Blue crab: photo of a crustacean with blue limbs. Blue American crabs-invaders survive our Black Sea crabs in the Crimea Blue Crab
intermediate ranks
Callinectes sapidus Rathbun, 1896
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Description
Natural enemies
- other barnacles.
Reproduction and development
The blue crab becomes sexually mature between 12 and 18 months of age. Females mate only once a year, immediately after molting, while males mate more often.
Like all crustaceans, the blue crab molts periodically throughout its life. After molting, the female's carapace is soft for a short time. The male uses this time to mate with the female. The female is quite capable for a long time store male sperm. She spawns approximately 2 months after mating. The clutch consists of 2 million eggs. Spawning begins in December and ends in October, with a peak in spring and summer. After the female lays her eggs, the eggs are fertilized by stored sperm and attached to tiny hairs on her abdominal legs.
The incubation period is approximately 14 days. Over the course of 2 months, planktonic larvae go through 8 stages before they acquire the appearance of crabs.
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Notes
Literature
- Diverse: Grzimeks Tierleben. Niedere Tiere. 1.Bd. Deutscher Taschenbuch Verlag GmbH & Co.KG, München Oktober 1993
- Hans-Echhard Gruner, Hans-Joachim Hannemann und Gerhard Hartwich, Urania Tierreich, 7 Bde., Wirbellose Tiere, Urania, Freiburg, 1994
Excerpt characterizing the Blue Crab
A few days later, my favorite black maid Kay (at that time it was very fashionable to have black servants in rich houses) reported that “His Eminence, the Cardinal, is waiting for me in the pink drawing room.” And I felt that something would happen right now...I was wearing a light yellow silk dress and knew that this color suited me very well. But if there was one person in the world in front of whom I did not want to look attractive, it was certainly Caraffa. But there was no time left to change clothes, and I had to go out that way.
He waited, calmly leaning on the back of his chair, studying some old manuscript, of which there were a countless number in our house. I put on a pleasant smile and went down to the living room. Seeing me, for some reason Karaffa froze, without uttering a word. The silence dragged on, and it seemed to me that the cardinal was about to hear my frightened heart beating treacherously loudly... But finally, his enthusiastic voice was heard, hoarse voice:
– You are amazing, Madonna Isidora! Even this sunny morning is playing next to you!
– I never thought that cardinals were allowed to compliment ladies! – with the greatest effort, continuing to smile, I squeezed out.
- Cardinals are people too, Madonna, and they know how to distinguish beauty from simplicity... And where is your wonderful daughter? Will I be able to enjoy double beauty today?
– She is not in Venice, Your Eminence. She and her father went to Florence to visit her sick cousin.
- As far as I know, in this moment there are no sick people in your family. Who fell ill so suddenly, Madonna Isidora? – there was an undisguised threat in his voice...
Caraffa began to play openly. And I had no choice but to face the danger face to face...
– What do you want from me, Your Eminence? Wouldn't it be easier to say it directly, saving us both from this unnecessary, cheap game? We are enough smart people so that, even with differences in views, they can respect each other.
My legs were giving way from horror, but for some reason Caraffa didn’t notice this. He glared at my face with a flaming gaze, not answering and not noticing anything around. I couldn’t understand what was happening, and this whole dangerous comedy frightened me more and more... But then something completely unexpected happened, something completely outside the usual framework... Caraffa came very close to me, that’s all also, without taking his burning eyes off, and almost without breathing, he whispered:
– You cannot be from God... You are too beautiful! You are a witch!!! A woman has no right to be so beautiful! You are from the Devil!..
And turning around, he rushed out of the house without looking back, as if Satan himself was chasing him... I stood in complete shock, still expecting to hear his steps, but nothing happened. Gradually coming to my senses, and finally managing to relax my stiff body, I took a deep breath and... lost consciousness. I woke up on the bed, drinking hot wine from the hands of my dear maid Kei. But immediately, remembering what had happened, she jumped to her feet and began to rush around the room, not having any idea what to do... Time passed, and she had to do something, come up with something in order to somehow protect herself and your family from this two-legged monster. I knew for sure that now all the games were over, that the war had begun. But our forces, to my great regret, were very, very unequal... Naturally, I could defeat him in my own way... I could even simply stop his bloodthirsty heart. And all these horrors would end immediately. But the fact is that, even at thirty-six years old, I was still too pure and kind to kill... I never took a life, on the contrary, I very often gave it back. And even this scary person, what Caraffa was, could not execute yet...
The next morning there was a loud knock on the door. My heart has stopped. I knew - it was the Inquisition... They took me away, accusing me of “verbalism and witchcraft, stupefying honest citizens with false predictions and heresy”... That was the end.
The room they put me in was very damp and dark, but for some reason it seemed to me that I wouldn’t stay in it for long. At noon Caraffa came...
– Oh, I beg your pardon, Madonna Isidora, you were given someone else’s room. This is not for you, of course.
– What is all this game for, monsignor? – I asked, proudly (as it seemed to me), raising my head. “I would prefer simply the truth, and I would like to know what I am really accused of.” My family, as you know, is very respected and loved in Venice, and it would be better for you if the accusations were based on truth.
Caraffa would never know how much effort it took me to look proud then!.. I understood perfectly well that hardly anyone or anything could help me. But I couldn't let him see my fear. And so she continued, trying to bring him out of that calmly ironic state, which apparently was his kind of defense. And which I absolutely couldn’t stand.
The blue crab (Latin: Callinectes sapidus) belongs to the family of Swimming Crab (Latin: Portunidae). This crustacean is of great commercial importance, and its annual catch exceeds 28,000 tons. His meat with late XIX centuries, it is considered an exquisite delicacy, so the population is steadily decreasing.
Over the past two decades, it has decreased from approximately 900 to 300 million individuals. In the United States alone, more than 4,500 companies receive a license to catch blue crab every year.
Spreading
The natural habitat of the blue crab is the western coast of the Atlantic Ocean from the Cape Cod Peninsula, located in the northeastern United States to Argentina and southern Uruguay, including all coastal zone Gulf of Mexico. Together with the ballast waters of transport ships, it ended up in the Mediterranean Sea at the beginning of the 20th century.
In 1901, the first specimens of blue crab were caught off the coast of the French port city of Rochefort, 15 km from the Bay of Biscay. It was later discovered in Holland (1932), Denmark (1951), Germany (1964) and near the eastern borders of England (1975).
Since the late 90s, this species has spread throughout the Adriatic and reached the Black Sea. In Turkey, the blue crab has taken root well in the vicinity of the city of Dalyan and has become a local attraction. The largest populations are found in the Gulf of Mexico and the eastern United States.
Behavior
Blue crabs live primarily in the mouths of rivers and other coastal bodies of water up to 36 m deep and live on sandy or muddy soil. In winter they go into deeper waters. Adult animals tolerate lower temperatures environment up to 10°C, and juveniles feel comfortable within 15°-30°C. Larvae, unlike their older counterparts, react poorly to a decrease in water salinity below 20 PSU.
Hunting is carried out mainly from ambush. The crab burrows into the ground or hides in the thick of aquatic vegetation, patiently waiting for approaching prey. It is a food competitor to many crustaceans, so it is extremely aggressive towards representatives of other species.
The basis of the diet is small fish, bivalves, worms and plants. Callinectes sapidus is omnivorous and not too picky about food. It can feed on carrion, and when there is a shortage of food, it turns to cannibalism. Small and sick individuals are eaten first. Its main natural enemies are considered sea turtles, herons, gulls and fish from the Gorbylev family (Sciaenidae).
Reproduction
Blue crabs breed only in the warm season, when the water is warm enough and the females are molting. During this period, they are soft and defenseless, which is what the males take advantage of. The female mates only once, but the males can do this multiple times. Mating occurs in shallow water in river estuaries.
We must pay tribute to the newly made spouse. For almost a week, he courageously guards his beloved from omnipresent competitors and patiently waits until she acquires a new hard shell.
Fertilized females carry spermatophores in their bodies for up to one year.
Egg throwing occurs several times, most often 2-11 months after mating, from December to October, mainly in spring and summer. One female is capable of producing more than 2 million eggs per season.
Incubation lasts about 14 days. Larvae are born in salty sea waters and within two months they go through 8 stages of development, after which they begin to resemble their older brothers. They reach sexual maturity at 12-18 months. By this age, only 2-3 animals from one batch of larvae survive.
Description
The length of the carapace is 7-10 cm and the width is 16-20 cm. The weight of adult individuals reaches 0.4-0.95 kg. The back is colored dark brownish, gray or greenish-blue and is armed with sharp spines along the front edge of the shell. The abdomen and legs are whitish.
Males have blue claws, while females have light red claws. There are 5 pairs of legs. During evolution, the front pair was transformed into powerful claws, used for cutting prey and self-defense. The fifth pair of legs resembles oars and is used for locomotion. aquatic environment. All lost limbs are able to quickly restore their previous shape.
Short-set compound eyes are located on the head of the carapace. Between them are small and sensitive antennae.
Blue crab in natural conditions lives 2-4 years.
Description
- sea acorns (Balanidae)
- other barnacles (Cirripedia)
- nematodes (Nematoda)
- trematodes (Trematoda)
Reproduction and development
The blue crab becomes sexually mature between 12 and 18 months of age. Females mate only once a year, immediately after molting, while males mate more often.
Like all crustaceans, the blue crab molts periodically throughout its life. After molting, the female's carapace is soft for a short time. The male uses this time to mate with the female. The female is able to store the male's sperm for quite a long time.
The female spawns approximately 2-9 months after mating. The clutch consists of 2 million eggs. Spawning begins in December and ends in October, with a peak in spring and summer. After the female lays her eggs, the eggs are fertilized by stored sperm and attached to tiny hairs on her abdominal legs.
The incubation period is approximately 14 days. Over the course of 2 months, planktonic larvae go through 8 stages before they acquire the appearance of crabs.
Notes
Literature
- Diverse: Grzimeks Tierleben. Niedere Tiere. 1.Bd. Deutscher Taschenbuch Verlag GmbH & Co.KG, München Oktober 1993
- Hans-Echhard Gruner, Hans-Joachim Hannemann und Gerhard Hartwich, Urania Tierreich, 7 Bde., Wirbellose Tiere, Urania, Freiburg, 1994
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See what “Blue Crab” is in other dictionaries:
- "Tintin on Far East"(French: Les aventures de Tintin, reporter, en Extrême Orient) or "The Blue Lotus" (Le Lotus bleu) is the fifth album of Hergé's classic comics about the adventures of Tintin (1936). The continuation of "Cigar of the Pharaoh", the action of which is ... Wikipedia
The original home of the blue crab is atlantic coast Northern and South America. This species was first discovered in Europe in 1900. Today it can be found in vast areas of the Baltic and North Seas. It is also found in the Mediterranean and Adriatic seas.
The blue crab lives primarily in river mouths and shallow waters at depths of up to 36 m, deeper in winter. It prefers muddy and sandy bottoms.
Wendy Kaveney, CC BY-SA 3.0Young crabs need a water temperature of 15 to 30 °C. Adult animals can tolerate water temperatures up to 10°C. Larvae, unlike young and adult animals, are demanding of the average salinity value, not tolerating values below 20 percent.
Description
The carapace of the blue crab reaches a width of 17.8-20 cm and a length of 7.5-10.2 cm. Males are larger than females. The weight of sexually mature animals ranges from 0.45 to 0.90 kg. The dorsal shell is dark brown, grayish, greenish or bluish-green in color and has orange spines up to 8 cm wide on each side. The lower limbs and abdomen are whitish in color.
The claws have different color shades depending on gender. The tops of the claws of males are bluish, those of females are reddish.
The blue crab has five pairs of thoracic limbs. The front pair of limbs are transformed into two strong claws of different sizes. The massive breaking claw is used to split shells, while the smaller claw is used by the crab to tear open soft tissue and send food into the mouth. The fifth pair of limbs is shaped like a kayak oar and is used for swimming. Blue crabs are capable of throwing away their claws when threatened. The crab can then restore lost limbs.
Compounded eyes on short stalks are located directly below the anterior edge of the carapace on the head. Between the eyes there are two pairs of short and thin antennae.
The lifespan of a blue crab is approximately 2 to 4 years.
Lifestyle
After mating, the females return to shallow waters salty waters, while males remain in river mouths.
Most of the time, crabs hide in mud or sea grass to watch for their prey or protect themselves from enemies. The blue crab is quite aggressive compared to other species.
Photo gallery
Helpful information
Blue crab (lat. Callinectes sapidus)
Nutrition
The blue crab competes with other crustaceans for food. This is an omnivore. Its food spectrum includes molluscs such as mussels, young crustaceans, fish, worms, as well as plants. Does not disdain to feed on carrion. When there is a shortage of food, the animal is prone to cannibalism.
Natural enemies
TO natural enemies blue crabs include red croaker, common croaker, American herring gull, different kinds herons, as well as sea turtles.
Blue crab is considered a delicacy and is caught in large quantities.
Reproduction and development
The blue crab becomes sexually mature between 12 and 18 months of age. Females mate only once a year, immediately after molting, while males mate more often.
Like all crustaceans, the blue crab molts periodically throughout its life. After molting, the female's carapace is soft for a short time. The female spawns approximately 2 months after mating. The clutch consists of 2 million eggs. Spawning begins in December and ends in October.
The incubation period is approximately 14 days. Over the course of 2 months, planktonic larvae go through 8 stages before they acquire the appearance of crabs.
This is definitely not easy. To the Black Sea from North America brought a blue crab, which became one of the new species sea creatures and is now actively reproducing. These animals can displace the original inhabitants of the coast - the Black Sea crabs. Natalia Milchakova, head of the phytoresources laboratory at the Institute of Marine Biological Research of the Russian Academy of Sciences, explained this by saying that pollution and deterioration in environmental quality have also changed the population of the ecosystem.
“In Koktebel Bay in 2010–2011, a blue crab was registered right on the piers, which is an invader in the Black Sea,” Milchakova clarified.
She noted that these animals could cause serious damage to the inhabitants of the Black Sea if they begin to live, reproduce and increase the population. Local divers have encountered small specimens of blue crabs, and there is a danger that the population will take root there, the expert said.
Blue crab
“This is dangerous because the blue crab is omnivorous and it can undermine the food supply of our crabs, which are listed in the Red Book of the Republic of Crimea,” Milchakova said.
According to her, the population of the brown algae cystoseira, which is the main link in the production of oxygen, as well as the red-listed sea grass zoster, in which the grass crab lives, are also under threat.
"This is the result anthropogenic influence, which wastewater inevitably leads to"
The photo shows our Black Sea stone crab. Very alarming and sad news, this year I noticed that there are fewer crabs than last year.
We need to do something about this American occupier, we need to catch it and destroy it (eat it if it is edible). If I see this occupier, I will definitely catch him, and I wish our stone ones victory!
