أشلاق (القروش و الشفانين) (sharks and rays) >
Rajiformes (Skates and rays) >
Rajidae (Skates)
Etymology: Rajella: Latin, raja, -ae = a sting ray (Raja sp.) (Ref. 45335).
Environment: milieu / climate zone / depth range / distribution range
البيئة
بحري قاعية المعيشة; نطاق العمق 400 - 1640 m (Ref. 106604). Deep-water; 15°N - 34°S
Eastern Atlantic: off southern Rio de Oro in Western Sahara, Namibia, and South Africa. Probably occurs throughout the area along the deeper West African slope.
الحجم / وزن / العمر
Maturity: Lm ? range ? - ? cm
Max length : 82.3 cm TL ذكر/ مختلط الجنس; (Ref. 106604)
وصف مختصر
الوصف الخارجي | قياسات المظهر الخارجي
Moderately long snout, small eyes, and a flat disc; tail about as long as body; moderately large, inconspicuous light thorns dorsally and a few on snout; mid-dorsal line of thorns reduced in adolescents and adults (Ref. 5578). Whitish grey to dark grey dorsally, white ventrally with dark rear margins and dark patches on underside of tail (Ref. 5578).
Found in deeper slope waters (Ref. 4426). Feed on cephalopods, mysids and small bony fishes (Ref. 5578). Oviparous (Ref. 50449). Eggs have horn-like projections on the shell (Ref. 205).
Life cycle and mating behavior
النضج | التكاثر | وضع البيض | بيض | الخصوبة | Larvae
Oviparous, paired eggs are laid. Embryos feed solely on yolk (Ref. 50449).
McEachran, J.D. and K.A. Dunn, 1998. Phylogenetic analysis of skates, a morphologically conservative clade of elasmobranchs (Chondrichthyes: Rajidae). Copeia 1998(2):271-290. (Ref. 27314)
IUCN Red List Status (Ref. 130435)
استخدامات بشرية
مصائد: غير ذات اهمية
مزيد من المعلومات
مراجعالأستزراع المائيملف الأستزراع المائيسلالاتجينيElectrophoresesالتوريثالأمراضمعالجةNutrientsMass conversion
أدوات
تقارير خاصة
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مصادر علي الأنترنت
Estimates based on models
Preferred temperature (Ref.
123201): 3.3 - 6.6, mean 4.3 °C (based on 24 cells).
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00288 (0.00177 - 0.00470), b=3.29 (3.16 - 3.42), in cm total length, based on LWR estimates for this species & (Sub)family-body (Ref.
93245).
مستوى غذائي (Ref.
69278): 4.0 ±0.53 se; based on food items.
المرونه (Ref.
120179): منخفض, الحد الزمني الأدني لتضاعف عدد أفراد المجتمع 4.5-14 سنة (Fec assumed to be <100).
Fishing Vulnerability (Ref.
59153): Moderate to high vulnerability (53 of 100).
