أشلاق (القروش و الشفانين) (sharks and rays) >
Rajiformes (Skates and rays) >
Rajidae (Skates)
Etymology: Dipturus: Greek, di = two + Greek, pteryx = fin (Ref. 45335).
Environment: milieu / climate zone / depth range / distribution range
البيئة
بحري القاع; نطاق العمق 137 - 403 m (Ref. 5578). Subtropical; 20°S - 31°S, 30°E - 38°E (Ref. 114953)
Western Indian Ocean: off central Mozambique to Durban, South Africa.
الحجم / وزن / العمر
Maturity: Lm ? range ? - ? cm
Max length : 66.0 cm TL ذكر/ مختلط الجنس; (Ref. 5578)
وصف مختصر
مفاتيح التعريف | الوصف الخارجي | قياسات المظهر الخارجي
A black-spotted longnose skate with an elongated, acutely triangular snout, and a stout tail- just shorter than body and slightly swollen along the mid-section; disc with rounded corners and smooth underside except for small denticles on edges and tip of snout; small thorns on nape and midback to 1st dorsal fin (Ref. 5578). Medium grey to brownish with numerous small dark spots dorsally; grey with conspicuous black pores ventrally (Ref. 5578).
Found on the bottom of the outer shelf and upper slope (Ref. 5578). Probably caught by trawlers (Ref. 5578).Oviparous (Ref. 50449). Eggs have horn-like projections on the shell (Ref. 205). Males reaches maturity at ca. 57 cm TL, females at ca. 64 cm TL (Ref. 114953)
Life cycle and mating behavior
Maturities | التكاثر | Spawnings | Egg(s) | Fecundities | Larvae
Oviparous, paired eggs are laid. Embryos feed solely on yolk (Ref. 50449). Eggs have horn-like projections on the shell (Ref. 205).
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
أدوات
تقارير خاصة
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مصادر علي الأنترنت
Estimates based on models
Preferred temperature (Ref.
123201): 8.8 - 21.2, mean 14.4 °C (based on 4 cells).
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00282 (0.00133 - 0.00596), b=3.25 (3.08 - 3.42), in cm total length, based on LWR estimates for this Genus-body shape (Ref.
93245).
مستوى غذائي (Ref.
69278): 3.8 ±0.6 se; based on size and trophs of closest relatives
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 (46 of 100).
