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''Illex coindetii'', commonly known as the southern shortfin squid or broadtail shortfin squid, is a species of neritic squids in the family Ommastrephidae. They are found in the Mediterranean Sea and on both sides of the north Atlantic Ocean. ==Description== Mature specimens of ''Illex coindetii'' from different populations can vary significantly in both size and form. They are sexually dimorphic, with females being typically larger than males. The maximum recorded mantle length is in males and in females. These unusually large specimens, however, are not typical of the species.〔 The average mantle length is between in males and in females.〔 The eight arms bear two rows of suckers with teeth. In males, the longest of the arms is about 55 to 90% of the total mantle length, while it is 48 to 57% in females.〔 The tentacles have eight longitudinal rows of suckers on the dactylus of the tentacular clubs. The largest middle suckers on the tip are also notched on the rim farthest from the body or all around.〔 In males, the fourth left or right arm develops into a secondary sexual organ known as the hectocotylus. It is of equal length or shorter than the undeveloped opposite arm and of the same diameter.〔 The suckers on the distal third of the hectoctylus are lost and replaced with lamella-like flaps and conical papillae.〔 The upper part of the beak (rostrum) has a long and robust hood, smooth shoulder and short wings. The lower beak has a straight and long jaw edge and wide and long wings with no lobes.〔 The mantle is cylindrical with a width 15 to 25% of the mantle length.〔 It is widest in the front region except in gravid females. The funnel–mantle locking apparatus (cartilaginous structure connecting the funnel to the mantle) is T-shaped, a characteristic of all ommastrephid squids. The funnel groove (depression on the bottom front part of the mantle where the funnel rests) is smooth and lacks foveola (pockets of skin found in ommastrephid squids of the subfamily Ommastrephinae). The fins are rhomboidal in shape, with a width of around 45 to 60% of the mantle length.〔 Like other members of the genus, ''Illex coindetii'' lacks photophores (bioluminescent structures). 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「Illex coindetii」の詳細全文を読む スポンサード リンク
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