Blue crab photo and description of what it looks like and where the crustacean lives

Individuals of different sexes have differences among themselves:

Peculiarity	Female	Male
The location of the pores of the genital organs	Located at the beginning of the third pair of paws.	Located at the base of the fifth pair of paws.
The size	up to 30 cm.	about 20-25cm.
claws	Very strong.	Much weaker.
Pleopods	shortened.	elongated.

Content

Structure
Where do they live?
reproduction

Structure

Blue crabs have 5 pairs of legs and what distinguishes it from other similar individuals is the keel located on top. It has 4 more keels on the shell, but they are small and poorly defined. Pay attention to other structural features of the blue crab:

To protect against external negative impact, the head area and internal organs are covered with a special shell;

On the abdominal segments there is a flexible membrane that facilitates the process of movement;

For eating food, raking the bottom, digging 2-meter trenches in depth, the blue crayfish has powerful 2 claws located in front;

Fine hairs grow on pleopods, which serve as an element for attaching eggs;

Carapace with 2 large spines, but there are individuals strewn with small spines;

Rostrum pointed and slightly bent down, on the surface there are 2 spines and the same number of spines; the span of walking 8 paws is impressive;

Reduced 2 legs hide under the carapace;

The tentacles are large, perform tactile functions;

The spike is movable it branches into 2 segments at the very base of the antennae from the outside.

Where do they live?

The natural localization of blue crabs is considered to be the eastern and western Pacific, the Sea of Japan, the Sea of Okhotsk and the Bering Sea. The species prefers to live in water bodies with the following conditions:

The temperature regime of the sea in winter is from +1 to +2°C, in summer from +3 to a maximum of +7°C;

The depth of residence is at least 10 m, since only at such a depth is the required water temperature noted;

During hibernation, crabs descend even lower, up to 300-500 m down;

Soil type silt-sand.

These are the original biological features of the species, but over a long time, blue crabs have learned to adapt to any conditions, up to living near hot springs and fresh water.

Where do they meet:

Seas and oceans;

Dams;

deep wells;

swamps;

Streams and rivers;

reservoirs.

Accordingly, their main place of residence is the sea and the ocean, and a person launches crabs artificially into other bodies of water.

Blue crabs have an amazing ability increased vitality even during severe drought. It turns out that the arthropod can burrow into the deep layers of moist soil after the reservoir dries up and remain in a lethargic sleep for about 12 months, after which, when the water is filled, they easily come to life.

reproduction

The breeding method of blue crabs is distinguished by a double population. Namely, since the female spawns only once every couple of years, the female individuals breed in a year by generations. That is, one year one part of the females of the ocean, the next another. Thus, the larvae appear annually.

Peculiarities:

The period for throwing caviar is from the beginning of March to the first days of April;

The hatching time of the larvae is April and May;

The total time for the development of eggs is 13 months;

After fertilization, the eggs stick to the mother’s pleopods;

After 11 months, the development of the pelagic type begins, which lasts another 2 months;

After that, they are transformed into glaucotoe (this is the pre-fry stage) and unhook from the mother;

For 18-20 days they live in the near-bottom space, then they become full-fledged fry.

Preparation for mating is carried out in advance, therefore, even in autumn, females descend to a depth of about 120 m, and in December even deeper 200-400 m. This is where the males live in winter. After the onset of spring, the mating process begins.