Some Reproductive Parameters of Synodontis Schall (Bloch and Schneider, 1801) from the River Nile, Egypt

Mekkawy, Imam A.; Hassan, Arafa

doi:10.3923/jfas.2011.456.471

Cited by 21 publications

(18 citation statements)

References 14 publications

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“…The analysis of reproductive functions is a key factor in determining the dynamics of fish populations (Mekkawy and Hassan, 2011;Ojaveer et al, 2015). The presence of pollutants is one of many environmental factors that can result in a dangerously compromised fish reproduction system.…”

Section: Discussionmentioning

confidence: 99%

Effect of Environmental Pollution on Gonads Histology of the Nile Tilapia, Oreochromis niloticus from Lake Manzala, Egypt

Mansour¹,

El-kady²,

Almaaty³

et al. 2018

Egypt. J. of Aquatic Biolo. and Fish.

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Section: Discussionmentioning

confidence: 99%

Effect of Environmental Pollution on Gonads Histology of the Nile Tilapia, Oreochromis niloticus from Lake Manzala, Egypt

Mansour¹,

El-kady²,

Almaaty³

et al. 2018

Egypt. J. of Aquatic Biolo. and Fish.

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“…The different environmental (i.e., pollution) and climatic conditions in the habitats could explain the discrepancies observed between the findings of different authors. Such variability in Lm 50 may be affected by several physical and biological factors in time and fisheries in addition to the fishing efforts and these may account for the discrepancies observed between the aforementioned findings (Mekkawy and Hassan, 2011;El-Kasheif et al, 2012).…”

Section: ------------------------------------------------------------mentioning

confidence: 98%

Biological Aspects and Fisheries Management of Tilapia Fish Oreochromis niloticus (Linnaeus, 1758) in El-Bahr El-Faraouny Canal, Al-Minufiya Province, Egypt

El-Kasheif¹,

Authman²,

Al-Ghamdi³

et al. 2015

J. of Fisheries and Aquatic Science

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In the present investigation, age, growth, mortality, exploitation, yield and biomass and reproduction of Nile tilapia (Oreochromis niloticus) from El-Bahr El-Faraouny Canal, Al-Minufiya Province, Egypt, were determined. The regression parameter "n" of dependence of total weight upon total length was found to be negative allometric growth. The coefficients of condition were computed. The annual rings on fish scales were used for age determination. The longevity of this species was found to be 6 years. The maximum increase in length was noted during the first year of life and showing a gradual decrease in growth as the fish got older. The O. niloticus population had a sex ratio of 1:1.08 (M:F), which did not deviates (χ 2 = 1.997, p>0.05) from the hypothetical distribution of 1:1. The maturity stages were classified macroscopically into five stages. Higher values of gonadosomatic index (GSI) for males and females occurred nearly throughout the year with peak from May to August indicating prolonged spawning season. There is a selective mortality towards smaller fish sizes. Therefore, for management purposes it is recommended that the local authorities must be set a regulation to control the illegal fishing activity and larger mesh sizes of fishing nets should be used to increase the mean lengths at first capture and their marketable sizes leading to more economic returns and also to conserve the spawning stock part of O. niloticus population. A comparison of the various parameters of O. niloticus in the present study with those of other authors in different localities and times in Egypt revealed year-to-year and geographically differences. These differences were discussed and were found to be attributed to the effect of increased pollution of the canal. Finally, the present study recommended that El-Bahr El-Faraouny Canal must be in protection against pollution.

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“…Several investigators have contributed to this aspect of fishery biology (Khan, 1945, Pillay, 1954Bagenal, 1957, 71, 78;Dass, 1964;Wootton, 1973;Singh et al, 1982;Dobriyal, 1988;Victor et al, (2004); Naeem et al (2005); Jacobson et al (2009); Mekkawy andHassan (2011 and2012);Shinkafi et al (2011). A review of the literature reveals that information on fecundity of salmonids is limited.…”

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confidence: 99%

Study on the fecundity of Salmo trutta fario (Brown trout) in Kashmir

Rasool

Jan

2012

JBLS

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The study has been carried in the year 2004 and describes fecundity, spawning season and sex ratio of brown trout, Salmo trutta fario. A total of 121 brown trout (67 males and 54 females) were captured by angling. Gonad somatic index (GSI) confirmed that spawning lasted from October to December. The left ovary, with some exceptions, was found to be longer and heavier producing more eggs than the right one. The absolute fecundity of sampled population varied from 527 to 2445 and the relative fecundity had a mean value of 2.56. Fecundity was positively co-related with the total fish length (r=0.865), fish weight (r=0.9426) ovary weight (r=0.952) and ovary length (r=0.845).

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Some Reproductive Parameters of Synodontis Schall (Bloch and Schneider, 1801) from the River Nile, Egypt

Cited by 21 publications

References 14 publications

Effect of Environmental Pollution on Gonads Histology of the Nile Tilapia, Oreochromis niloticus from Lake Manzala, Egypt

Effect of Environmental Pollution on Gonads Histology of the Nile Tilapia, Oreochromis niloticus from Lake Manzala, Egypt

Biological Aspects and Fisheries Management of Tilapia Fish Oreochromis niloticus (Linnaeus, 1758) in El-Bahr El-Faraouny Canal, Al-Minufiya Province, Egypt

Study on the fecundity of Salmo trutta fario (Brown trout) in Kashmir

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