Black sea marble crab. Marble crab in a crevice between stones

Subtype: Crustaceans Class: Higher crayfish Squad: Decapod crustaceans Suborder: Pleocyemata Infrasquad: Crabs Superfamily: Grapsoidea Family: Grapsidae Genus: Pachygrapsus View: marble crab Latin name Pachygrapsus marmoratus (Fabricius, 1793) Synonyms

Description

Area

The range of the marble crab covers the Black and Mediterranean Seas, the Atlantic Ocean from the North-West coast of France to the Azores. The marble crab is found on the coast of the Caucasus and the Crimean Peninsula at shallow depths with a rocky or rocky bottom. The marble crab is able to go ashore and do without water for some time. The number of marbled crab is small; it is listed in the Red Book of Ukraine. Protected in Ukrainian nature reserves Cape Martyan and Karadag. A significant number of these crabs are caught uncontrollably to make handicraft souvenirs for sale to tourists.

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Marble crab underwater

Security Notes

It is listed as an endangered species in the Red Book of Ukraine. The number in the Black Sea is declining due to habitat pollution and uncontrolled fishing.

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Notes

Excerpt characterizing the Marble Crab

The officer praised the knife.
- Please take it for yourself. I have a lot of these...” Petya said, blushing. - Fathers! “I completely forgot,” he suddenly cried out. “I have wonderful raisins, you know, the kind without seeds.” We have a new sutler - and such wonderful things. I bought ten pounds. I'm used to something sweet. Do you want?.. - And Petya ran into the hallway to his Cossack and brought bags containing five pounds of raisins. - Eat, gentlemen, eat.
– Don’t you need a coffee pot? – he turned to Esaul. “I bought it from our sutler, it’s wonderful!” He has wonderful things. And he is very honest. This is the main thing. I will definitely send it to you. Or maybe flints have come out and become abundant - because this happens. I took with me, I have here... - he pointed to the bags, - a hundred flints. I bought it very cheap. Please take as much as you need, or that’s all... - And suddenly, afraid that he had lied, Petya stopped and blushed.
He began to remember if he had done anything else stupid. And, going through the memories of this day, the memory of the French drummer appeared to him. “That’s great for us, but what about him? Where did they take him? Was he fed? Did you offend me?" - he thought. But having noticed that he had lied about the flints, he was now afraid.
“You could ask,” he thought, “and they’ll say: the boy himself felt sorry for the boy. I'll show them tomorrow what a boy I am! Would you be embarrassed if I asked? - thought Petya. “Well, it doesn’t matter!” - and immediately, blushing and looking fearfully at the officers, to see if there would be mockery in their faces, he said:
– Can I call this boy who was captured? give him something to eat... maybe...
“Yes, pathetic boy,” Denisov said, apparently not finding anything shameful in this reminder. - Call him here. His name is Vincent Bosse. Call.
“I’ll call,” said Petya.
- Call, call. “Pitiful boy,” Denisov repeated.
Petya was standing at the door when Denisov said this. Petya crawled between the officers and came close to Denisov.
“Let me kiss you, my dear,” he said. - Oh, how great! how good! - And, having kissed Denisov, he ran into the yard.
- Bosse! Vincent! – Petya shouted, stopping at the door.
- Who do you want, sir? - said a voice from the darkness. Petya answered that the boy was French, who was taken today.
- A! Spring? - said the Cossack.
His name Vincent has already been changed: the Cossacks - into Vesenny, and the men and soldiers - into Visenya. In both adaptations, this reminder of spring coincided with the idea of ​​a young boy.
“He was warming himself by the fire there.” Hey Visenya! Visenya! Spring! – voices and laughter were heard in the darkness.
“And the boy is smart,” said the hussar standing next to Petya. “We fed him just now.” Passion was hungry!
Footsteps were heard in the darkness and, bare feet splashing in the mud, the drummer approached the door.
“Ah, c"est vous!" said Petya. “Voulez vous manger? N"ayez pas peur, on ne vous fera pas de mal,” he added, timidly and affectionately touching his hand. - Entrez, entrez. [Oh, it's you! Are you hungry? Don't be afraid, they won't do anything to you. Enter, enter.]
“Merci, monsieur, [Thank you, sir.],” answered the drummer in a trembling, almost childish voice and began to wipe his dirty feet on the threshold. Petya wanted to say a lot to the drummer, but he didn’t dare. He stood next to him in the hallway, shifting. Then in the darkness I took his hand and shook it.

On the Black Sea coast, wherever there are large stones, you can find crabs. Moreover, you can’t even imagine how much the shore and shallow waters are teeming with these crustaceans. During the day you can see several small crabs swarming on the rocky algae at the very edge of the water. But as soon as they notice any movement within a radius of several meters, they disappear in all directions. And, of course, the time of reign for crabs is twilight, here they appear in thousands. Where do the crabs hide the rest of the time? The best shelters for them are cracks and crevices between stones, where they squeeze through, and backwards. So that curious eyes on stalks and powerful claws look out - try to pick it out from there. The pictures below show mostly marble crab (Pachygrapsus marmoratus). In Omega Bay in Sevastopol, swimming with a mask between the rocks, I easily found their shelters under water. It is enough to look into any crack between the stones to see in its depths glittering eyes on stalks and threatening claws. True, it was dark and cloudy there, so I had to use a flash.

marble crab(lat. Pachygrapsus marmoratus) - a type of crab, got its name because of the characteristic pattern - dark wavy lines on the shell. Other names: spider crab, sea spider. In behavior it really resembles many spiders. The local name on the southeastern coast of Crimea is Gypsy.

The marble crab has a blue-green to dark brown shell, mottled with many light stripes, reminiscent of variegated marble. Because of its dark color and long legs, it is often called the spider crab.

This is the only Black Sea crab that runs out of the water and travels along coastal stones and rocks. At night, they can climb 2-5 m up rocks, and on gentle slopes move 5-10 m away from the water’s edge. However, at the first danger, they instantly take off and throw themselves into the water or the nearest crevice.

The shape of the sea spider's shell is trapezoidal. The marble crab is small in size. Basically, the cephalothorax of an adult reaches a width of 45-50 mm. The maximum size is 6 centimeters. The upper surface of the flat carapace is sometimes overgrown with balanuses (small crustaceans) and algae. The marble crab, like other representatives of the genus decapod crustaceans, has ten strong and long legs. The two front legs are turned into claws. The walking legs of the Spider Crab are abundantly covered with hairs.

Life expectancy: 3 years. Habitat: coastal zone: at the very edge of the water and even outside the water (up to 5 m). The marbled crab lives on rocks, in the cracks of breakwaters, piers or similar places.

The marble crab climbs onto stones and rocks protruding from the water and cleans their surfaces. At the slightest danger, it quickly crawls into the nearest crevice, and in its absence, it rushes into the sea. The crab easily tolerates drying out and loves to bask on sunlit rocks.

Builds a home. Having chosen a stone, it begins to squeeze under it - pulling out sand and small stones with its claws and pushing out sand and small stones with its paws, the marble crab hides in the resulting niche. Having fed well and accumulated nutritional reserves, it hides in a safe shelter. At night, he carefully climbs out of his old shell. Lost legs and the claws are restored after two or three molts. The marble crab is perfectly camouflaged among mussels and algae. Doesn't know how to bury itself in sand.

The habitat of the marbled crab covers the Black, Azov and Mediterranean Sea, Atlantic Ocean from the North-West coast of France to the Azores. The marble crab is found on the coast of the Caucasus and the Crimean Peninsula at shallow depths with a rocky or rocky bottom.

And in the last two photos there is a different type of crab - Stone crab(lat. Eriphia verrucosa). The stone crab is the largest crab in the Black Sea. The width of its shell is 9-10 cm. It prefers to live deeper, although it is often found close to the shore, but this is only in deserted rocky places.

If all bottom crustaceans are primarily scavengers (by the nature of their diet), then the stone crab, strong and aggressive, can be a fast and dexterous predator. In ambush he lies in wait for snails, worms and small fish. Its claws have monstrous strength - they snap like seeds, shells of mollusks and hermit crabs. Their muscle fibers at the molecular level differ from those of animals and humans (not in our favor).

The color of the stone crab's shell is always the same as that of the stones among which it lives. Basically, it is a red-brown color, but stone crabs living among yellow sandstones are themselves quite light.

Names: marble crab, spider crab, sea spider.

Area: Black and Mediterranean seas, Atlantic Ocean (coast of France and Morocco).

Description: marble crab is small, agile, with a flat, square shell (size 3.5x4.5 cm). The edge of the front side between the eyes is particularly straight and wide with three sharp teeth on each side. Breathes through gills. External skeleton. Left claw, with small, tightly closed teeth. The right claw, larger, with curved teeth and a gap in the middle, looks like forceps. The crab's legs are long and covered with hairs.

Color: the shell is greenish-brown to violet-brown, covered with a wavy pattern similar to marble.

Size: length - 38 mm, width - 43 mm.

Lifespan: 3 years.

Habitat: coastal zone: at the very edge of the water and even outside the water (up to 5 m). The marbled crab lives on rocks, in the cracks of breakwaters, piers or similar places.

Food/food: remains of animals and plants, mollusks, polychaetes, plankton.

Behavior: The marble crab climbs onto stones and rocks protruding from the water and cleans their surfaces. At the slightest danger, it quickly crawls into the nearest crevice, and in its absence, it rushes into the sea. The crab easily tolerates drying out and loves to bask on sunlit rocks. Builds a home. Having chosen a stone, it begins to squeeze under it - pulling out sand and small stones with its claws and pushing out sand and small stones with its paws, the marble crab hides in the resulting niche. Having fed well and accumulated nutritional reserves, it hides in a safe shelter. At night, he carefully climbs out of his old shell. Lost legs and claws are restored after two or three molts. The marble crab is perfectly camouflaged among mussels and algae. Doesn't know how to bury itself in sand.

Reproduction: one female can lay up to 87 thousand eggs.

Breeding season/period: July-August (at a water temperature of 17"C).

Puberty: females mature at 2 years.

Pregnancy/incubation: 25 days.

Offspring: Crab larvae feed on plankton. Metamorphosis with 4 stages.

Population/Conservation Status: The marbled crab is included in the Red Book of Ukraine.

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Sea spiders, also known as spider crabs, also known as marble crabs, live in the Mediterranean, Black Sea and Atlantic Ocean, near the coast of Morocco and France. They are found on the Crimean peninsula and the Caucasus coast, at shallow depths with a rocky or rocky bottom.

Sea spiders are members of the Grapsidae family. These crabs are called "spider" crabs because of their long, dark legs, and they get the name "marble" because of the characteristic pattern on their shell.

Description of the sea spider

The spider crab is small and agile, its body length reaches only 38 millimeters and its width is 43 millimeters. The carapace is square and flat. The anterior edge, located between the eyes, is especially wide and straight, with 3 sharp teeth on each side. The upper part of the shell can become overgrown with small crustaceans called balanuses, as well as algae.

The skeleton is external, respiration is carried out using gills. The left claw has small teeth that tightly close together. The right claw is larger than the left, the teeth are curved, and there is a gap between them. Externally, the right claw resembles forceps. The marble crab is a decapod crustacean, has 10 long, strong legs, covered with hairs. The color of the shell ranges from brownish-greenish to brownish-violet. The shell is decorated with a wavy pattern reminiscent of marble.

Spider crab lifestyle

Sea spiders live in coastal zone, they stay at the very edge of the water and can even leave the water at a distance of up to 5 meters. This is the only Black Sea crab that can run out of the water. In the sea they can live at depths of up to 10 meters.

Marble crabs tolerate drying out well and love to bask on rocks in the sun. Spider crabs build their own homes. The crab selects a stone and begins to climb under it, throwing grains of sand out from under the stone with its claws; the crab hides in the resulting niche. Having accumulated reserves and having eaten well, the sea spider hides in a safe shelter.

Sea spiders feed on the remains of plants and animals, plankton, mollusks and polychaetes. They climb onto rocks protruding from the water and clean their surface. In case of any danger, the crab instantly hides in any crevice, and if there is none, it rushes into the water.

At night, he carefully crawls out of his old shell. At night they can climb onto rocks to a height of 3-5 m. They cannot burrow into the sand, but they are perfectly camouflaged among algae and mussels. If a crab loses a leg or claw, the lost organ is restored after 2-3 molts. The lifespan of a spider crab is 3 years.

Reproduction of marble crabs

Breeding season sea ​​spiders occurs in July-August at a water temperature of about 17 degrees.

One female lays up to 87 thousand eggs. Incubation lasts 25 days. Crab larvae eat plankton. Metamorphosis takes place in 4 stages. Puberty in females occurs at 2 years.

Marble crab population

Like other Black Sea crabs, sea spiders are used to make souvenirs, but they are not commercial species.

Spider crabs are included in the Red Book of Ukraine, because lately their numbers decreased sharply. These crabs are protected in the Karadagsky and Cape Martyan natural reserves.

Closest relatives of spider crabs

There are more than 10 thousand species of decapod crabs with five pairs of legs and bulging, stalked eyes. For example:
Stone crabs are the largest crabs in the Black Sea. The width of the stone crab's shell is about 10 centimeters. They prefer to live deeper, but can be found close to the shore;
The hairy crab looks like a stone crab, but is smaller in size, and its carapace is covered with numerous yellowish hairy bristles. They live closer to the shore, under the rocks;
Mediterranean or grass crabs have a green shell, which is why they are called “grass crabs.” Grass crabs are shallow water dwellers;
Water crab or lilac crab. It is slower and prefers to live exclusively in shallow water;

The swimming crab loves to burrow into the ground. Its small hind legs look like blades; with their help, the crab throws sand on itself. The crab also uses these legs for swimming; the swimming crab is the only one among the Black Sea crabs that can swim;
Blue crab came to the Black Sea from the Mediterranean in the 60s. He arrived in our latitudes with the ballast waters of ships. But the Black Sea water is too cold for young blue crabs, so they are extremely rare;
The invisible crab got its name because it is almost impossible to notice it in algae. These long-legged and skinny sea ​​creatures they know how to camouflage themselves perfectly;
The Pea Crab usually lives among the mussels and can sometimes even crawl inside the shell. It is extremely difficult to see this crab, since an adult is no larger than a ten-kopeck coin;
Freshwater crab is an unusual Crimean crab. It differs not in size, but in origin and lifestyle. From the name it is clear that it lives in fresh water: V mountain rivers and ponds.

Freshwater crabs cannot be spread by currents, so they must travel on land at night. They once crossed the entire continent on foot in this way; it is believed that they originated in Southeast Asia.

Keeping marble crabs in an aquarium

Sea spiders do not dig holes, they prefer to hide under stones, so the bottom of the terrarium is covered with pebbles or sand, and there should be a variety of shelters at the bottom, for example, driftwood, stones, and ceramics. To make the aquaterrarium look more beautiful, it can be enlivened with the help of plants.

About 500 species of crustaceans, including crabs, live on the coast and in the waters of the Black Sea. According to zoologists, there are a total of 18-19 species, having both unique features, so general characteristics. Black Sea crabs mostly small in size (9-10 centimeters across the width of the shell), and only certain species have gastronomic value. Arthropods play an important role in the local ecosystem, and most of them are listed in the Red Book.

General characteristics of crabs

Crabs are called short-tailed crayfish because of their appearance and a small tail, more noticeable in females. Their Latin name Brachyura translates to "short" and "tail", and the animal's evolution dates back 200 million years. A strong shell (exoskeleton) consists of chitin and protects internal organs. Including gills, thanks to which they can live both in water and on land. The head, hidden in a recess in the external skeleton, is small in size, and the eyes are capable of seeing 360 degrees. Crabs use antennae as organs of touch, and with their help they are able to find food, even after losing their sight.

The arthropod moves sideways, using eight of its ten legs, which it can “shed” if necessary and grow back. The two forelimbs of crabs are claw-shaped and are used to defend against enemies, attack prey, tear food and deliver it to the mouth. It can be either plant (various algae) or animal (small mollusks, fish, invertebrates, and sometimes crustaceans). Enemies include certain species predatory fish and shellfish. They are considered “orderlies of the sea”, since the majority are not only predators, but also scavengers.

Most crabs have dimensions measured in centimeters, but some species can grow up to 4 meters in limb span. For a person they represent nutritional value due to meat containing vitamins and microelements.

Crabs of the Russian Black Sea coast

Of the almost two dozen species of Black Sea crabs, only a few are widespread throughout the entire sea coast. The habitat of others is limited areas, since these arthropods are sensitive to biological, climatic and environmental conditions. Five species are widely represented in Russian (and neighboring) waters (all are representatives of the Red Data Books).

Stone crab

Also known as the red rock crab, it gets its name from the color of its shell. Red-brown, it can vary in brown and olive shades, depending on the characteristics of the seabed. The claws are dark and brown, sometimes black. Usually found at depths of 5-30 meters, preferring rocky areas. It has a “personal” shelter and territory, which it protects from other arthropods. Females are prolific in reproduction, laying up to 150 thousand eggs at a time.

Stone crab

The wide shell of the stone crab is covered with small bumps and growths for additional camouflage, and for protection - with a set of spines and prickly microhairs. This is the largest Black Sea species (10 by 8 centimeters in width and length) and the strongest (large claws lift up to 30 times their body weight). Omnivorous, but loves organic matter - carrion, mollusks and invertebrates. The arthropod is quite fleshy, so it serves as an object of fishing, and the shells are used to make souvenirs.

marble crab

The second name is the spider crab (and for residents of the Crimean peninsula, “gypsies”), also named because of its appearance - the pattern of the trapezoid-shaped shell resembles marble, and the long limbs, covered with hairs, look like the legs of spiders. The color of chitin varies between blue, green and brown shades, and is decorated with light stripes. Prefers rocky areas of the bottom and a depth of no more than 10 meters, likes to get out, especially at night, onto land (the only one Black Sea species), rising to heights of up to 2-3 meters.

Black Sea marble crab, female

Having a small size, from 3 to 5 centimeters, it is cautious and timid, and in case of danger it strives to hide in the sea. The marbled crab eats small invertebrates and organic matter. This species of arthropod lives for about 3 years and breeds in shallow water. At the same time, females lay less than 90 thousand eggs. It has no special gastronomic value, but the shell is popular among souvenir manufacturers, which is why it often becomes a target for poachers.

Herbal crab

The second name is Mediterranean. He got his name because of his love for algae, where he often hides from danger or for hunting. This is helped by the greenish shades of the shell, with three characteristic spines, and symbiosis with a number of algae, invertebrates and arthropods that live on the external skeleton, further camouflaging the host. It eats carrion and small inhabitants of the seabed.

Grass crab, male

The shape of the shell resembles a triangle, and an adult grass crab grows up to 7-8 centimeters. By nature, he is a “coward” and a “sprinter” - he himself does not trust his small claws, and runs away from danger at a speed of up to 1 meter per second. You can meet it at a depth of 40 meters. Active at night, during the day it hides in algae or sand. Sensitive to the salinity of water, preferring more “salty” water. Previously, the species was classified as a commercial species.

Swimming crab

As the name suggests, it is the only Black Sea representative that can swim. For this purpose, the hind pair of limbs, wide and flattened, is used. It also helps, if necessary, to quickly bury itself in the sand. Fishermen sometimes call the species “barbers” because it easily cuts nets once caught in them. The dimensions of the shell of light gray-sand shades do not exceed 3-4 centimeters.

Swimming crab

The swimming crab lives at shallow depths and is active mainly at night. It is omnivorous in its diet, and its ability to swim makes it a special opponent. The arthropod is not interesting to fishermen and is rarely used for souvenir crafts.

Blue crab

An alternative name is blue swimming crab. Brought by ships to Black Sea from the waters of the American continent in the mid-19th century. It is quite rare, and the population of the species is not growing, although females lay clutches of 2 million eggs each, due to their “love” for warmth and increased salinity of water.

Blue crab

The edges of the shell are framed with sharp spines, the limbs are painted with bluish tints. The claws, the tips of which are reddish in “girls”, different sizes– the larger one is used to break hard shells, attack and defend, the smaller one helps to cut prey and send food into the mouth.

For life, blue crabs choose muddy and sandy areas of shallow water and river mouths, but they are also found at depths of 30 meters. Adults reach a size of 30 centimeters and can weigh 500-900 grams. Having an aggressive nature, the species is a formidable opponent for natural enemies and representatives of “food”. Its small number does not allow it to be called the largest crab of the Black Sea, and biologists consider it a “guest”. The quantity and properties of the meat have made the arthropod a delicacy and a target for fishing.