ইলাসমোব্রাঙ্কি (হাঙ্গর এবং রে) (sharks and rays) >
Rajiformes (Skates and rays) >
Rajidae (Skates)
Etymology: Rostroraja: Latin, rostrum = beak + Latin, raja, -ae = a sting ray (Ref. 45335).
Environment: milieu / climate zone / depth range / distribution range
বাস্তুসংস্থান
সামুদ্রিক তলদেশ বিহারী; গভীরতার পরিসীমা 1 - 183 m (Ref. 117734), usually 15 - 110 m (Ref. 37039). Subtropical; 14°C - 28°C (Ref. 26938); 30°N - 18°N, 98°W - 80°W
Western Central Atlantic: Florida, USA and the Gulf of Mexico.
Length at first maturity / আকৃতি / ওজন / Age
Maturity: Lm 53.7, range 48 - 56 cm
Max length : 53.0 cm WD পুরুষ/ লিঙ্গ অনিধর্ারিত ; (Ref. 7251); সর্বোচ্চ উলি্ল্লখিত বয়স : 9 বৎসর (Ref. 117734)
Disk diamond-shaped; round dark spot surrounded by pale ring on base of each pectoral fin. (Ref. 26938). No small pale or dark spots on upper surface of disk, but sometimes dark blotches. No scapular spines, 1 middorsal row of spines. Distance from ocellus to eye usually less than or about equal to distance between ocelli. Snout with a clear area on each side (Ref. 7251). Upper surface rich chocolate or coffee brown, translucent on either side fo rostral cartilage. Lower surface plain white (Ref. 6902).
Occur from near shore to 183 m depth at temperatures ranging from 14 to 28° C but it is most common inshore of 91 m at 16-25°C. Young occur in shallow bays. Adults tend to live offshore (Ref. 26938). Adults feed mainly on decapod crustaceans and to a lesser extent on other benthic invertebrates and fishes. Oviparous. Distinct pairing with embrace. Young may tend to follow large objects, such as their mother (Ref. 205). Eggs are oblong capsules with stiff pointed horns at the corners deposited in sandy or muddy flats (Ref. 205). Egg capsules are 6.3 cm long and 3.8 cm wide (Ref. 41359).
Life cycle and mating behavior
Maturities | প্রজনন | Spawnings | Egg(s) | Fecundities | শুককীট
Oviparous, paired eggs are laid. Embryos feed solely on yolk (Ref. 50449). Distinct pairing with embrace. oung may tend to follow large objects, such as their mother (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)
Threat to humans
Harmless
Human uses
মৎস্য: গৌণ বাণিজ্যিক ; স্পশর্ী : occasionally
হাতিয়ার
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ইন্টারনেট সুত্র
Estimates based on models
Preferred temperature (Ref.
123201): 21.2 - 27.5, mean 24.9 °C (based on 230 cells).
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00269 (0.00124 - 0.00582), b=3.26 (3.09 - 3.43), in cm total length, based on LWR estimates for this Genus-body shape (Ref.
93245).
ট্রফিক পর্যায়ে (Ref.
69278): 3.8 ±0.58 se; based on food items.
Generation time: 4.8 ( na - na) years. Estimated as median ln(3)/K based on 2
growth studies.
স্থিতিস্থাপক (Ref.
120179): নিম্ন/ , সর্বনিম্ন প্রজন দ্বিগুনের সময় ৪.৪-১৪ বৎসর (k = 0.29; tmax = 9; tm = 5; Fec assumed to be <100).
Fishing Vulnerability (Ref.
59153): Moderate to high vulnerability (45 of 100).
