Sharks
Pelagic Thresher Shark
Alopias pelagicus · Cartilaginous fish, family Alopiidae
The pelagic thresher looks like a shark designed by a calligrapher: huge liquid eyes, a small mouth, metallic lavender-gray flanks, and a tail that streams behind it in an impossible ribbon. At dawn over Monad Shoal, divers kneel behind rope lines in blue half-light until one rises from the deep and begins its slow carousel around a cleaning station, tail arcing with every turn. It is among diving's most graceful sights and one of its best-managed: local rules on distance and lights have kept the sharks coming for two decades. Elsewhere the species exists mostly as bycatch statistics, which the Endangered listing reflects.
أين ومتى تراها
"مقيم" تعني أن معظم الغطسات في هذه الوجهة ستُمكّنك من مشاهدتها؛ "موسمي" تعني أنها متواجدة بشكل موثوق خلال الأشهر المذكورة؛ أي شيء آخر فهو مكسب غير متوقع، وليس شيئًا يُعتمد عليه في التخطيط.
| الوجهة | الموثوقية | الأشهر | ملاحظات |
|---|---|---|---|
| MalapascuaPhilippines | Resident: seen on most dives | طوال العام | |
| Brothers, Daedalus & St John'sEgypt | Occasional | طوال العام | |
| Marsa Alam & the Deep SouthEgypt | Occasional | طوال العام |
أفضل شهر، في لمحة
فهمها
الموئل: Open ocean and deep seamount flanks; rises to shallow cleaning stations at dawn, one of the few predictable windows into its world
النطاق: Indo-Pacific pelagic waters from the Red Sea and East Africa to Mexico; the reliable diver encounters are at Philippine seamounts
السلوك: A shy, wide-eyed deep-water hunter that visits cleaning stations in the dim early morning, circling patiently while cleaner wrasses work its skin and gills. The tail-slap hunting technique, confirmed on video off Cebu, is unique theater: the shark lunges, brakes, and snaps its caudal fin overhead like a whip.
النظام الغذائي: Small schooling fish and squid, stunned with whip-cracks of the enormous tail before being picked off
الحجم: عادةً حوالي 3.0 m; موثَّق حتى عمق 3.8 m (total length; the scythe-shaped upper tail lobe accounts for roughly half of it).
كيف تتصرف في حضوره
Follow the Malapascua protocol that made these dives sustainable: stay behind the viewing lines, no flash where prohibited, minimal movement and noise, and let the shark control its circuit of the cleaning station.
الحفاظ على البيئة البحرية
Endangered: slow reproduction (usually two pups) collides with heavy longline and gillnet mortality across the Indo-Pacific. The Philippines' protection of its cleaning stations is a working model of encounter-based conservation.
المواقع المعروفة بها
المواقع المُبرزة رسَّمها محرّرونا لهذا النوع؛ والأرقام هي سجلات ظهور GBIF المُسجَّلة في نطاق نحو 5 كم من الموقع منذ عام 1990.
شاهد
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مقاطع الفيديو روابط مُضمَّنة لقنوات أصحابها. لا نستضيف شيئًا ونُشير إلى المصدر في كل الأحوال.