أشلاق (القروش و الشفانين) (sharks and rays)
(Shovelnose rays) > Pristidae
Etymology: Pristis: Greek, pristis = saw (Ref. 45335).
Environment: milieu / climate zone / depth range / distribution range
بحري; المياه العذبة; مياه مخلوطة القاع; مهاجرة بين الياه الملحه و الحلوة لكن ليس للتزاوج (Ref. 51243); نطاق العمق 10 - 88 m (Ref. 114953). Subtropical; 16°C - 30°C; 44°N - 37°S, 180°W - 180°E
Circumglobal (Ref. 4429). Western Atlantic: North Carolina (USA), Bermuda and northern Gulf of Mexico (Ref. 7251) to Argentina (Ref. 58839); Caribbean Sea: rare in Bermuda (Ref. 26938); eastern Atlantic: Gibraltar to Namibia; possibly in the Mediterranean Sea (Ref. 9859; though not reported since 1902, Ref. 116564); Indo-West Pacific: Red Sea and East Africa to the Philippines (Ref. 9859). Possibly occurring in the eastern Pacific (Ref. 9859).
الحجم / وزن / العمر
Maturity: Lm ?  range ? - ? cm
Max length : 760 cm TL ذكر/ مختلط الجنس; (Ref. 6871); common length : 550 cm TL ذكر/ مختلط الجنس; (Ref. 6871); أعلا وزن تم نشرة: 350.0 kg (Ref. 3164)
Diagnosis: Pristis pectinata is easily separable from Pristis perotteti by the following characters: its first dorsal fin originates about over the origin of its pelvic fins vs. considerably in front of origin of pelvic fins in P. perotteti; its caudal fin is much shorter, but broader relative to the length of the fin, with lower lobe only faintly indicated; its rostral teeth are numerous, 23 or more on each side vs. not more than 20 in P. perotteti; its saw is relatively somewhat shorter; its second dorsal fin has the posterior margin much less deeply concave; and its pectoral fins are smaller (Ref. 6902, 81624). Pristis pectinata agrees with Pristis pristis in the shape of its caudal fin and in the position of the first dorsal fin relative to the pelvic fins, but it can be separated from P. pristis by its more numerous rostral teeth, 23 or more on each side vs. less than 20 (Ref. 6902, 81624).
Inshore and intertidal species, but may cross deep water to reach offshore islands; also ascends rivers and can tolerate fresh water (Ref. 9859). Commonly seen in bays, lagoons, estuaries, and river mouths. Also found in rivers and lakes (Ref. 12951). Feeds on fishes and shellfishes (Ref. 58784). Ovoviviparous (Ref. 50449). Gravid females reportedly carry as many as 20 embryos, which require a year of gestation (Ref. 27549). Uses its saw to stir the bottom when feeding on bottom invertebrates and to kill pelagic fishes (Ref. 9859). Utilized as a food fish; oil is used to make medicine, soap and in leather tanning (Ref. 6871). Adults stuffed for decoration (Ref. 6871). Reported to be aggressive towards sharks when kept in tanks (Ref. 12951). This species is currently protected in several areas as populations are under severe threat (Ref. 81624).
Life cycle and mating behavior
النضج | التكاثر | وضع البيض | بيض | الخصوبة | Larvae
Ovoviviparous, with gravid females containing about 15-20 embryos (Ref. 3163). Embryos feed solely on yolk (Ref. 50449). Gives birth in shallow bays and estuaries (Ref. 12951). Size at birth 61 cm (Ref. 12951).
Last, P.R. and J.D. Stevens, 1994. Sharks and rays of Australia. CSIRO, Australia. 513 p. (Ref. 6871)
IUCN Red List Status (Ref. 125652)
Traumatogenic (Ref. 6871)
مصائد: غير مهمة تجارياً; لعبة سمكه: نعم
مزيد من المعلومات
مراجعالأستزراع المائيملف الأستزراع المائيسلالاتجينيتواتر الأليلالتوريثالأمراضمعالجةNutrientsMass conversion
مصادر علي الأنترنت
Estimates based on models
Preferred temperature (Ref. 123201
): 22.9 - 28, mean 27.1 °C (based on 776 cells).
Phylogenetic diversity index (Ref. 82804
= 0.5234 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00407 (0.00161 - 0.01032), b=3.02 (2.80 - 3.24), in cm total length, based on LWR estimates for this species & (Sub)family-body (Ref. 93245
مستوى غذائي (Ref. 69278
): 4.5 ±0.80 se; based on food items.
Generation time: 32.3 ( na - na) years. Estimated as median ln(3)/K based on 2 growth studies.
المرونه (Ref. 120179
): منخفض, الحد الزمني الأدني لتضاعف عدد أفراد المجتمع 4.5-14 سنة (Fec=15).
Fishing Vulnerability (Ref. 59153
): Very high vulnerability (84 of 100).