Shrimp are crustaceans with elongated bodies and a primarily swimming mode of locomotion. Under a broader definition, shrimp may be synonymous with prawn, covering stalk-eyed swimming crustacean with long narrow muscular tails long antennae and slender legs. Any small crustacean which resembles a shrimp tends to be called one. They swim forward by paddling with swimmerets on the underside of their abdomens, although their escape response is typically repeated flicks with the tail driving them back very quickly. Crabs and lobsters have strong walking legs, whereas shrimp have thin, fragile legs which they use primarily for perching. Shrimp are widespread and abundant. There are thousands of species adapted to a wide range of habitats. They can be found feeding near the seafloor on most coasts and estuaries, as well as in rivers and lakes. To escape predators, some species flip off the seafloor and dive into the sediment. They usually live from one to seven years. Shrimp are often solitary, though they can form large schools during the spawning season.
They play important roles in the food chain and are an important food source for larger animals ranging from fish to whales. The muscular tails of many shrimp are edible to humans, and they are widely caught and farmed for human consumption.
Crabs are generally covered with a thick exoskeleton, composed primarily of highly mineralized chitin, and armed with a single pair of claws. Crabs are found in all of the world’s oceans, while many crabs live in freshwater and on land, particularly in the tropical regions Crabs vary in size from the pea crab, a few millimetres wide, to the Japanese spider crab, with a leg span up to 4 m (13 ft). Crab is a great source of two beneficial long-chain omega-3 fatty acids, EPA and DHA, which have anti-inflammatory properties. Research suggests they help lower blood pressure, protect against heart disease, improve cognitive function, and reduce conditions such as psoriasis and ulcerative colitis.
Types of crab
- Dungeness Crab -The carapaces of Dungeness crabs are oval-shaped and range in colour from a yellow-brown to purple.
- Stone Crab- Stone crabs are usually brownish red with grey spots and their undersides are a tan colour.
- Snow Crab- It is found along the east coast of the U.S., living among rocks and in deep water. Its spindly legs make it resemble a spider, and is also known as “spider crab.”
- King Crab-This giant crab is also often called “Alaskan King Crab,” “Japanese crab,” and “Russian crab” due to its size, which can reach up to 25 pounds and measure up to 10 feet. It may be large, but only about one-fourth is edible, primarily the legs and claws. Only males are harvested. The delicately flavoured meat is snowy white with a bright red outer edge.
- Blue Crab-it is indeed a beautiful blue-green colour. The most prolific species on the east coast of the U.S., they range in size from 3 1/2 inches up to 5 1/2 inches or more on the market. Though their blue colour is their most common identifying feature, these crabs do turn the traditional reddish colour when cooked.
Lobsters have long bodies with muscular tails and live in crevices or burrows on the seafloor. Three of their five pairs of legs have claws, including the first pair, which are usually much larger than the others. Unlike with most fisheries, there aren’t any commercial farms to cheaply provide a lot of lobsters. Lobster farming is difficult: The crustaceans grow slowly, eat a lot, and are susceptible to a very contagious disease, and their eggs are difficult to raise. Lobsters and other shellfish have harmful bacteria naturally present in their flesh. Once the lobster is dead, these bacteria can rapidly multiply and release toxins that may not be destroyed by cooking. You, therefore, minimise the chance of food poisoning by cooking the lobster alive.