Expert on
portal about pests and methods of dealing with them

Interesting facts about crustaceans

5 minutes. for reading
We found 22 interesting facts about crustaceans

Armored invertebrates

They primarily live in aquatic environments, where they live on the seabed (the record holder was found at a depth of 10,5 km) or swim in the water depths as plankton. Some of them have also colonized land, although some terrestrial crustaceans have to return to water for reproductive purposes.

This is the fourth largest group of invertebrate animals, second only to insects, arachnids and mollusks.


Crustaceans are arthropods that include lobsters, crabs, crayfish, shrimp, krill, millipedes, and barnacles, among others.

At the moment, about 67 species of these animals have been described.

The first crustaceans appeared on Earth in the Middle Cambrian more than 500 million years ago.

Crabs and shrimp appeared only in the Jurassic period (201 - 145 million years ago), and lobsters - in the Cretaceous period (145 - 66 million years ago).

Most crustaceans live in aquatic environments, but there are also terrestrial species.

Terrestrial crustaceans include mainly centipedes, some crabs and hermit crabs.

Like all arthropods, crustaceans have an external shell.

As crustaceans grow, they must molt and move to a safe location where they shed their outer shell and quickly increase in size before the next shell hardens.

A characteristic feature of crustaceans is two pairs of antennae, three pairs of oral legs, and all, except the first pair of antennae, are biramous (divided into exopodites and endopodites).

For comparison, arachnids have no antennae at all, and insects only have one pair.

Their body may consist of two or three parts (tagmas), and in some cases it is simply impossible to separate individual elements.

Some crustaceans have a head, thorax and abdomen, but there are also those in which these elements cannot be distinguished. Moreover, the structure of their body is divided into the head and body.

Most crustaceans breathe using gills, but some species have developed primitive lungs.

Crabs have lungs Khasmagnat grainy and hermits Enoch и Birgus. They consist of tissues similar to gills, but are more adapted to breathing atmospheric air. In addition to lungs, land hermit crabs also have gills, but these are too ineffective to allow them to breathe underwater, so these crabs can easily drown even in shallow water.

The diet of different crustacean species varies greatly.

Most are scavengers, but some are predators, some are herbivores, and others are filter feeders or parasites. The victims of parasitic crustaceans most often are fish, whales or other crustaceans.

Most crustaceans reproduce sexually, but there are also hermaphrodites and species that change sex with age.

In crustaceans, internal fertilization occurs. Most aquatic crustaceans guard their eggs and carry them on their legs, body cavities, or nesting pouches until they hatch, while others simply attach them to rocks or release fertilized eggs into the water.

Once the egg hatches, one of three types of development may occur, depending on the species.

Some crustaceans hatch in a form similar to the adult and grow as they molt (epimorphosis). Others hatch as larvae and, with each molt, form subsequent body segments (anamorphoses), while others, like insects, undergo metamorphosis, which may consist of several larval stages (metamorphoses).

The strangest of all parasitic crustaceans is Simofoa, which attacks fish and lives in their mouths.

This crustacean feeds on the blood of its host. It attaches to the tongue and slowly replaces its function until it disappears completely. At this point, the cymotoa completely replaces the tongue, and the fish begins to use the parasite as its substitute. It is the only known parasite that replaces an organ of its host.

The largest crustacean is the Japanese Pacific crab. The span of its legs can reach 3.7 meters, the length of the cephalothorax is 40 centimeters, and the weight of an adult is about 19 kilograms.

Their body is usually red with white speckles, which allows them to be perfectly camouflaged against the ocean floor. There are also completely red or white individuals. They live exclusively near the Japanese coast around the island of Honshu and around the northeastern coast of Taiwan.

This is the smallest crustacean in the world Stigotantulus rods.

These are parasites that live on copepods. The body length of representatives of this species does not exceed 0.1 mm.

Most hermit crabs live in shells. However, they do not produce them themselves, but occupy the shells of other animals.

Some hermit crabs do not live in shells at all, but live, for example, in rock crevices or burrows. An example of such a species is the palm crab, which is a terrestrial animal and only in its larval stage lives in water and lives in snail shells.

The pistol shrimp is a marine horror for small fish and invertebrates. He hunts his victims in a very unusual way.

The right claw of these animals has been modified, allowing them to attack a target with an air bubble accelerated to speeds of over 100 km/h. Such a bubble can stun a small fish or crack the shell of a hermit crab or mollusk.

Centipedes are also very dangerous marine crustaceans. At the moment, about 450 million of these animals have been described.

Like pistol shrimp, they are capable of striking their victims with a modified second pair of legs. They may have blunt, hardened protrusions or pointed ends. The attack speed of these legs can reach 83 km/ha. During the attack, as with the Pistol Shrimp, an air bubble is created.

Millipedes with blunt legs choose crabs, snails and mussels as victims, the shells of which they easily split. Species with pointed legs select prey with a soft, uncovered body that they can pierce—primarily fish.


The dwarf crustacean is a crustacean that has survived to this day almost unchanged for 220 million years. This is a living fossil from the Middle Triassic.

Considering that dinosaurs appeared on Earth about 245 million years ago, this result is impressive. Coppice lives in the temperate climate of Western and Central Europe. It can be found in Poland; in our country it is a partially protected species.

Cancers are able to regenerate lost legs.

However, they never grow back to their original size.

Crustaceans are readily consumed by people, especially those living in the seas and oceans.

Most of what ends up on our plates are decapods, that is, crabs, lobsters, shrimp and crayfish.

Krill also figures into the fishery, and although it constitutes one of the largest biomasses on the planet (Antarctic krill alone is estimated at 380 million tons), it is caught in quantities not exceeding 120 million tons per year.

Krill is often used not as a dish, but as a raw material for the production of oil - a very useful nutritional supplement with a large amount of omega-3 acids, mainly EPA, DHA with high bioavailability and rich in astaxanthin.

The annual production of edible crustaceans exceeds 10 million, of which more than 8 million come from Asia.

The world's largest supplier of crustaceans is China, with more than half of the animals sold coming from there. These animals are obtained either through fishing or aquaculture.

Coconut crabs have the strongest grip of any animal.

Hence their name - their claws are capable of splitting coconuts. The gripping force of an adult male is about 300 N; in comparison, the gripping force of a coconut crab's claws is over 1700 N.

Interesting FactsInteresting facts about the common house martha
The next
Interesting FactsInteresting facts about reptiles

Without Cockroaches