Fisheries and biology of spinner shark Carcharhinus brevipinna in Ras-Lanuf shores, Libya-spring and summer 2019

العناوين الأخرى

مصائد وبيولوجية كلب بحر بوريشة Carcharhinus brevipinna في ساحل راس لانوف ليبيا ربيع وصيف 2019

المؤلفون المشاركون

Bu Zayd, Isam Mahmud Khamis
Birfad, Muhammad Ayyad

المصدر

مجلة جامعة مصراتة للعلوم الزراعية

الناشر

جامعة مصراتة كلية الزراعة

تاريخ النشر

2021-12-31

دولة النشر

ليبيا

عدد الصفحات

22

التخصصات الرئيسية

العلوم البحرية

الملخص الإنجليزي

Between March and August 2019, about 52 specimens of Carcharhinus brevipinna were collected from Ras-lanuf shores, Libya.

In a size range (60.3-270.3 cm) and weights (1551.11-39510.22 gm), to study their biology: In length-weight relationship was isometric (B=2.5934); values of condition factors (Kf and Kc) plummeted by increasing size, from 0.42 and 0.28 in 77.6 cm size, to Kf = 0.17 in 145.8 cm and Kc = 0.13 in 178.6 cm.

The presence of the middle group (178.6 cm) peaked by the quarter (26.9%), whereas the largest group had the lowest attendance by 7.6%.

The variance of the H.S.I.

started by 20.8% to drop in the middle (15.2%) raising to 25.7% in the largest specimens.

G.S.I.

averages of males and females indicated gradually from 1.20 and 1.00 in the small sizes, till 4.31 and 4.82, respectively.

The sex ratio of males and females approached by 1.33: 1.00 respectively.

Their stomachs contained pelagic teleosts (44.6%) then mollusks by 20.3 %, with the benthic fishes, cephalopods and juvenile cartilaginous fishes constituted by 17.6, 9.4 and 8.1% respectively.

Pelagics peaked in 113.9 cm by 65.0% and dropped (30.4%) in 229.1 cm; in 77.6 cm, the bony benthics and cartilaginous fishes recorded 52.2 and 14.6% respectively, with 16.7 of mollusks, compare to 29.8% in 178.6 cm, cephalopods peaked to 20.0% in 145.8cm.

This study is beneficial for studies the population dynamics of this species and others in the Libyan coast, to manage the fish stocks-assessment and to protect the immature individuals in coasts and nursery grounds from overfishing.

نوع البيانات

أوراق مؤتمرات

رقم السجل

BIM-1456977

• APA
• MLA
• AMA