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''Callinectes sapidus'' (from the Greek ' = "beautiful", ' = "swimmer", and Latin ' = "savory"), the blue crab, Atlantic blue crab, or regionally as the Chesapeake blue crab, is a species of crab native to the waters of the western Atlantic Ocean and the Gulf of Mexico, and introduced internationally. ''C. sapidus'' is of significant culinary and economic importance in the United States, particularly in Louisiana, the Chesapeake Bay, and New Jersey. It is the Maryland state crustacean and is the state's largest commercial fishery.〔(【引用サイトリンク】title=Maryland State Crustacean )〕 ==Description== ''Callinectes sapidus'' is a decapod crab of the swimming crab family Portunidae. The genus ''Callinectes'' is distinguished from other portunid crabs by the lack of an internal spine on the carpus (the middle segment of the claw), as well as by the T-shape of the male abdomen. Blue crabs may grow to a carapace width of . ''C. sapidus'' individuals exhibit sexual dimorphism. Males and females are easily distinguished by the shape of the abdomen (known as the "apron") and by color differences in the chelipeds, or claws. The abdomen is long and slender in males, but wide and rounded in mature females. A popular mnemonic is that the male's apron is shaped like the Washington Monument, while the mature female's resembles the dome of the United States Capitol. Claw color differences are more subtle than apron shape. The immovable, fixed finger of the claws in males is blue with red tips, while females have orange coloration with purple tips. A female's abdomen changes as it matures: an immature female has a triangular-shaped abdomen, whereas a mature female's is rounded. Other species of ''Callinectes'' may be easily confused with ''C. sapidus'' because of overlapping ranges and similar morphology. One species is the lesser blue crab (''C. similis''). It is found further offshore than the common blue crab, and has a smoother granulated carapace. Males of the lesser blue crab also have mottled white coloration on the swimming legs, and females have areas of violet coloration on the internal surfaces of the claws.〔(【引用サイトリンク】url=http://www.sms.si.edu/irlspec/Callinectes_similis.htm )〕 ''C. sapidus'' can be distinguished from another related species found within its range, ''C. ornatus'', by number of frontal teeth on the carapace. ''C. sapidus'' has four, while ''C. ornatus'' has six. The crab's blue hue stems from a number of pigments in the shell, including alpha-crustacyanin, which interacts with a red pigment, astaxanthin, to form a greenish-blue coloration. When the crab is cooked, the alpha-crustacyanin breaks down, leaving only the astaxanthin, which turns the crab to a red-orange or a hot pink color.〔(【引用サイトリンク】publisher=Blue Crab Archives )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Callinectes sapidus」の詳細全文を読む スポンサード リンク
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