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The Chiroteuthidae are a family of deep-sea squid, generally small to medium in size, rather soft and gelatinous, and slow moving. They are found in most temperate and tropical oceans, but are known primarily from the North Atlantic, North Pacific, and Indo-Pacific. The family is represented by approximately 12 species and four subspecies in four genera, two of which are monotypic. They are sometimes known collectively as whip-lash squid, but this common name is also applied to the Mastigoteuthidae, which are sometimes treated as a subfamily (Mastigoteuthinae) of Chiroteuthidae. The monotypic genus ''Grimalditeuthis'' was once (and may still be) given its own family, Grimalditeuthidae. Generally speaking, chiroteuthids are not well represented by described specimens, because they are so often damaged during capture. == Description == The Chiroteuthidae are most notable for their unique paralarval stage, known as the doratopsis stage. Although morphology varies greatly within the family, the Chiroteuthidae are distinguished by their extremely elongated bodies and (in most species) tentacles; the latter may be up to four times the mantle length in ''Asperoteuthis acanthoderma''. The head is atop an elongated neck and the brachial pillar is well-developed, the eyes are large; in some ''Planctoteuthis'' and all ''Chiroteuthis'' species, the fourth pair of arms possess both greater girth and length than the other arms. The fragile, gelatinous body is conical and the neck cylindrical; the fins range from oval to elliptical, about 50% of the mantle length. The suckers of the arms occur in two series, and those of the clubs in four (but are absent in subadult ''Grimalditeuthis'' and absent proximally in ''Asperoteuthis''). The club is elongated and—with the exception of ''Planctoteuthis'' species—is subdivided by symmetrical, protective membranes into two or three parts. The funnel locking apparatus is oval; its cartilage is ear-shaped with one or two projections and a central depression. In ''Grilmalditeuthis'', the apparatus is fused (but nuchal articulation is free); in ''Chiroteuthis'' both the tragus and antitragus are present, while in ''Planctoteuthis'', only the antitragus is present. Also absent in ''Planctoteuthis'' are the funnel valve, tentacle pads, and distal suckers on the fourth arms. Some species (excluding ''Planctoteuthis'') are bioluminescent, with photophores (light-producing organs) variably present on the inner surface of the ventral arms, on the ventral surface of the eyes (one to three patches or bands), on the ink sac, and near the club terminus. A number of chambers containing ammonium chloride are contained within the arms, head, and mantle. With a lower density than the surrounding seawater, the ammonium chloride helps chiroteuthids to conserve energy reserved for swimming by maintaining the body's neutral buoyancy. The eyelid sinus is indistinct, occpital folds are absent, and long stalks support the olfactory papillae. The largest species reach a mantle length of about 78 cm. Body coloration is typically beige to sepia, but ''Asperoteuthis acanthoderma'' is noted for its deep violet color. 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「Chiroteuthidae」の詳細全文を読む スポンサード リンク
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