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ASSESSMENT OF FAMILY CICHLIDAE INHABITING LAKE MANZALA, EGYPT

Article

Last updated: 22 Jan 2023

Subjects

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Tags

Fisheries

Abstract

The age and growth of cichlid fishes inhabiting Lake Manzala were studied during the peried from August 2000 to September 2001, based on the length-frequency bF samples collected by the surrounding nets. Analysis of the data using (FiSAT) computer program returned the estimate of the von Bertalanffy's growth curve parameters as: L∞ = 28.88 cm (total length); k = 0.53 year-1 for Oreochromis niloticus; L∞ = 21.53 cm; k = 0.59 yr-1 for aureus; L∞ = 23.63 cm; k = 0.27 yr-1 for Sarotherodon galilaeus; and L∞ = 18.38 cm, K=0.55 year-1 for Tilapia zillii. The respective values of the total mortality coefficient "Z" were found to be 3.38, 2.94, 1.02 and 2.26 yr-1. Moreover, their respective natural mortality coefficients "M" were 1.04, 1.21, 0.71 and 1.21 yr-1. The estimated exploitation rates "E" were 0.69, 0.59, 0.31 and 0.47 in respective for the mentioned species. Their relative yield and relative biomass per recruit showed that the stock of O. niloticus and O. aureus were over the exploited. To obtain the maximum relative yield per recruit; the present level of exploitation rate should be reduced by about 20 % for O. niloticus and 10 % for O. aureus. The stocks of S. galilaeus and T. zillii were under the exploitation level.

DOI

10.21608/ejabf.2006.1903

Keywords

tilapia, Cichidae, Growth, Dynamics, Lake Manzala, Egypt

Authors

First Name

El-Azab

Last Name

El-Bokhty

MiddleName

-

Affiliation

National Institute of Oceanography and Fisheries, Alexandria, Egypt

Email

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City

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Orcid

-

Volume

10

Article Issue

4

Related Issue

398

Issue Date

2006-09-01

Receive Date

2017-03-30

Publish Date

2006-09-01

Page Start

85

Page End

106

Print ISSN

1110-6131

Online ISSN

2536-9814

Link

https://ejabf.journals.ekb.eg/article_1903.html

Detail API

https://ejabf.journals.ekb.eg/service?article_code=1903

Order

6

Type

Original Article

Type Code

103

Publication Type

Journal

Publication Title

Egyptian Journal of Aquatic Biology and Fisheries

Publication Link

https://ejabf.journals.ekb.eg/

MainTitle

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Details

Type

Article

Created At

22 Jan 2023