American Journal of Innovative Research & Applied Sciences
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| ARTICLES | Am. J. innov. res. appl. sci. Volume 7, Issue 2, Pages 91-XX (August 2018)
American Journal of innovative
Research & Applied Sciences
ISSN 2429-5396 (Online)
OCLC Number: 920041286
| AUGUST VOLUME 7 | N° 2 | 2018 |
*Correspondant author and authors Copyright © 2018:
| Habiba Hamdi 1 | Souad El Amrani 2 | and | Najib Charouki 1 |
1. Université d'Abomey-Calavi (UAC) | Ecole Doctorale Pluridisciplinaire | Laboratoire d'Analyse des Dynamiques Sociales et des Etudes du Développement (LADYD) | Abomey-Calavi | Bénin |
2. Université d'Abomey-Calavi (UAC) | Ecole Doctorale Pluridisciplinaire | LADYD | Abomey-Calavi | Bénin |
This article is made freely available as part of this journal's Open Access: ID | Habiba-ManuscriptRef.2-ajira040818 |
Background: The blue shark Prionace glauca is a pelagic shark, from the Carcharhinidae family, it is one of the pelagic predators placed at the top of the food chain. Unfortunately this species is classified as near threatened "NT" in the IUCN red list. In Morocco, pelagic sharks, including P. glauca, are mainly caught by drifting longlines and secondly by gill net “bonitard”. This fishery is practiced mainly in the southern Moroccan area. Objectives: The growth study of P. glauca is done to know in first, the growth mode of this species and secondly to estimate the growth parameters used in stock assessments. Methods: Since February 2015, biological sampling sessions have been conducted at the wholesale fish market of Casablanca where the catches of P. glauca are transited from several Moroccan ports. They include size and weight measurements and sex determination. Results: The mean sizes of males and females are respectively 184.37 cm and 164.71 cm (TL) indicated that male sharks are larger than females. The juveniles dominate catches during the months of May, June and December. During these periods, it was noted the presence of gravid females, suggesting that the farrowing can be done twice a year in the Moroccan zone. The first gives birth to pups during the winter, which grow for almost six months and appear in the catches during the months of May-June. The second is around the month of May giving birth to pups that grow and appear in catches in the months of December-January. The growth parameters are estimated at L∞ = 392.4 cm (TL), K 0.21 / year and t0 = -0.402 year. This animal grows in size and weight symmetrically and can reach a maximum weight of more than 200 kg at 20 years of age. Conclusions: It was found that the blue shark in Moroccan waters has a wide range of size (50- 340 cm TL).The blue shark has a long life, the reason why this animal must be protected against overfishing.
Keywords: blue shark, linear growth, weight-length, size distribution.
PRELIMINARY STUDY OF BLUE SHARK Prionace glauca GROWTH IN MOROCCAN WATERS
| Habiba Hamdi 1 | Souad El Amrani 2 | and | Najib Charouki 1 |. Am. J. innov. res. appl. sci. 2018; 7(2):118-129.
| PDF FULL TEXT | | XML FILE | | EPUB FILE | | Received | 04 August 2018 | | Accepted | 27 August 2018 | | Published | 28 August 2018 |