分類 / 名前
共通名の | 類義語 | Catalog of Fishes(部類, 種) | ITIS | CoL | WoRMS | Cloffa
板鰓亜鋼(サメとエイ類) (sharks and rays) >
Squaliformes (Sleeper and dogfish sharks) >
Dalatiidae (Sleeper sharks)
Etymology: Isistius: Etymology not explained, probably iso-, from isos (Gr.), equal; istius, from histion (Gr.), sail (i.e., dorsal fin), referring to its two similarly shaped and sized (and posterior) dorsal fins, a character Gill used to diagnose genus. José I. Castro, The Sharks of North America (Oxford University Press, 2011), suggests name may allude to the Egyptian goddess Isis, represented in statuary with her head veiled, or to the dark collar encircling throat of I. brasiliensis, “which could also suggest a veil over the head” (p. 145). This interpretation is rejected by the fact that Gill often used “istius” in the names of several genera distinguished (at least in part) by their dorsal fins (Acanthistius, Brachyistius, Caristius, Dichistius, Goniistius, Iniistius, Micromesistius, Nematistius) (See ETYFish); brasiliensis: -ensis, Latin suffix denoting place: off the coast of Brazil, type locality (See ETYFish).
More on authors: Quoy & Gaimard.
環境：環境 / 気候帯 / 深さの範囲 / 分布範囲
生態学
海 深海浮遊性; 海洋回遊性 (Ref. 51243); 深さの範囲 0 - 3700 m (Ref. 55584), usually 0 - 1000 m (Ref. 89423). Deep-water; 35°N - 47°S, 180°W - 180°E
Western Atlantic: Bahamas and southern Brazil. Eastern Atlantic: Cape Verde, Guinea to Sierra Leone, southern Angola and South Africa, including Ascension Island. Indo-Pacific: Mauritius to New Guinea, Lord Howe Island, and New Zealand (Ref. 26346), north to Japan and east to the Hawaiian Islands. Eastern Pacific: Easter Island (Ref. 9068) and the Galapagos.
初回成熟時の長さ / サイズ / 重さ / 年齢
成熟: Lm 41.0, range 38 - 44 cm
Max length : 42.0 cm TL オス/雌雄の選別がない; (Ref. 48844); 56.0 cm TL (female)
背面の脊椎 (合計) : 0; 肛門の骨: 0; 脊つい: 81 - 89. The cookiecutter shark Isistius brasiliensis is distinctive for the prominent dark collar marking around its throat, large nearly symmetrical caudal fin with a long ventral lobe over 2/3 length of dorsal caudal margin, and moderately large lower teeth in 25-32 rows. Eyes set anterior of head but sufficiently far back to lack an extensive anterior binocular field. Pectoral fins subquadrate; pelvic fins larger than dorsal fins (Ref.247). Tooth count: 30-37/25-31. Vertebral count: 81-89. Spiral valve count: 8-10 (Ref. 48844). Dark brown dorsally, paler ventrally except for blackish band across throat; tips of caudal lobe blackish (Ref. 6577). As with the other member of the genus Isistius , it has a characteristic small cigar-shaped body with two small close-set spineless dorsal fins far posterior on back, no anal fin, huge, triangular-cusped teeth without blades, short, bulbous snout and a unique suctorial lips (Ref. 247).
Body shape (shape guide): elongated.
Oceanic species (Ref. 247). Epi- to bathypelagic at 1-3500 m (Ref. 58302). Makes diurnal vertical migrations from below 1,000 m in the day to or near the surface at night (Ref. 6871, 58302). Travels long vertical distances in excess of 2,000 to 3,000 m on a diel cycle (Ref. 247). Feeds free-living deepwater prey such as large squid, gonostomatids, crustaceans but is also a facultative ectoparasite on larger pelagic animals such as wahoo, tuna, billfishes, and cetaceans (Ref. 247). Ovoviviparous (Ref. 205), with 6-12 young per litter (Ref. 48844). The cookiecutter shark has specialized suctorial lips and a strongly modified pharynx that allow it to attach to the sides of it prey (Ref. 247). It then drives its saw-like lower dentition into the skin and flesh of its victim, twists about to cut out a conical plug of flesh, then pull free with the plug cradled by its scoop-like lower jaw and held by the hook-like upper teeth (Ref. 247). Teeth are shed as a complete unit; the lower teeth are swallowed, perhaps to maintain sufficient calcium levels in its body (Ref. 247). Interconnection at the bases of individual tooth allows a whole row of teeth to move if one tooth is touched. This shark is reported to radiate light for as long as three hours after its death. Not dangerous to people because of its small size and habitat preferences (Ref. 247).
ライフサイクルと交尾行動
成熟 | 繁殖 | 放精 | 卵 | 生産力 | 幼生
Presumably ovoviviparous; 6 or 7 large eggs have been found in ovaries (Ref. 247). Distinct pairing with embrace (Ref. 205). Viviparous, without a yolk sac placenta, 6-12 young per litter. Males mature at about 36 cm, with a maximum length of 42 cm; females mature at 39 cm, with a maximum length of 56 cm. Size at birth is unknown. (Ref. 48844).
Compagno, L.J.V., 1984. FAO Species Catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. Part 1 - Hexanchiformes to Lamniformes. FAO Fish. Synop. 125(4/1):1-249. Rome, FAO. (Ref. 247)
IUCNのレッドリストの状況は (Ref. 130435: Version 2025-2 (Global))
人間の用途
水産業: 少数商業の
用具
特記事項
XMLをダウンロードして下さい
インターネットの情報源
モデルに基づく推定値
好ましい温度 (参照
123201): 3.1 - 9.7, mean 4.8 °C (based on 2327 cells).
系統多様性指数 (参照
82804): PD
50 = 0.7510 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00309 (0.00143 - 0.00669), b=3.14 (2.94 - 3.34), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref.
93245).
栄養段階 (参照
69278): 4.3 ±0.3 se; based on diet studies.
回復力 (参照
120179): 非常に低い, １４年以上の倍増期間の最小個体群 (Fec = 6).
漁業の脆弱性 (Ref.
59153): Moderate vulnerability (42 of 100).
🛈
