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Sunday, August 23, 2009

Lobster

Clawed lobsters compose a kinsfolk (Nephropidae, sometimes also Homaridae) of large marine crustaceans. Lobsters are economically important as seafood, forming the basis of a global business that nets US$31.8 billion in change annually.

Though individual different groups of crustaceans are famous as \"lobsters,\" the armed lobsters are most often associated with the name. They are also revered for their taste. Clawed lobsters are not closely related to spiny lobsters or slipper lobsters, which have no claws (chelae), or squat lobsters. The closest relatives of armed lobsters are the reef lobster Enoplometopus and the threesome families of freshwater crayfish.

Lobsters are institute in all the oceans of the world. They springy on rocky, sandy, or turbid bottoms from the shoreline to beyond the edge of the transcontinental shelf. They generally springy singly in crevices or in burrows under rocks.

They are invertebrates, with a hard conserving exoskeleton. Like most arthropods, lobsters must molt in order to grow, leaving them undefendable during this time. During the molting process, several species haw experience a modify in color. Lobsters hit 10 legs, with the face ones adapted to claws.

As arthropods, lobsters hit not achieved the nervous grouping utilization of cepholopod molluscs, nor do they hit the advantages of extraordinary eyesight. They do however, exhibit threesome important evolutionary advances that hit led to their great success: an exoskeleton: a strong, lightweight, form-fitted outside covering and support, striated muscle: a quick, strong, lightweight form of muscle that makes rapid shitting and flight possible, and articulation: the knowledge to bend appendeges at limited points.

Lobsters typically eat live food, consisting of fish, mollusks, other crustaceans, worms, and some plant life. Occasionally, they module scavenge if necessary, and haw resort to cannibalism in captivity; however, this has not been observed in the wild. Although lobster wound has been found in the stomachs of lobsters, this is because lobsters module eat their drop wound after molting. Lobsters acquire throughout their lives and it is not unusual for a lobster to live for more than 100 years. One such 100 year older lobster was donated to the Huntsman serviceman Science Center in St. Andrews, New Brunswick. In fact, lobsters haw show \"negligible senescence\", in that they crapper effectively live indefinitely, barring injury, disease, capture, etc. They crapper thus accomplish impressive sizes. According to the Guinness World Records, the largest lobster was caught in Nova Scotia, Canada, and weighed 20.15 kg (44.4 lb).

Although armed lobsters, same most other arthropods, are mostly bilaterally symmetrical, they often possess unequal, specialized claws, same the king crab. A freshly caught lobster module have a claw which is full and fleshy, not atrophied. The morphology of the lobster includes the cephalothorax which is the nous fused with the thorax, both of which are covered by the carapace, of chitinous composition, and the abdomen. The lobster's nous consists of antennae, antennules, mandibles, the first and ordinal maxillae, and the first, second, and ordinal maxillipeds. Because a lobster lives in a murky environment at the bottom of the ocean, its vision is poor and it mostly uses its antennae as sensors. Studies have shown that the lobster eye is bacilliform with a reflective structure atop a convex retina. In contrast, most complex eyes use refractive ray concentrators (lenses) and a cotyloid retina. The abdomen of the lobster includes swimmerets and its tail is imperturbable of uropods and the telson.

Lobsters, like snails and spiders, have blue murder cod to the proximity of haemocyanin, which contains copper. (In contrast, mammals and many another animals, have red murder cod to the proximity of haemoglobin, which contains iron.) Inside lobsters is a naif goopy center titled tomalley, which serves as the hepatopancreas, fulfilling the functions of both liver and pancreas.

In general, lobsters are 25 cm to 50 cm daylong ( 10 to 20 inches ) and move slowly by walking on the bottom of the sea floor. However, when they flee, they swim backwards quickly by curling and uncurling their abdomen. A speed of five meters per second (about 11 mph) has been recorded. This is known as the caridoid escape reaction.