Oceanic whitetip shark in Red Sea
The whitetip reef shark (Triaenodon obesus) is a species of requiem shark, in the family Carcharhinidae, and the only member of its genus.
A small shark usually not exceeding 1.6 m (5.2 ft) in length, this
species is easily recognizable by its slender body and short but broad
head, as well as tubular skin flaps beside the nostrils, oval eyes with vertical pupils, and white-tipped dorsal and caudal fins. One of the most common sharks found on Indo-Pacific coral reefs, the whitetip reef shark occurs as far west as South Africa and as far east as Central America. It is typically found on or near the bottom in clear water, at a depth of 8–40 m (26–131 ft).
A small shark usually not exceeding 1.6 m (5.2 ft) in length, this
species is easily recognizable by its slender body and short but broad
head, as well as tubular skin flaps beside the nostrils, oval eyes with vertical pupils, and white-tipped dorsal and caudal fins. One of the most common sharks found on Indo-Pacific coral reefs, the whitetip reef shark occurs as far west as South Africa and as far east as Central America. It is typically found on or near the bottom in clear water, at a depth of 8–40 m (26–131 ft).
During the day, whitetip reef sharks spend much of their time
resting inside caves. Unlike other requiem sharks, which rely on ram
ventilation and must constantly swim to breathe, this shark can pump
water over its gills and lie still on the bottom. At night, whitetip reef sharks emerge to hunt bony fishes, crustaceans, and octopus
in groups, their elongate bodies allowing them to force their way into
crevices and holes to extract hidden prey. Individuals may stay within a
particular area of the reef for months or years, frequently returning
to the same shelter. This species is viviparous, in which the developing embryos are sustained by a placental connection to their mother. One of the few sharks in which mating
has been observed in the wild, receptive female whitetip reef sharks
are followed by prospective males, which attempt to grasp her pectoral fin and maneuver the two of them into positions suitable for copulation. Females give birth to one to six pups every other year, after a gestation period of 10–13 months.
resting inside caves. Unlike other requiem sharks, which rely on ram
ventilation and must constantly swim to breathe, this shark can pump
water over its gills and lie still on the bottom. At night, whitetip reef sharks emerge to hunt bony fishes, crustaceans, and octopus
in groups, their elongate bodies allowing them to force their way into
crevices and holes to extract hidden prey. Individuals may stay within a
particular area of the reef for months or years, frequently returning
to the same shelter. This species is viviparous, in which the developing embryos are sustained by a placental connection to their mother. One of the few sharks in which mating
has been observed in the wild, receptive female whitetip reef sharks
are followed by prospective males, which attempt to grasp her pectoral fin and maneuver the two of them into positions suitable for copulation. Females give birth to one to six pups every other year, after a gestation period of 10–13 months.
Whitetip reef sharks are rarely aggressive towards humans, though they may investigate swimmers closely. However, spear fishers are at risk of being bitten by one attempting to steal their catch. This species is caught for food, though ciguatera poisoning resulting from its consumption has been reported. The IUCN has assessed the whitetip reef shark as Near Threatened,
noting its numbers are dwindling due to increasing levels of
unregulated fishing activity across its range. The slow reproductive
rate and limited habitat preferences of this species renders its
populations vulnerable to overfishing.
noting its numbers are dwindling due to increasing levels of
unregulated fishing activity across its range. The slow reproductive
rate and limited habitat preferences of this species renders its
populations vulnerable to overfishing.
Oceanic whitetip shark in Red Sea
The whitetip reef shark (Triaenodon obesus) is a species of requiem shark, in the family Carcharhinidae, and the only member of its genus.
A small shark usually not exceeding 1.6 m (5.2 ft) in length, this
species is easily recognizable by its slender body and short but broad
head, as well as tubular skin flaps beside the nostrils, oval eyes with vertical pupils, and white-tipped dorsal and caudal fins. One of the most common sharks found on Indo-Pacific coral reefs, the whitetip reef shark occurs as far west as South Africa and as far east as Central America. It is typically found on or near the bottom in clear water, at a depth of 8–40 m (26–131 ft).
A small shark usually not exceeding 1.6 m (5.2 ft) in length, this
species is easily recognizable by its slender body and short but broad
head, as well as tubular skin flaps beside the nostrils, oval eyes with vertical pupils, and white-tipped dorsal and caudal fins. One of the most common sharks found on Indo-Pacific coral reefs, the whitetip reef shark occurs as far west as South Africa and as far east as Central America. It is typically found on or near the bottom in clear water, at a depth of 8–40 m (26–131 ft).
During the day, whitetip reef sharks spend much of their time
resting inside caves. Unlike other requiem sharks, which rely on ram
ventilation and must constantly swim to breathe, this shark can pump
water over its gills and lie still on the bottom. At night, whitetip reef sharks emerge to hunt bony fishes, crustaceans, and octopus
in groups, their elongate bodies allowing them to force their way into
crevices and holes to extract hidden prey. Individuals may stay within a
particular area of the reef for months or years, frequently returning
to the same shelter. This species is viviparous, in which the developing embryos are sustained by a placental connection to their mother. One of the few sharks in which mating
has been observed in the wild, receptive female whitetip reef sharks
are followed by prospective males, which attempt to grasp her pectoral fin and maneuver the two of them into positions suitable for copulation. Females give birth to one to six pups every other year, after a gestation period of 10–13 months.
resting inside caves. Unlike other requiem sharks, which rely on ram
ventilation and must constantly swim to breathe, this shark can pump
water over its gills and lie still on the bottom. At night, whitetip reef sharks emerge to hunt bony fishes, crustaceans, and octopus
in groups, their elongate bodies allowing them to force their way into
crevices and holes to extract hidden prey. Individuals may stay within a
particular area of the reef for months or years, frequently returning
to the same shelter. This species is viviparous, in which the developing embryos are sustained by a placental connection to their mother. One of the few sharks in which mating
has been observed in the wild, receptive female whitetip reef sharks
are followed by prospective males, which attempt to grasp her pectoral fin and maneuver the two of them into positions suitable for copulation. Females give birth to one to six pups every other year, after a gestation period of 10–13 months.
Whitetip reef sharks are rarely aggressive towards humans, though they may investigate swimmers closely. However, spear fishers are at risk of being bitten by one attempting to steal their catch. This species is caught for food, though ciguatera poisoning resulting from its consumption has been reported. The IUCN has assessed the whitetip reef shark as Near Threatened,
noting its numbers are dwindling due to increasing levels of
unregulated fishing activity across its range. The slow reproductive
rate and limited habitat preferences of this species renders its
populations vulnerable to overfishing.
noting its numbers are dwindling due to increasing levels of
unregulated fishing activity across its range. The slow reproductive
rate and limited habitat preferences of this species renders its
populations vulnerable to overfishing.
فرس النبي
السرعوف أو فرس النبي أو الراهبة أو جمل اليهود (الاسم العلمي: Mantodea) من اليونانية (μάντις = mantis = نبي) + (εἶδος = eidos = شكل). ويسميه اليهود "جمل سليمان" (بالعبرية: גמל שלמה).
مزايا السرعوف
من مزايا السرعوف أنه يتغذى على الحشرات مما يجعله أفضل حارس للمزارع من هجوم الحشرات وخاصة الجراد،والسرعوف يهجم على أي حشرة تتحرك أمامه ينقض على الحشرات بالكلابتين
القويتين ويسرع في التهامها فهو لا يتوقف عن الأكل، ويكون أكثر نشاطاً خلال
فصل الصيف حيث تكثر الحشرات الضارة بالمزارع لذلك يعتبر السرعوف أفضل
وسيلة للتخلص من الحشرات دون أي ضرر على النباتات. ومما يميز هذه الحشرة
أيضاً أنها الحشرة الوحيدة التي تستطيع تحريك رأسها دورة كاملة. بعض أنواع
السرعوف تأكل بعض الطيور والقوارض الصغيرة والسحالي الصغيرة والثعابيين. و
من مميزاته انه رشيق حيث يستطيع مباغته فرائسه ويستطيع تغيير لونه ليتلائم
مع لون البيئة التي يعيش فيها ليتخفي من اعدائه ويوهم فرائسه.
أماكن تواجده
تعتبر حشرة فرس النبي واحدة من أشهر الحشرات في العالم وتتواجد في جميع القارات باستثناء قارة واحدة فقط مثل أنتاركتيكا في القطب الجنوبي المتجمد.أنواعه
يوجدمنه الكثير من الأنواع التي تختلف في الحجم من (2 - 14 سنتيمتر) وكذلك
اللون فمنها (الأخضر، الأصفر، الأبيض الخ) حسب البيئة التي يعيش فيها
لتساعدة في التمويه والانقضاض على الحشرات، ويستعمل يديه الأماميّتين في
القبض على الفريسة حيث تتميز بوجود أشواك ومقابض حادة تساعد على إحكام
القبض. يكون نشيط في فصل الصيف وهو كائن يحب الاختباء في الأشجار وتحت الأشياء القديمة.
أنثى السرعوف
أنثى السرعوف أكبر من الذكر وبعد عملية التكاثرتأكل الأنثى رأس الذكر وهنالك قول أنه في رأس الذكر توجد مواد مغذية. بعد
موسم التزاوج لهذه الحشرة تضع الانثى بيضها والذي يتراوح عدده من 75 الي
300 بيضه في كتل رغوية تتصلب لتكون جراب البيضات، وهي محفظة بيض تشبه الشرنقة،
التي يلاحظ وجودها ملتصقة بالأشجار، وبخاصة عند اختفاء الأوراق منها في
فصل الشتاء حيث لا يمكن الاختباء. أما لون البيض فهو بنيّ فاتح ومخطّط
بخطوط تشبه العروق.
زوج من السرعوف
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محفظة بيض السرعوف
صغار السرعوف تخرج من محفظة البيض
صورة لوجه السرعوف تظهر أجزاء الفم و العينين
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أجنحة السرعوف
عدو السرعوف
العدو اللدود له هو طيور النهار والخفافيش والسحالي.عندما يتعرض السرعوف لهجوم يقف ثم يبسط قدماه الأماميتين حتى يعطي عدوه
انطباعا أنه كبير الحجم فيخاف وينسحب. و من مميزاته انه رشيق حيث يستطيع
مباغته فرائسه ويستطيع تغيير لونه ليتلائم مع لون البيئة التي يعيش فيها
ليتخفي من اعدائه ويوهم فرائسه.
يمر السرعوف في مراحل نموه بعدة انسلاخات فعندما يكبر في الحجم لابد من
تغيير جلده الذي بات ضيقا عليه. و تمر الانثي ب 7 انسلاخات في حياتها بينما
الذكر يمر ب 6 انسلاخات لان عمره اقل من عمر انثاه.
دروس استفادها الصينيون من السرعوف
في القرن التاسع عشر الميلادي, ابتكر أحد الرهبان الصينيون في معبد شاولينأسلوباً قتالياً أسماه "أسلوب فرس النبي" فهذه الحشرة هي من علمته هذا
الأسلوب عندما كان يشاهد المعركة الحاصلة بينها وبين حشرة أخرى كان يشاهد
حينها طريقه الدفاع والهجوم لهذه الحشرة التي قادته ليتخذ منها أسلوباً
قتالياً يعتمد على عدة أمور:
- السرعة
- الصلابه
- المرونه
- الثبات
- الركل
- الضرب
- الإسقاط
- المسك
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