Unique inhabitants of the sea depths, crabs live with ease in both fresh and saltwater.
The diet of the short-tailed crayfish is varied, depending on the habitat and size of the individual. There are about 93 families of this amazing animal. Some specimens are quite miniature, no more than a few centimeters in the scale of claws. Meet in the population and the real titans – crabs, giants with a span of limbs up to 3.5 meters.
What do crabs eat?
Tropical land crab species move with lightning speed. Feed on everything they can grab as a result of movement. The main diet includes worms, mollusks, even sea urchins. Various crustaceans are in circulation. The animal deals with prey with its powerful claws, and even shells of mollusks and shellfish succumb to the percussive power of extremities. Traveling on land, the crab can catch and eat even a gaping bird.
In the waters of the Mediterranean Sea, the Black Sea, and the Atlantic coast the stone crabs live. Its diet includes bottom dwellers: shrimps, mollusks, crustaceans, various invertebrates. If you find the remains of large animals along the way, the bird crab does not pass by, happily eating the food that fell on his head.
On the European coast, the buoy crab and the land crab live in harmonious tandem. Due to the peculiarities of their body structure, crab crabs are able to move quickly in the water, grabbing prey that swims toward them. Terrestrial species move along the bottom, finding sources of food just below. Due to their different habitat levels, the two species co-exist happily.
Another crustacean species, the Kamchatka crab, lives off the Kamchatka coast. These rather large animals keep in flocks. In warm seasons, they find food in the shallows; when the weather gets cold, they go deeper into the water.
Crabs living in home aquariums, happy to devour slices of meat, fish, the corpuscles of small insects. They can be fed pieces of fresh liver, crickets, moths, mealworms. Excellent for feeding food, which is sold in pet stores to feed the aquarium fish. Crabs are often prepared as a special nutritious food. It consists of dried nettles, red bell peppers in powder, which add calcium glycerophosphate in tablets. The ingredients are mixed into a thick omelet and offered to a colorful pet. Additionally add squid meat, frozen or dried gammarius, mussels.
Crustaceans do not disdain fresh vegetables, fruits, both tropical and ordinary. Their diet can include young shoots of nettle, leaves of lettuce, dandelion, spinach greens. From vegetable dishes, cooked carrots, heat-treated peas, corn, slices of pumpkin, and pieces of Brussels sprouts will do.
Marble crab (Pachygrapsus marmoratus)
A rare type of crab listed in the Red List. It lives in the Black Sea and the Mediterranean, most often found in the coastal waters of Sochi and Abkhazia. It is a small crab with a carapace up to 10 cm wide, with a characteristic “marbled” coloration and long legs dotted with barbed hairs.
It eats food consisting of invertebrates and organic remains on the rocky bottom, occasionally goes ashore, and can do without water for a while.
Grass crab (Carcinus aestuarii)
It is found off the coast of the Black Sea and the Sea of Azov, as well as in many bodies of water in the Mediterranean Sea basin. It is a small crab with a carapace up to 8 cm wide, colored grass-green. It has small claws, so its defense is weak, and in case of danger, it runs away well sideways at a speed of up to 1 m/sec.
Gets food from an ambush, hunting mussels, shrimp, small gastropods, and fish fry. Eagerly eats carrion and algae in coastal lagoons and bays.
Sand crab (Xantho poressa)
This is a small crab with a carapace up to 4.2 cm wide. It is colored grayish-green with dark speckles, sometimes with a blue or purple tint. It feeds on small bottom invertebrates and decomposed organic matter.
Is found off the coast of Crimea and the Caucasus, can be found in the Mediterranean Sea and the Canary Islands. The sand crab is extremely slow, rarely goes deeper than 15 m, preferring shallow water with gravel or sandy bottom.
Chinese mitten crab (Eriocheir sinensis)
Extremely unpretentious species originally lived only in the Yellow Sea, but at the beginning of the 20th century with the ballast water accidentally came to Europe, and today can be found even in the Volga and Lake Onega. It feeds on everything it finds on the bottom: mollusks, fish remains, and algae.
It has a carapace up to 7 cm wide and legs densely packed with hairs. Despite its diminutive size is considered a dangerous invasive species, a carrier of crayfish plague, and a human parasite – the pneumonic catfish.
Blue crab (Callinectes sapidus)
The blue crab, a native of the Atlantic coast, appeared in European waters in the early 20th century and today lives in the North, Baltic, Mediterranean, and Adriatic Seas. The carapace, up to 20 cm wide, is brown, gray, greenish, or bluish, with wide (to 8 cm) orange spines on each side.
Occurs at depths of up to 36 m and competes quite aggressively for food with other crayfish. Eats everything crabs eat: mollusks, small fish, worms, sea urchins, aquatic vegetation, and carrion. But unlike many relatives in the lack of food practices cannibalism.