scholarly journals Population biology of Nile tilapia, Oreochromis niloticus in Lake Naivasha, Kenya

2020 ◽  
Author(s):  
Edna Waithaka ◽  
Edwine Yongo ◽  
Nicholas Otieno Outa
Keyword(s):  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Population Biology ◽  
Fishery Management ◽  
Total Mortality ◽  
Sustainable Yield ◽  
Lake Naivasha ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Fish Samples ◽  
The Mean

The Nile tilapia, Oreochromis niloticus was introduced in Lake Naivasha to provide exploitable fisheries. It is one of the commercially important fish providing livelihoods to communities around the lake. However, its stocks in the lake have been declining due to intense fishing, ecological changes and effects of other exotic species. This study investigated on its population and biological parameters. Fish samples (1021) were caught monthly from January to December 2017 using gillnets of mesh-sizes 2-5 inches. A total of 1021 O. niloticus caught had overall sex ratio of 2.21:1.0 (male: female). Length of fish ranged from 9.0 to 40.0 cm TL and weighed between 20 and 1220 g. Length at first maturity (Lm50) was estimated at 28.0 cm TL for all sexes. The mean length and weight for all fish was 22.6 cm and 272.6 g. The slope b of length-weight relationship was 2.86 for all fish. The mean condition factor was 0.99, 1.04 and 1.01 for male, female and all fish, respectively. The asymptotic length (L∞) was 42 cm, growth coefficient (K) 0.21 year−1 and growth performance index (Ф) 2.57. The natural (M), fishing (F) and total mortality (Z) coefficients were estimated at 0.55, 0.26 and 0.80 year−1, respectively. Length at first capture (Lc50) was calculated at 19.38 cm. The optimum sustainable yield (E0.5), maximum sustainable yield (Emax) and maximum economic yield (E0.1) indices were 0.23, 0.35 and 0.26, respectively. This study has provided some insights into biology of O. niloticus and stock assessment relevant information to the fishery management.

scholarly journals Population Biology of Nile tilapia (Oreochromis niloticus ) in Lake Naivasha, Kenya

2020 ◽  
Vol 25 (2) ◽  
pp. 244-249
Author(s):  
Edna Waithaka ◽  
Edwine Yongo ◽  
Nicholas Outa ◽  
Eunice Mutethya
Keyword(s):  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Population Biology ◽  
Lake Naivasha ◽  
Nile Tilapia Oreochromis Niloticus

scholarly journals DINAMIKA POPULASI IKAN NILA (Oreochromis niloticus Linnaeus, 1758) DI DANAU PANIAI, PAPUA

2018 ◽  
Vol 23 (3) ◽  
pp. 193
Author(s):  
Samuel Samuel ◽  
Yoga Candra Ditya ◽  
Vipen Adiansyah
Keyword(s):  
Fish Species ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Lake Management ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Average Maximum ◽  
Fish Samples ◽  
Information Research ◽  
Endemic Fish ◽  
Average Size

Introduksi ikan nila atau “serapia” (Oreochromis niloticus) di Danau Paniai bertujuan untuk meningkatkan diversitas hasil tangkapan dan mengurangi tekanan eksploitasi terhadap jenis ikan endemik. Pertumbuhan dan produksi ikan nila yang cepat tanpa diiringi upaya pengelolaan akan mengancam keberlanjutan ikan endemik di danau. Upaya pengelolaan sumberdaya ikan di suatu perairan membutuhkan informasi dinamika populasi. Penelitian dinamika dan pengelolaan populasi ikan nila dilakukan pada bulan Februari sampai Oktober 2016. Contoh ikan dikumpulkan dari hasil tangkapan nelayan dengan menggunakan jaring insang dengan berbagai ukuran mata jaring dan dari 4 (empat) enumerator pada tujuh stasiun pengamatan. Hasil penelitian menunjukkan populasi ikan nila di Danau Paniai didominasi ukuran panjang individu antara 15-25 cm sebanyak 67,24%. Pola pertumbuhan ikan jantan dan betina adalah isometrik, panjang maksimum rata-rata (L) adalah 37,28 cm dan koefisien pertumbuhan (K) adalah 0,50 per tahun. Mortalitas alami (M) dan mortalitas penangkapan (F) masing-masing sebesar 0,99 dan 0,54 per tahun. Tingkat eksploitasi (E) diperoleh nilai 0,35 lebih kecil dari nilai optimum (E=0,5). Ukuran rata-rata ikan nila tertangkap (Lc) adalah 20,55 cm lebih besar dari ukuran pertama matang gonad (Lm) sebesar 14,73 cm. Nilai Lc>Lm mengindikasikan sebagian besar populasi ikan nila di Danau Paniai sempat melakukan pemijahan sehingga pemanfaatan lebih atau sama dengan nilai optimum diharapkan dapat meningkatkan pemanfataan ikan nila di Danau Paniai. Introduction of nile tilapia (Oreochromis niloticus) in Lake Paniai known as “serapia” is aimed for improving the diversity of catches and reducing the exploitation pressure on the endemic fish species. The rapid growth, reproduction and production of nile tilapia without its management efforts is a new threat to the sustainability of the existence and utilization of endemic fish species in the lake. Management efforts of fish resources require population dynamics information. Research on the dynamics and management of nile tilapia populations was conducted from February to October 2016. Fish samples were collected from fishermen catches using nets with various mesh sizes and from four enumerators at seven observation stations. The results showed that the population of nile tilapia in Lake Paniai was dominated by individual length between 15-25 cm with frequency of 67,24%. The growth pattern of male and female fish were isometric, the average maximum length (L) was 37.28 cm and the growth coefficient (K) was 0.50 per year. Natural mortality (M) and fishing mortality (F) were 0.99 and 0.54 per year respectively. Exploitation rate (E) of 0.35 was smaller than the optimum value (E=0.5). The average size of nile tilapia captured (Lc) was 20.55 cm larger than the first size of gonad maturity (Lm) of 14.73 cm. The Lc value was higher than that the Lm value(Lc>Lm) indicating that most of nile tilapia population in Lake Paniai has spawned so that increasing the more or equal to the optimum value was expected to improve the of nile tilapia fish in Lake Paniai.

scholarly journals Trichodina magna Van As and Basson, 1989 (Ciliophora: Peritrichia) from cultured Nile tilapia in the state of Santa Catarina, Brazil

2008 ◽  
Vol 68 (1) ◽  
pp. 169-172 ◽  
Author(s):  
ML. Martins ◽  
L. Ghiraldelli
Keyword(s):  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Original Description ◽  
The State ◽  
The Body ◽  
Fish Ponds ◽  
Santa Catarina ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Mean Diameter ◽  
The Mean

Specimens of Trichodina magna Van As and Bassson, 1989 (Ciliophora: Peritrichia) from the Nile tilapia Oreochromis niloticus collected from October 2004 to June 2005 in fish ponds situated in three regions of Santa Catarina State, Brazil are described here. Wet smears of skin and gills were prepared in the field, air dried, impregnated with Klein’s dry silver method and Giemsa’s solution. From a total of 146 examined fish, 36 were parasitized on the skin, 14 in the gills and 33 on the skin and gills, simultaneously. The mean diameter of the body of the specimens of T. magna was 84.3 ± 12.6 µm, adhesive disc 60.7 ± 10.0 µm, denticulate ring, 38.3 ± 7.4 µm, consisting of 26 (23 to 29) denticles. The only distinguishable difference from the original description was the fact that the ray of the denticle is anteriorly directed and does not extend over the y + 1 axis.

scholarly journals Association between Heavy Metals and Selected Reproductive Parameters in the Nile Tilapia, Oreochromis niloticus, along River Ruiru, Kiambu County, Kenya

2020 ◽  
pp. 31-44
Author(s):  
Ong’eta M. K Wamboka ◽  
Syprine A. Otieno ◽  
Jemimah A. Simbauni
Keyword(s):  
Heavy Metals ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Tropical Fish ◽  
Enzyme Linked Immunosorbent Assay ◽  
Reproductive Parameters ◽  
Reproductive Process ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Significant Difference ◽  
Fish Samples

The Nile tilapia, Oreochromis niloticus, is a tropical fish species of commercial importance in both aquaculture and in the wild. It plays a great role in human nutrition and food security. River Ruiru is one of the rivers faced with pollution from nearby industries. It is inhabited by various species of fish such as tilapia and common carp, which, may be harvested by surrounding communities for food. High levels of heavy metals disrupt normal reproductive process in fish. Besides, it has been reported that edible fish contaminated with heavy metals has deleterious effects on the health of humans and other animals that consume them. There is no documented information on the association between heavy metals and the reproductive biology of Oreochromis niloticus in River Ruiru. This study was aimed at assessing the level of heavy metals in fish ovaries and their association with selected reproductive parameters in the reproductive cycle of O. niloticus. Fish samples were collected monthly, for 8 months, from the downstream and upstream sections. Gonadosomatic index (GSI), serum 17β-estradiol (E2) levels and levels of heavy metals lead, cadmium, copper, iron and zinc in ovaries were determined. The levels of the heavy metals were measured using Atomic Absorption Spectrophotometer. The level of E2 was analyzed using Enzyme-Linked Immunosorbent Assay. There was no significant difference in the GSI between the upstream and the downstream sites (t=0.82, p=0.416). Similarly, there was no significant difference in the levels of E2 between the downstream and the upstream sampling sections. In the downstream, the levels of lead and iron in fish ovaries were significantly higher compared to the upstream (lead: t = 3.36, p = 0.002; iron: t = 4.920, p=0.001). The results showed that levels of heavy metals did not associate with the selected reproductive parameters in the Nile tilapia, along River Ruiru. Levels of lead and cadmium were above allowable concentrations for fish consumption when compared to WHO levels. The study recommends that the Ministry of Environment and Natural Resources should put measures in place to stop discharging raw effluents into River Ruiru.

scholarly journals Prevalence of parasitic infections on cultured Nile tilapia, Oreochromis niloticus (Linnaeus, 1758) In Bong County, Liberia

2021 ◽  
Vol 62 (1) ◽  
pp. 13-25
Author(s):  
S. Addo ◽  
S. Mullah ◽  
P. K. Ofori-Danson ◽  
S. K. K. Amponsah ◽  
J. O. Nyarko
Keyword(s):  
Water Quality ◽  
Relative Abundance ◽  
Oreochromis Niloticus ◽  
Prevalence Rate ◽  
Nile Tilapia ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Parasitic Infections ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Fish Samples

This study investigated the prevalence rate, relative abundance and mean intensity of par­asites infecting cultured Nile tilapia Oreochromis niloticus L. in three fish farms, Gbarnga, Warta and CARI in Bong County, Liberia. Organs from thirty fish samples were exam­ined from September 2016 to February 2017, along with water quality parameters. Results showed the occurrence of seven parasites including protozoans, monogeneans, digeneans, cestodes, hirudineans, nematodes and crustaceans which were organ specific in terms of infection. The prevalence of the parasites varied seasonally, with the highest numbers oc­curring in November-January. The low prevalence rate, relative abundance and mean in­tensity of the parasites showed no threat to fish farmers in Liberia. All the water quality parameters were at desirable levels for the culture of the fish except nitrite, which was beyond the threshold for sustainable fish culture. It is therefore concluded that although parasitic infections in the three farms in the Bong County were low, best farm management practices are essential.

scholarly journals Fluktuasi asimetri ikan nila (Oreochromis niloticus) di Pusat Pelatihan Mandiri Kelautan dan Perikanan (P2MKP) Dunia Air, Banyuwangi

2017 ◽  
Vol 2 (1) ◽  
Author(s):  
Darmawan Setia Budi ◽  
Lailatul Lutfiyah
Keyword(s):  
Lateral Line ◽  
Fluctuating Asymmetry ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Quantitative Information ◽  
Meristic Characters ◽  
Pectoral Fins ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Fish Samples ◽  
The Stability

Fluctuating asymmetry of the bilateral meristic characteristic is one of the simple methods that can be used to determine the stability of an individual fish development. This study aims to provide quantitative information about the level of asymmetry of Nile tilapia (Oreochromis niloticus) in Dunia Air Independent Training Center Marine and Fisheries, Banyuwangi through bilateral meristic characteristic observation.  A total of 120 fish samples (5-7 cm) were measured in this study. Four bilateral meristic characters were calculated i.e. the number of soft pectoral fins, number of soft ventral fins, number of scales on the lateral line up and down. The results show that the highest value of the fluctuating asymmetry of magnitude (FAm) and fluctuating asymmetry of number (FAn) was obtained at the number of scales on the lateral line up those are 2.14 and 0.78, respectively. Meanwhile, the lowest FAm and FAn values obtained from the soft ventral fins which were 1.69 and 0.78, respectively. The sum of the total value of fluctuating asymmetry of each bilateral meristic characteristic was observed. The overall FAm value was 7.83 and the overall FAn value was 2.99.Keywords: fluctuating asymmetry, Nile tilapia, PMKP Dunia Air 

scholarly journals A Comparative Study on the Growth, Feed Conversion and Production of Fry of Improved and Non-improved Strains of the Nile Tilapia Oreochromis niloticus

2007 ◽  
Vol 19 (4) ◽  
Author(s):  
M.T. RIDHA
Keyword(s):  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Survival Rates ◽  
Feed Conversion ◽  
Daily Growth ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Fish Weight ◽  
The Gift ◽  
Genetically Improved ◽  
The Mean

Two experiments were conducted consecutively to evaluate and compare the mean weight (MWT), daily growth rate (DGR), feed conversion ratio (FCR), survival and production rate (PR) in the non-improved strain (NS) of the Nile tilapia, Oreochromis niloticus (Cichlidae) with those in the Genetically Improved Farmed Tilapia (GIFT) strain and the FaST selected tilapia (FaST), from the swim-up fry stage to fish weight of 1.0 g (Experiment 1) and from fish weight of 1.0 to 20 g (Experiment 2). In both experiments, results showed the GIFT and FaST strains to have significantly higher MWT, faster DGR, lower FCR and higher PR than those of the NS. Unlike in Experiment 1, survival rates did not differ significantly among the three strains. In Experiment 1, the improvements in the FaST for the MWT, DGR and PR over those for the NS were 77.9, 72.9 and 33.6%, respectively. In Experiment 2, the improvements for the same parameters were 58.7, 57.8 and 54.5%, respectively. These results indicate the advantage and potential of culturing the FaST or the GIFT strain in Kuwait for improving the production of fresh tilapia, reducing the production cost and increasing the profitability of tilapia farms.

scholarly journals Morfometrik lima species ikan yang dominan tertangkap di Danau Aneuk Laot, Kota Sabang

DEPIK ◽  
2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Auliyanisa Khayra ◽  
Zainal A. Muchlisin ◽  
Muhammad A. Sarong
Keyword(s):  
Fish Species ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Survey Method ◽  
Fish Sample ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Fish Samples ◽  
Channa Striata ◽  
Morphological Relationship

Abstract. The objective of the present study was to analyze the morphometric variationsof five predominant fish species caught in Lake Aneuk Laot, Sabang City,Weh Island.The study was conducted in December 2015 to January 2016. The survey method was used in this study. The fish target were Nile tilapia (Oreochromis niloticus), tilapia (O. mossambicus), snakeskin gourami (Trichopodus pectoralis), giant gourami (Osphronemus goramy) and snakehead (Channa striata). The fish samples were catched using gillnets. The fish sample were analyzed for traditional and truss network morphometrics. The results showed that there is closed morphological relationship between Nile tilapia and tilapia, and between snakeskin gourami and giant gourami, while the snakehead fish was discriminated apart from the two previous groups.Keywords: Morphometric Nile tilapia, tilapia, snakeskin gourami, giant gourami, snakehead fish, Weh Island Abstrak. Penelitian ini bertujuan untuk menganalisis variasi morfologi ikan hasil tangkapan dominan di Danau Aneuk Laot Kota Sabang dengan menggunakan teknik traditional dan truss morphometric. Penelitian dilakukan pada Desember 2015 sampai Januari 2016. Ikan sampel terdiri dari ikan nila (Oreochromis niloticus), ikan mujair (O. mossambicus), ikan sepat siam (Trichopodus pectoralis), ikan gurami (Osphronemus gorami) dan ikan gabus (Channa striata). Ikan sampel diperoleh dengan menggunakan alat tangkap jaring. Sebanyak 12 karakter traditional morphometric and 14 karakter truss dianalisis dalam penelitian ini.  Hasil penelitian menunjukkan terdapat tiga kelompok ikan, kelompok pertama ikan nila dan ikan mujair, kedua ikan ini kemiripan yang tinggi; kelompok kedua adalah ikan sepat siam dan ikan gurami, kelompok ketiga adalah ikan gabus yang memiliki kemiripan yang jauh dengan kedua kelompok ikan sebelumnya.Kata kunci: Morfometrik, Nila, mujair, sepat siam, gurami, gabus, Pulau Weh

scholarly journals Morphological variability of the 11th generation strain of nile tilapia, (Oreochromis niloticus) and traditional genetically improved farmed tilapia

2012 ◽  
Vol 9 (2) ◽  
pp. 345-349 ◽  
Author(s):  
KM Shahriar Nazrul ◽  
AA Mamun ◽  
BS Sarker ◽  
US Tonny
Keyword(s):  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Linear Growth ◽  
Morphological Variability ◽  
Meristic Characters ◽  
Mean Values ◽  
Total Length ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Significant Difference ◽  
The Mean

To investigate the morphological variations 12 morphometric and 11meristic characters were studied for 100 individuals of the same age of traditional strain GIFT (5th generation) and recently developed 11th generation strain    (GIFU) of Nile tilapia, Oreochromis niloticus. No significant difference was found between total length and other body measurements at 5% level. However, GIFU showed faster linear growth on body depth, maximum body circumference and minimum body circumference where GIFT showed faster linear growth on standard length and head length. On meristic characters, notable variations were observed in case of scale above and below the lateral line, where GIFU individuals showed greater number of scales in both cases. The total length and body weight relationship of both the strains were found to be straight line in logarithmic scales. The mean values of condition factor (K) have been found to be 1.671 for GIFT and 1.711 for GIFU and the mean values of relative condition facto (Kn) were 1.001 and 1.002 for GIFT and GIFU respectively. Findings of the present study suggested the variability of strain GIFU and GIFT in some important parameters.   DOI: http://dx.doi.org/10.3329/jbau.v9i2.11050   J. Bangladesh Agril. Univ. 9(2): 345–349, 2011

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