Growth, mortality, recruitment and fishery regulation of the Nile Tilapia Oreochromis niloticus (Teleostei: Cichlidae) from Manzala Lake, Egypt

Sahar F. MEHANNA, Mohamed G. DESOUKY, Ahmed F. MAKKY


Population parameters of the Nile tilapia, Oreochromis niloticus were studied based on 1500 specimens (8-31cm TL) collected monthly from the Lake Manzala for one year. Age was determined based on scales’ readings and found to be five years. The length-weight relationship can be expressed as W=0.0143*L3.08. The von Bertalanffy growth equations were Lt=34.51 [1-e-0.38(t+ 0.39)] for growth in length and Wt=776.12 (1-e-0.38(t+0.39)]3.08 for growth in weight. The estimated total, natural and fishing mortality rates were 2.02, 0.82 and 1.20 y-1, respectively. The exploitation rate (E) was 0.59 and size at first capture (Lc) was estimated as 14.4cm TL. The relative yield per recruit reached maximum at an exploitation rate (Emax) of 0.6. Oreochromis niloticus stock may be unsustainable due to intensive fishing pressure to meet demand of growing populations, unless proper action is taken to manage the stocks. 


Population dynamics, Age and growth, Mortality, Management.

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Abd-Alla, A. & Talaat, K.M. 2000. Growth and dynamics of Tilapias in Edku Lake, Egypt. Bulletin of Institute of Oceanography and Fisheries, A.R.E. 26: 183-196.

Allen, K.R. 1938. Some observation on the Biology of the Trout (Salmo trutta) in Windermere. Journal of Animal Ecology 7(2): 333-349.

Bakhoum, S.A. & Abdallah, M. 2002. Study to detect impacts of pollution on Fishery biology of tilapias in Lake Manzalah, Egypt. Journal of King AbdulAziz University for Marine Science 13: 147-160.

Beverton, R.J.H. & Holt, S.J. 1966. Manual of Methods for Fish Stock Assessment. Part 2. Tables of Yield Functions. FAO Fish. Tech. Pap./ FAO Doc. (38) Rev. 1: 67 p.

Binohlan, C. & Pauly, D. 1998. The length-weight table. In: Fishbase 1998: concepts, design and data sources. R. Froese and D. Pauly (Eds). ICLARM, Manila, Philippine: 121-123.

Dan-Kishiya 2013. Length-weight relationship and condition factor of five fish Species from a Tropical water supply reservoir in Abuja, Nigeria. American Journal of Research Communication 1(9): 175-187.

Ecoutin, J.M.; Albaret, J.J. & Trape, S. 2005. Length-weight relationships for fish populations of a relatively undisturbed tropical estuary: The Gambia. Fisheries Research 72: 347-351.

El-Bokhty, E.E. 2006. Assessment of family Cichlidae inhabiting Lake Manzala, Egypt. Egyptian Journal of Aquatic Biology and Fisheries 10(4): 85-106.

El-Bokhty, E.E. & El-Far, A.M. 2014. Some fishery aspects of Nile tilapia, Oreochromis niloticus at Rosetta branch of the Nile River, Egypt. Egyptian Journal of Aquatic Biology and Fisheries 18(3): 41-51.

El-Kasheif, M.A.; Authman, M.M.; Al-Ghamdi, F.A.; Ibrahim, S.A. & El- Far, A.M. 2015. Biological aspects and fisheries management of tilapia fish Oreochromis niloticus (Linnaeus, 1758) in El-Bahr El-Faraouny. Canal, Al- Minufiya Province, Egypt. Journal of Fisheries & Aquatic Sciences 10(6): 405-444.

Elliot, H.A.; Daniel, N.A. & Francis, A. 2015. Determination of Morphometric Relationship and Condition Factors of Four Cichlids from Golinga Reservoir in Northern Region of Ghana. On Line Journal of Biological Sciences 15 (3): 201-206.

Farouk, A. 2009. Some studies on water pollution of Manzala Lake by heavy metals and others and effect of these on stock assessment of fish. M.Sc. Thesis, Faculty of Science, Al-Azhar University.

Ford, E. 1933. An account of the herring investigation conducted at Plymouth during the years from 1924-1933. Journal of Marine Biology Association United Kingdom 19: 305-384.

GAFRD 2016. General Authority for Fish Resources Development, the 2016 Statistics Yearbook. Ministry of Agriculture Publications, Cairo, Egypt.

Gayalino, Jr.; Sparre, F.C.P. & Pauly, D. 1997. The FAO-ICLARM Stock Assessment Tools (FiSAT). FAO Computerized Information Series (Fisheries). No.8. Rome, FAO.

Gulland, J.A. 1971. The Fish Resources of the Ocean. West Byfleet Surrey. Fishing News (Books), Ltd. for FAO. 255 p.

Hassan, A.A. & El-Kasheif, M.A. 2013. Age, growth and mortality of the cichlid fish Oreochromis niloticus (L.) from the River Nile at Beni Suef Governorate, Egypt. Egyptian Journal of Aquatic Biology and Fisheries 17(4): 1-12.

Hile, R. 1936. Age and growth of the Cisco leucichthys artedi (Le Sueur) in the lakes of northeastern Highlands, Wisconsin. Bulletin of the Bureau of Fisheries 48: 209-317.

Hossain, M.Y.; Hossen, M.A.; Pramanik, M.N.U.; Nawer, F. & Islam, M.M. 2016. Biometric indices and size at first sexual maturity of eight Alien fish Species from Bangladesh. Egyptian Journal of Aquatic Research 42(3): 331-339.

Hossain, M.Y.; Paul, A.K.; Hossen, M.A.; Islam, M.A.; Pramanik, M.N.U.; Islam, M.A. & Rahman, M.M. 2016. Length-weight relationships of three Gobiidae species from the Rupsha River in southwestern Bangladesh. Journal of Applied Ichthyology 32(6): 1305-1307.

Hossain, M.Y.; Hossen, M.A.; Ahmed, Z.F.; Hossain, M.A.; Pramanik, M.N.U.; Nawer, F.; Paul, A.K.; Khatun, D.; Haque, N. &Islam, M.A. 2017. Length-weight relationships of 12 indigenous fish species in the floodplain Gajner Beel (NW Bangladesh). Journal of Applied Ichthyology 33(4): 842-845.

ICES 2012. ICES Implementation of Advice for Data-limited Stocks in 2012 in its 2012 Advice. ICES CM 2012/ACOM 68. 42 p.

Ikomi, R.B. & Jessa, H.O. 2003. Studies on aspects of the biology of Tilapia mariae (Boulenger, 1899) (Osteichthyes Cichlidae) in Ethiope River, Niger Delta, Nigeria. African Zoology 38(2): 255-264.

Jones, R. & Van-Zalinge, N.P. 1981. Estimates of mortality rate and population size for shrimp in Kuwait waters. Kuwait Bulletin on Marine Sciences 2: 273-288.

Keivany, Y.; Mortazavi, S. & Farhadian, O. 2018. Age and growth of brond-snout, Chondrostoma regium in Beheshtabad River of Chaharmahal & Bakhtiari Province of Iran (Teleostei: Cyprinidae). Iranian Journal of Ichthyology 5(1): 30-43.

Koutrakis, E. & Tsikliras, A.C. 2003. Length-weight relationships of fishes from three northern Aegean estuarine systems (Greece). Journal of Applied Ichthyology 19: 258-260.

Le Cren, E.D. 1951. The length-weight relationship and seasonal cycle in gonad weight and conditions in perch Perca fluviatilis. Journal of Animal Ecology 20(2): 201-219.

Lee, R.M. 1920. A review of the methods of age and growth determination in fishes by means of scales. Fish Invest. London Series 24(2): 1–32.

Mahmoud, H.H. & Mazrouh, M.M. 2008. Biology and fisheries management of Tilapia species in Rosetta branch of the Nile River, Egypt. Egyptian Journal of Aquatic Research 30: 272-285.

Mahmoud, H.H.; Ezzat, A.A.; Ali, T.E. & El-Samman, A. 2013. Fisheries Management of Cichlid Fishes in Nozha Hydrodrome, Alexandria, Egypt. Egyptian Journal of Aquatic Research 39: 283-289.

Martin, W.R. 1949. The Mechanics of environmental control of body form in fishes. University of Toronto Students for Biology 58: 1-91.

Mehanna, S.F. 2005. Population dynamics and management of the Nile tilapia Oreochromis niloticus at Wadi El-Raiyan Lakes, Egypt. African Journal of Biological Sciences 1: 79-88.

Mehanna, S.F. & Al-Mammry, J. 2012. Length-weight relationship of 19 pelagic and demersal fish species from the sea of Oman. 4th International conference on Fisheries and Aquaculture researches, Cairo, 3-6 October, 2012.

Meyer, D.E. 2002. Technology for successful small-scale tilapia culture (CRSP Research Report 02 - 179). CRSP (Aquaculture Collaborative Research Support Program). [Abstract from original paper published in: D. Meyer (Ed). 6to Simposioo Americano de Aquaculture Proceedings: Tilapia Sessions, 22-24 August 2001. Tegucigalpa, Honduras: 97-106.

Mitu, N.R.; Alam, M.M.; Hussain, M.A.; Hasan, M.R. & Singha, A.C. 2019. Length-weight and length-length relationships, sex ratio and condition factors of the Asian striped dwarf catfish Mystus tengara (Hamilton, 1822) (Siluriformes: Bagridae) in the Ganges River, Northwestern Bangladesh. Iranian Journal of Ichthyology 6(1): 21-30.

Mohammed, M.N.; Midhat, A.E. & Kariman, A.S. 2009. Evaluation and Management of the Fisheries of Tilapia Species in Damietta Branch of the River Nile, Egypt. World Journal of Fish and Marine Sciences 1(3): 169-184.

Moreau, J.; Bambino, C. & Pauly, D. 1986. Indices of overall growth performance of 100 tilapia (Cichlidae) populations. In: J.L. Maclean; L.B. Dizon & L.V. Hosillos (eds.). The First Asian Fisheries Forum. Asian Fisheries Society, Manila, Philippines. pp.201-206.

Pauly, D. 1980. On the interrelationships between natural mortality, growth parameters and mean environmental temperature in 175 fish stocks. Journal du Conseil CIEM 39(3): 175-192.

Pauly, D. 1983. Length-converted catch curves. A powerful tool for fisheries research in the tropics. Part1. ICLARM Fish.

Pauly, D. & Munro, J.L. 1984. Once more on the comparison of growth in fish and invertebrates. ICLARM Fishbyte 2(1): 21 p.

Ricker, W.E. 1975. Handbook of computations and interpretations of biological statistics of fish production. Bulletin of Fisheries Research Board Canada 191: 382 p.

Rosenberg, A.A.; Kleisner, K.; Afflerbach, J. & Anderson S.C. 2018. Applying a new ensemble approach to estimating stock status of marine fisheries around the world. Conservation Letters 11(1): 1-9.

Sadeghi, R. & Esmaeili, H.R. 2018. Length-weight relationships of three gobiid species (Perciformes: Gobiidae) along the Iranian intertidal coast of the Persian Gulf and Makran Sea. Journal of Applied Ichthyology 34: 1233-1234.

Shalloof, K.A. 1991. Biological studies on Tilapia species in the middle region of Lake Manzala. M.Sc. Thesis, Faculty of Science, Mansoura University, Egypt 244 p.

Shalloof, K.A. & El- Far, A.M. 2017. Length-Weight Relationship and Condition Factor of Some Fishes from the River Nile in Egypt with Special Reference to Four Tilapia Species. Egyptian Journal of Aquatic Biology and Fisheries 21(2): 33-46.

Simon, A.M.; Hyppolite, A.; Elie, M.; Philippe, A.L. & Jacques, M. 2015. Population parameters of Oreochromis niloticus (Cichlidae) recently Introduced in Lake Toha (Benin, West Africa). International Journal of Fisheries and Aquatic Studies 2(3): 141-145.

Talaat, K.M.M. 1979. Application of some growth models on tilapia populations in Lake Nasser and some other areas of Egyptian inland waters. MSc Thesis, Faculty of Science, Alexandria University. 164 p.

Tomlison, P.K. & Abramson, N.J. 1961. Fitting a Von Bertalanffy growth curve by least squares. Calif. Dept. Fishery Bulletin 116: 1-69.

von Bertalanffy, L. 1938. A quantitative theory of organic growth (Inquiries on growth Laws. 2). Human Biology 10: 181-213.

Walford, L.A. 1946. A new graphic method on describing the growth of animals. Biology Bulletin 90: 141-147.

Whitney, R.R. & Carlender, K.D. 1956. In temperature of body Scale regression for competing body length of fish. Journal of Wild Management 20: 21-27.


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