Content
- Crab Characteristics
- How many types of crabs are there in the world?
- 1. Crab-violinist
- 2. Christmas Island Red Crab
- 3. Japanese giant crab
- 4. Green Crab
- 5. Blue Crab
- 6. Crab-marie flour
- 7. Yellow Crab (Gecarcinus lagostoma)
- 8. Giant Blue Crab
- More examples of crabs
the crabs are arthropod animals highly evolved. They are able to stay out of the water, which they need to breathe, for a long time. This is possible because they can accumulate water inside, as if it were a closed circuit, changing it from time to time.
In this article by PeritoAnimal we will talk about types of crabs and its main features. We'll also show you a complete list of names and photographs so you can learn to recognize this very interesting animal. Good reading!
Crab Characteristics
You crabs are crustacean arthropods that belong to the Brachyura infraorder. Their body structure is highly specialized, and while arthropods' bodies are normally divided into the head, thorax and abdomen, crabs have these. three fused body parts. Mainly the abdomen, which is very small and located below the carapace.
The carapace of crabs is very wide, often being longer wider than long, which gives them a very flat appearance. They have five pairs of legs or appendages. The first pair of appendages, known as the chelicera, show overgrowth in males of many species.
They can crawl forward slowly, but they usually move sideways, especially when they crawl quickly. most crabs can't swim, although in some species the last pair of legs ends up in a kind of paddle or paddle, broad and flat, which allows them some locomotion by swimming.
the crabs breathe through gills. Water enters the base of the first pair of legs, circulates through the gill chamber, and exits through an area near the eye. The circulatory system of crabs is open. This means that sometimes blood travels through the veins and arteries, and at other times it is poured into the body. They have a heart that can have variable shapes, with ostioles, which are holes through which blood enters the heart from the body, and then travels through the blood vessels.
Crabs are omnivorous animals. they can feed on algae, fish, molluscs, carrion, bacteria and many other organisms. They are also oviparous animals, which reproduce through eggs. The larvae hatch from these eggs and undergo several stages of metamorphosis until reaching the adult stage.
How many types of crabs are there in the world?
There are around 4,500 types or species of crabs. These animals usually live in intertidal areas, such as shores of beaches, estuaries and mangroves. Others live in somewhat deeper waters, and some species even inhabit such inhospitable places as oceanic hydrothermal vents, which reach temperatures of up to 400°C.
Some of the best known types of crabs or those that deserve to be highlighted in nature are:
1. Crab-violinist
O fiddler crab (uca pugnax) inhabits many salt marshes along the shores of the Atlantic Ocean. They are burrow builders, they use to protect themselves from predators, reproduce and hibernate during the winter. They are small crabs, with the largest individuals measuring about 3 centimeters in width.
They show sexual dimorphism, the males being a darker green color with a bluish area in the center of the shell. Females don't have this spot. Males, moreover, may have a overgrowth in one of the chelicerae and, in some cases, both. During courtship, males move their chelicerae in such a way that they appear to be playing the violin.
2. Christmas Island Red Crab
O red crab (natal gecarcoidea) is endemic to Christmas Island, Australia. It lives in a solitary way inside the forest, spending the months of drought buried in the ground, hibernating. When the rainy season starts, during the fall, these animals make a spectacular migrationinpasta to the sea, where they copulate.
the young red crabs are born in the ocean, where they spend a month carrying out various metamorphoses to live in the terrestrial environment.
3. Japanese giant crab
O japanese giant crab (Kaempferi macrochick) lives deep in the Pacific Ocean, near the coast of Japan. They are colonial animals, so they live in very large groups. It is the largest living arthropod in existence. your legs can measure more than two meters long, and they can reach 20 pounds of weight.
Something very curious about these animals is that they adhere to their bodies the debris they find around them to camouflage themselves. If they change their environment, so do the remains. For this reason, they are also known as "decorative crabs". It is one of the crab species that most arouses people's curiosity for its size.
4. Green Crab
O green crab (Maenas Carcinus) is native to the west coast of Europe and Iceland, although it inhabits other parts of the planet as an invasive species, for example, South Africa or Central America. They can have multiple tones, but they are mostly greenish. They do not reach sexual maturity until 2 years of age, when they acquire the size of 5 centimeters. However, its longevity is 5 years in males and 3 in females.
5. Blue Crab
O blue crab (sapidus callinectes) is named for the blue color of its legs, but its carapace is greenish. The claws of its chelicerae are red. They are invasive animals in many areas of the world, although they originate in the Atlantic Ocean. They can live in waters with very different conditions, waters sweet or savory, and even contaminated.
6. Crab-marie flour
The mare crab flour or sand crab (Ocypod quadrata). It is also known as ghost crab and tidal wave. Quite common on beaches, it builds its touch the sand to get away from sea water. It is a very sensitive animal to the cold, but resistant to heat and extremely agile, being able to use its front tweezers to dig, defend itself or get food.
7. Yellow Crab (Gecarcinus lagostoma)
The yellow crab (gecarcinus lobster) lives in tidal regions and is widely seen in places such as Atol das Rocas and Fernando de Noronha. It's an animal endangered, according to the Red Book of Brazilian Fauna Threatened with Extinction by the Chico Mendes Institute for Biodiversity Conservation.
Also known as a thief crab, it has a yellow carapace and usually orange paws. It is between 70 and 110 millimeters. With nocturnal habits, it has marine larval development and its color varies from yellow to purple.
8. Giant Blue Crab
The giant blue crab (birgus latro) is also known as coconut thief or coconut crab. And that makes perfect sense: his favorite food is coconut. It can measure up to 1 meter long, this crustacean has the skillful ability to climb trees. That's right. Don't be surprised if you're in Australia or Madagascar, where he lives, and find a crab looking for coconut in the heights.
In addition to this and other fruits, it feeds on smaller crabs and even on remains of dead animals. Another characteristic of it is the harder abdomen than in other species. Despite being called blue, its color can vary between orange, black, purple and red in addition to the blue itself.
More examples of crabs
Below, we present you a list with other types of crabs:
- Giant Crab (Santolla Lithodes)
- Florida Stone Crab (menippe mercenary)
- Black Crab (ruricula gecarcinus)
- Bermuda Crab (Gecarcinus lateralis)
- Dwarf Crab (Trichodactylus borellianus)
- Swamp Crab (Pachygrapsus transversus)
- Hairy Crab (Peltarion spinosulum)
- Rock Crab (pachygrapsus marmoratus)
- Catanhão (granulate neohelix)
- Mouthless Crab (Crassum Cardisoma)
Now that you already know a series of crab species, including two of them known to be much larger than usual, you might be interested in this video about the world's biggest animals ever found:
If you want to read more articles similar to Types of Crabs - Names and Photographs, we recommend that you enter our Curiosities section of the animal world.