इलाज़मौबरांकी (शारक और रेज़) (sharks and rays) >
Rajiformes (Skates and rays) >
Rajidae (Skates)
Etymology: Dipturus: Greek, di = two + Greek, pteryx = fin (Ref. 45335).
More on author: Smith.
पर्यावरण: पर्यावरण / जलवायु क्षेत्र / गहराई सीमा / वितरण सीमा
पारिस्थितिकी
समुद्री ड़िमरसल; गहराई सीमा 50 - 457 m (Ref. 5578). Subtropical; 26°S - 36°S, 12°E - 29°E (Ref. 114953)
Southeast Atlantic: known only from Lüderitz, Namibia to Port Alfred, Eastern Cape (South Africa)
आकार / वज़न / आयु
परिपक्व अवधि: Lm ? range ? - ? cm
Max length : 130 cm TL पुल्लिंग / अलिंग; (Ref. 114953)
संक्षिप्त वर्णन
पहचान कुंजी | आकृति विज्ञान | मौरफोमैटरिक्स
A striking two-toned longnose skate, medium brown above and abruptly dark grey below, with a large, conspicuous, dark brown blotch on the upper base of each pectoral fin (Ref. 5578). Snout moderately elongated and bluntly triangular, and tail stout, not conspicuously swollen and about equal to body length; pectoral disc with broadly rounded corners and smooth underside without denticles; thorns at nape and along midline of back and tail to 1st dorsal fin, nape spine enormous in young (Ref. 5578). Hatchlings and juveniles with wide-spaced black spots on upper disc, inconspicuous or lost in adolescents and adults; adults sometimes with numerous small white spots (Ref. 5578). Underside with numerous black pores (Ref. 5578).
Body shape (shape guide): other.
Found on soft bottoms of the outer shelf and upper slope (Ref. 5578). Feeds on bony fish, crabs, shrimp, mysids, mantis shrimp, euphausiids, bivalves and cuttlefish (Ref. 5578). Oviparous (Ref. 50449). Eggs have horn-like projections on the shell (Ref. 205). Males reaches maturity at 88-96 cm TL, females possibly slightly larger off Western than Southern coast of South Africa; hatching size at ca. 19 cm TL (Ref. 114953). Commonly taken by hake trawlers (Ref. 5578). Extremely slippery when caught (Ref. 5578).
जीवन चक्र और संभोग व्यवहार
परिपक्व अवधि | पुनरुत्पत्ति | मछलीऔ का अंडे देना | अंडे | उपजाऊपन | लार्वा
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)
आईयूसीएन रेड लिस्ट स्थिति (Ref. 130435: Version 2025-2 (Global))
मनुष्यों के लिए ख़तरा
Harmless
मानव उपयोग
मात्स्यिकी: कोई रुचि बग़ैर
साधन
विशेष रिपोर्ट
XML डाउनलोड करें
इंटरनेट स्रोत
मॉडल पर आधारित अनुमान
पसंदीदा तापमान (संदर्भ
123201): 9.2 - 16.7, mean 11 °C (based on 41 cells).
जातिवृति विविधता सूचकांक (संदर्भ
82804): PD
50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00380 (0.00255 - 0.00567), b=3.19 (3.07 - 3.31), in cm total length, based on LWR estimates for this species & Genus-body shape (Ref.
93245).
ट्रॉफिक स्तर (संदर्भ
69278): 4.1 ±0.69 se; based on food items.
Generation time: 22.0 ( na - na) years. Estimated as median ln(3)/K based on 2
growth studies.
लौटाव (संदर्भ
120179): निम्न, न्यूनतम जनसंख्या दुगनी होने का समय 4.5 - 14 वर्ष। (Fec assumed to be <100).
मछली पकड़ने की भेद्यता (Ref.
59153): Very high vulnerability (75 of 100).
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