octopos: The octopus use their eight tentacles to swim, but they are slower than squid since body is less hydrodynamic. Many times they travel great distances thanks to a mechanism similar to that of squid.

Cephalopods with external shell:

• Nautilus: Inhabitant of the waters of the Pacific Ocean, nothing quickly, although with less speed than squid.
• Argonaut: To be able to scroll use arms with membranes, similar to umbrellas.

Bone and cartilaginous fish

Necton’s fish can be classified into two large groups: gregarious, who live forming schools of a large number of individuals; and the lonely ones, who are usually higher and usually feed on gregarious species. Within the pelagic fish that form schools we find bone fish such as:

• Tuna
• Anchovy
• Sardine
• Salmon

Within the cartilaginous fish that are usually more lonely we find sharks: carnivores and predators that generally inhabit the pelagic coasts and can immerse themselves in great depths. Examples:

• Hammer shark
• Tigre Shark
• White Shark
• Mako Shark

Here you can learn more about the classification of fish.

Sea turtles

With their modified limbs for swimming in the form of pallets, they are migratory reptiles capable of crossing great distances in the oceans. There are seven species worldwide which are distributed widely:

• Green turtle
• Lute turtle
• Carey turtle
• Cabezona turtle
• Olivaceous turtle
• Flat turtle
• Lora turtle

Know here more about the types of sea turtles and their characteristics.

Sirenians

The Sirenians live in tropical areas, but reach estuaries and rivers. Its previous members are modified in fins suitable for swimming; Its posterior members are absent (they have been reduced) and their tail has a palette shape. Within this group we find:

• Manatee
• Dugongo

In this other article you can learn much more about Sirenian mammals: characteristics and examples.

Pinnípedos

They spend much of their life in the necton, but they reproduce on the mainland. Your body is hydrodynamic and your previous limbs are transformed into fins which facilitate swimming. Examples of them are:

• MORSAS
• Focas
• Marine lions
• Marine elephants
• Marine wolves

Here you can learn about the difference between seal, León Marino and Morsa.

Cetaceans

Adapted to necttonic life, they present the body in a fusiform way which makes them more hydrodynamic. Its previous members have transformed into fins and have a thick layer of fat that works as thermal insulator. Inside the cetaceans we find:

• BALLENASC
• Orcas
• Dolphins
• Tercoote

The necton presents great importance because:

• The necttonic communities They constitute complex trophic networks And they function as energy and nutrient regulators, for their ability to displace within and between ecosystems.
• House a Large percentage of biodiversitysince necttonic communities reproduce, feed and migrate through aquatic systems, thus completing their life cycle.
• The necton is important as object of study To investigate and generate information about population dynamics, behaviors, interactions Among different species, life cycles, for the realization of management plans and the determination of conservation sites.
• Provides goods and services to human beingsespecially for food. Anthropogenic pressures, especially overfishing by large companies, generate irreparable consequences in the environment and in societies that use fishing as a subsistence means.

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