Niloticus Fish Research Articles

Trials for the control of trichodinosis and gyrodactylosis in hatchery reared Oreochromis niloticus fries by using garlic

The present work was designed to study the prevalence of trichodinosis and gyrodactylosis in Oreochromis niloticus fries, and to test the therapeutic efficacy and preventive efficacy of garlic oil and crushed garlic cloves. Trichodinosis and gyrodactylosis are ectoparasitic diseases that affect most warm freshwater fish, especially fries and fingerlings. In a private O. niloticus fish hatchery, the prevalence of trichodinosis in 5-, 15- and 30-day-old-fries was 37%, 23% and 40.5%, respectively. The highest infection intensity was detected in 30-day-old-fries. The gyrodactylosis was reported only in combination with trichodinosis. In addition, we found that its prevalence in 5-, 15- and 30-day-old-fries was 17%, 19.5% and 29%, respectively. Mortality rate of fry in the first month of life was 53% as a result of injury to these two types of parasites. The garlic oil and crushed garlic cloves were tested in both in vitro and earthen ponds of the hatchery. Using 2-, 2.5- and 3-ppt (parts per thousand) garlic oil for 4h in vitro water bath treatment resulted in 100% recovery, while 1 and 1.5ppt garlic oil, respectively, needed 24 and 16h to treat the infected fries. The treatment by 3ppt garlic oil as a water bath for 1h treated the two diseases in 55% in 7 days from application in the hatchery earthen pond. In the mean time, 300mgL−1 crushed garlic cloves as an indefinite bath in the hatchery earthen pond eliminated 68% of the diseases. The same protocol for preventing the two diseases resulted in obtaining 65% and 75% of parasite free fries, for garlic oil and crushed garlic cloves, respectively, compared to 53% of the control fries.

Effect of turbidity on the ultraviolet disinfection performance in recirculating aquaculture systems with low water exchange

This research was carried out to study the effect of turbidity on the effectiveness of ultraviolet light (UVC) for removing heterotrophic bacteria (HB) from two commercial recirculating aquaculture systems (RAS). We developed a simple and straightforward UV disinfection model based on water turbidity to predict the cost-effectiveness of disinfection. The UVC from RAS1 (12.8 m3, 80 L min−1, indoor system) was tested at 9.2, 9.9, 16.3, 17.2, 23.1 and 28.2 nephelometric turbidity units (NTU) after 24 h of exposure. The RAS2 (140 m3, 1140 L min−1, outdoor system) was tested at 8.0, 9.2, 11.0, 12.1, 16.0, 24.2, 27.0, 31.3 and 31.7 NTU after 72 h. An increase in turbidity in the water was achieved by rearing Oreochromis niloticus fish. The RAS1 achieved a maximum UV efficiency (89.8%≈1 Log) at 9.2 NTU after 24 h and RAS2 at 8.0 NTU (86.4%≈0.9 Log) after 72 h of exposure. For RAS1, the UVC removed 90% of HB in 24 h when the turbidity was <9.9 NTU. For RAS2, without restrictions on particle size and relatively high phytoplankton abundance, the UV was unlikely to be a cost-effective way of removing HB at turbidity above 11.0 NTU.

Autohydrolysed Tilapia nilotica Fish Viscera as a Peptone Source in Bacteriocin Production.

Fish processing generates large amounts of solid and liquid wastes. Many different by-products have been produced from fish processing wastes. Studies on solubilization of Bolti fish (Tilapia nilotica) viscera by endogenous enzymes at different pHs are described. Hydrolysis reactions were conducted with freshly thawed viscera utilizing an initial temperature gradient and terminated at various time points by heat inactivation of the enzymes. Various peptones obtained from hydrolysed visceral homogenates of Bolti fish residues showed their suitability for promoting the growth of lactic acid bacteria (mainly Lactobacillus sake Lb 706), microorganisms with particularly complex nutritional requirements especially peptidic sources. The assay of several treatments with L. sakei Lb 706, producer of the bacteriocin sakacin A, demonstrated that optimum conditions for biomass and bacteriocin production only imply a brief autohydrolysis at room temperature. The results showed that the Bolti fish hydrolysates gave remarkable results to those found in costly commercial media, specifically recommended for culturing and large-scale production of lactic acid bacteria.

Ibuprofen Genotoxicity in Aquatic Environment: An Experimental Model Using Oreochromis niloticus

Medicines and their metabolites have been found as water contaminants at very low concentrations; moreover, there is no extensive toxicological data to determine the risks associated with their occurrence in water resources. The ibuprofen genotoxicity potential to the Oreochromis niloticus fish (Tilapia), due to nanograms per liter exposure, was evaluated using the micronucleus test. Acute (48 h) and sub-chronic assays (10 days) were carried out at 300 ng/L ibuprofen aquatic concentration comparing with the negative control group (without treatment), with eight animals per group. The results were assessed from the average of triplicate analyses. The micronucleus frequency in peripheral blood of fish was determined using a sample size of 3,000 erythrocytes per animal. Significance was defined using t test (p ≤ 0.05). The bioassay results showed a statistically significant increase in the frequency of micronuclei for both exposure times in comparison to the negative control. The micronucleus frequency observed for the sub-chronic tests was higher than the one identified in the acute assays. The observed ibuprofen genotoxic effects demonstrated an aquatic environmental risk of this pharmaceutical, which occurs for the used fish experimental model in lower concentration than previously described for other aquatic organisms.

SHELFLIFE OF FISHMEAL, PASTE AND CAKE OFTILAPIA NILOTICUSAND SUPPLEMENTATION OF CONVENTIONAL FISHMEAL WITH TILAPIA FISHMEAL IN THE DIET OFCLARIAS GARIEPINUSFINGERLINGS

The utilization of cheap, abundant, highly prolific T. nilotica (Oreochromis niloticus) for fish paste, cake and especially fishmeal in fish diets as an alternative to conventional fishmeal is tested in this study. Eight different preparations of T. niloticus fish paste were set up for 7 days. Also, dried fish cake and fishmeal were produced and kept for 3 months, part of the fishmeal were used in compounding six isonitrogenous diets with (0, 20, 40, 60, 80 and 100%) of 40% crude protein (CP) to feed Clarias gariepinus fry (0.52–0.73 g), stocking at 30 fry/bowl for 6 weeks. The unfermented, cooked, salted and frozen (at−25C) fish paste (super grade 1) of CP 52.13% was the best, because it did not change its physical appearance and still retained its natural seaweedy odor. The fish cake (CP 38.60%) and fishmeal (CP 65.70%) qualities were still well preserved at 3 months. The Tilapia fishmeal was tested by supplementing with conventional fishmeal on C. gariepinus diets for an experimental period of 6 weeks in order to determine the best level of utilization. Significant variations P < 0.05 occurred at all levels of diet treatments with Tilapia fishmeal (TFD) at 80% being the best-producing fish with highest specific growth rate (SGR; 3.68) and 0% TFD being the poorest producing fish with lowest SGR (1.61). PRACTICAL APPLICATIONS This study focused on the utilization and product development of available, cheap, abundant protein animal sources such as highly prolific Tilapia niloticus (Oreochromis niloticus) prepared into paste, cake and fishmeal. The fish paste especially the super grade 1 (crude protein [CP] 52.13%), which was salted, cooked and frozen, could be used as sauces and condiments in food and soup preparations. The super grade 1 Tilapia fish paste could be preserved for longer periods at −25C or at much lower temperatures. The fish cake (CP 38.15%) is an Irish potato flour based fish protein concentrate that could last for at least 3 months under storage in a cool dry place. Fish cake can be used as additives in animal feed formulation. The Tilapia fishmeal (CP 65.69%) is a good supplement for the expensive conventional fishmeal at 80% supplementation level, which produced the best growth performance in the diet of Clarias gariepinus fingerlings.

TOXIC EFFECT OF MALATHION IN TILAPIA NILOTICA

Toxic effect of malathion in Tilapia nilotica fish after short (one month) and long (5 months) term exposure as well as reversibility of the lesions were investigated. The result showed malthion has adverse effect on all vital organs of T. nilotica fish at both levels of exposure. Necrobiotic changes in the parenchyma of liver, kidney and heart Lamellar hyperplasia with lamellar fusion in gills and neuronal injuries and edema were all detected. Most of the lesions observed have been almost completely disappeared by 4weeks of withdrawal of malathion but the brain still showed focal subependymal edema accompanied with neuronal injury and edema of the nerve tract.

Assessment of toxicity and clastogenicity of sterigmatocystin in Egyptian Nile tilapia

The increasing presence of genotoxic pollutants in the aquatic environment has led to the development of quick monitoring methods. Sterigmatocystin (Stg) is closely related to mycotoxins and has the carcinogenic potency in the experimental animal models. The exposure to genotoxic agents will give rise to alterations of DNA structure that can lead to abnormal changes of DNA fingerprints. Therefore, we have applied the random amplified polymorphism DNA (RAPD) method to evaluate the genotoxic effects of Stg and to determine if the Egyptian montmorillonite (EM) has a protective effect against Stg. The experiment was conducted in vivo to evaluate the ability of EM at a level 0.5 mg/kg body weight (bw) to prevent the toxicity and genotoxicity induced by Stg in the Nile tilapia fish. Fishes were orally administrated with EM in corn oil with or without Stg (1.6 ig/kg bw) twice a week for 4 weeks. Blood and tissue samples were collected at the end of the treatment. The results revealed that Stg had genotoxic and toxicopathological effects in Oreochromis niloticus fish. The genotoxic effects were indicated by appearance of some changes in polymorphism band patterns including lost of stable bands or occurrence of new bands. There also exists a distinct distance between the band patterns of exposed fish and protected or control fish samples. The effects on the tissues were manifested by different histopathological lesions in different organs including hyperplastic proliferation of branchial epithelium, necrobiotic changes in hepatic tissue and destruction of components of the spleen. These responses were virtually abolished or markedly decreased when fishes were exposed to EM combined with Stg. It could be conclude that addition of EM resulted in the inhibition of the toxicity and clastogenicity of Stg

AUGMENTATION OF SPECIFIC AND NON-SPECIFIC PROTECTION IN OREOCHROMIS NILOTICUS TREATED WITH SOME PREBIOTICS AND / OR BACTERIN

We experimentally infected Oreochromis niloticus (O.niloticus) fish with Hafnia alvei (H.alvei), the causative agent of fish haemorrhagic septicemia in order to compare the immunological responses to differ-ent treatments with glucan, alginate and / or in combination with H.alvei bacterin. Elevations in the non-specific defence mechanisms were noted after O. niloticus were bathed in glucan, alginate, and bacterin solutions or in solutions containing the glucan or alginate combined with a bacterin. Blood samples were collected in several times showed an elevation in neutrophil activity through the ability of the cells to stick to glass and produce oxidative radicals where detected by the nitroblue tetrazolium (NBT) assay which increased after treatments in all groups within 48 hours. The numbers of circulatory glass-adherent cells from fish given the alginate, glucan and / or bacterin by bath was significantly higher than at the begining of the experiments or the control levels. Elevated phagocytosis, assessed by increased uptake of glutaraldhyde-treated sheep red blood cells, also confirmed these kinetics. It is obvious that fish given alginate and glucan in combination with bacterin, the kinetics of the non-specific and specific immune responses were significantly remarkable. The most promising group of immunostimulant are the alginate and the glucan and they could play an important role as imm-unomodulators in fish farming and in the prevention of diseases in fish cultures. This paper will present data on such effects with reference mainly to prebiotics and how can induce a systemic effect.

Adsorptive Properties of Fish Scales of Oreochromis Niloticus (Mojarra Tilapia) for Metallic Ion Removal from Waste Water

The present work presents the experimental study of the adsorptive properties for the removal of Cu2+ , Pb2+, Co2+, and Ni2+ metallic ions from water of thermally pretreated fish scales from a very common and abundant source in Mexico, the Oreachromis Niloticus fish, known as “Mojarra Tilapia”. To determine the influence and importance that the two main fractions (the organic or protein fraction and the inorganic fraction mainly composed of hydroxyapatite) of this material play in this adsorptive capacity, the original pretreated fish scales are subjected to an acid demineralization and a basic deproteinization treatment to modify the organic/inorganic matter ratios present, and their materials are characterized in terms of their adsorption ability, especially in the removal of the Cu2+ ion. The adsorption isotherms for the thermally pretreated fish scales show that they have a maximum Cu2+ adsorption capacity of 58 mg of Cu2+ /g of adsorbent with an ion selectivity removal in the order Cu2+ > Pb2+ > Co2+ > Ni2+. When the pure organic and inorganic parts of the fish scales are used in the adsorption experiments, the inorganic part has a 75% higher removal capacity than the organic fraction. The adsorption experiments using fish scales with different organic or inorganic fractions show a nonadditive, synergistic effect on the equilibrium amount of metallic ion adsorbed, which is independent of the inorganic content between 30 and 90 wt % of this inorganic fraction. Low-vacuum scanning electron microscopy and elemental analysis reveal that the ion-exchange reaction is the main mechanism for the metallic ion adsorption by fish scales.

Cadmium and lead levels in fish (Tilapia nilotica) tissues as biological indicator for lake water pollution.

Cadmium and lead were determined in different tissues (muscle, gill, stomach, intestine. liver, vertebral column and scales) of Tilapia nilotica from the High Dam Lake, Aswan (Egypt) to assess the lake water pollution with those toxic metals. Fish samples were chosen from different ages and weights to be analyzed along with samples of the aquatic plant (Najas armeta), sediment and lake water. The results showed that cadmium and lead concentrations were higher in fish scales and vertebral column than in the other parts of the fish. Cadmium and lead levels in High Dam lake water and fish (Tilapia nilotica) were a result of the pollution which uptakes from aquatic plants, sediments and gasoline containing lead that leaks from fishery boats. Tilapia nilotica fish was used as a good bio-assay indicator for the lake pollution with cadmium and lead. The fish muscles in this study were in the safety baseline levels for man consumption.

Effect of salting and drying conditions on quality of salted Dried tilapia ( Oreochromis niloticus ) fish

The effects of salting time, drying time and drying method on the moisture content, salt content and hardness of salted dried tilapia (Oreochromis niloticus) fish were investigated using a randomized complete block factorial design. Temperatures ranging from 29.0 - 35.5 °C were used for open air sun-drying and temperatures from 34 - 54 °C were used for solar drying. All the three process variables had significant effects (p = 0.05) on the moisture content of the salted dried fish, but the salting time had significant effect (p Journal of Applied Science and Technology (JAST) , Vol. 5, Nos. 1 & 2, 2000, pp. 156-161

Persistence and accumulation of some organic insecticides in Nile water and fish

The persistence and accumulation of organophosphate cyanophos (cyanox) and pirimiphos-methy (actellic) insecticides, and synthetic pyrethroid fenpropathrin (danitol) and cyfluthrin (baythroid) insecticides in Nile water and Tiplapia nilotica fish species were studied. The effect of boiling in water, as a method of cooking, on the studied insecticides was also examined. The sublethal doses of the insecticides were calculated and applied as a formulated type at rates of 2.5, 2.5, 0.001, and 0.001 ppm, respectively, to the species reared in a glass aquarium containing aerated tap water. The residues were determined at zero time (1 h), and 1, 3, 5, 7, 14, 21, and 28 days after application using HPLC technique. For organophosphorus insecticides, data revealed that the residue of cyanophos was 2.0 ppm after 1 day of application and then decreased to 0.002 ppm after 28 days. For pirimiphos-methyl it decreased from 2.1 to 0.01 ppm at the same time intervals. For pyrethroid insecticides, fenpropathrin and cyfluthrin showed similar rates of degradation. In fish flesh, the rates of accumulation of the studied insecticides varied. The rate of accumulation of cyanophos increased to 3.1 ppm after 3 days of application, while it was 2.7 ppm after 5 days for pirimiphos-methyl. On the other hand, the maximum rates of accumulation for fenpropathrin and cyfluthrin insecticides were 0.008 and 0.009 ppm after 5 days of application. Also, data indicated that boiling fish flesh in water at 100°C for 20 min removed considerable amounts of the insecticides.

Benzo[a]pyrene-induced hypocellularity of the pronephros in tilapia ( Oreochromis niloticus) is accompanied by alterations in stromal and parenchymal cells and by enhanced immune cell apoptosis

Numerous reports indicate that carcinogenic polycyclic aromatic hydrocarbons (PAH) are mammalian immunotoxicants. These environmental contaminants are widely distributed in both freshwater and costal marine ecosystems where they have been found to bioaccumulate in aquatic species, yet limited information exists regarding potential adverse effects of specific PAH on fish immune function. In the present report, Oreochromis niloticus fish (tilapia) were exposed by intraperitoneal injection to 5, 25, or 50 mg/kg of the PAH, benzo[a]pyrene (B[a]P). Histopathologic evaluation of the primary hematopoietic compartment of fish, the pronephros, demonstrated increased vacuolation of both stromal and parenchymal cells, reduction of lymphoid elements, and immune cell apoptosis. Total pronephros cell counts were diminished in a dose-dependent manner by the chemical exposure. The oxidative metabolic burst in phorbol myristate acetate (PMA)-simulated macrophages isolated from the pronephros was significantly inhibited by B[a]P, but only at the highest dose level employed. The phagocytic capacity of pronephros macrophages was not altered by the chemical treatment.

Estudos hematológicos em Oreochromis niloticus (Linnaeus, 1758) (Cichlidae, Teleostei) - Parte I

Avaliou-se o hemograma e a morfologia celular em amostras de sangue periférico obtidas de 10 peixes da espécie Oreochromis niloticus. Parte das mesmas foi utilizada para o estudo da hematimetria, isto é, contagem de eritrócitos (x = 2,35 x 106/mm3 ± 0,12), taxa de hemoglobina, (x = 7,04 g/dL ± 0,38), hematócrito (x = 27,85% ± 1,62), HCM (x = 30,31pg ± 1,64), VCM (x = 118,6p3 ± 3,53), CHCM (x = 25,78% ± 1,72), contagem global de leucócitos (x = 16,08 x 103/mm3 ± 1,28), contagem de trombócitos (x = 61,69 x 103/mm3 ± 5,96), sendo a avaliação da morfologia das células do sangue reallizada através do estudo de extensões sangüíneas submetidas à coloração de Wright. Os eritrócitos e trombócitos nucleados apresentaram-se elípticos; neutrófilos e eosinófilos esféricos de tamanho variável, com o núcleo também esférico, apresentaram citoplasmas abundantes, ligeiramente basófilo e altamente acidófilo, respectivamente. Não foram vistas as formas polimorfonucleares dessas células. Os basófilos apresentaram núcleo esférico e granuiações metacromáticas. Os monócitos e os linfócitos assemelharam-se morfologicamente aos dos mamíferos.

Determination of some metals in Clarias gariepinus (Cuvier and Vallenciennes), Cyprinus carpio (L.) and Oreochromis niloticus (L.) fishes in a polyculture fresh water pond and their environments

An investigation into the concentrations and distributions of zinc, lead, manganese, iron, copper, sodium, potassium and cobalt in the soil sediments, pond water and the organs of Clarias gariepinus (Cuvier and Vallenciennes), Cyprinus carpio (L.) and Oreochromis niloticus (L.) was undertaken with a view to evaluating the interplay of these inorganic minerals in the various matrices. The fishes have variable sizes while organs investigated in them were sex organs, gills, liver, intestine, eyes, head, scales, swim bladder and the trunk muscles, as appropriate. Copper and cobalt were not detected in any of the samples while other elements were more concentrated in the soil than in the water, while they were more concentrated in the fish organs than in water. Zinc, sodium and potassium values were higher in the fish organs than both in water and the soil sediments, thereby showing a high level of bioconcentration. The trace metals determined were below the deleterious level while the water quality was within the normal water quality for fresh water fishes.

Acute toxicity of Phytolacca dodecandra (Endod‐S) and Niclosamide to snails, Schistosoma mansoni cercaria, Tilapia fish, and soil microorganisms

AbstractThe acute toxicity of two molluscicides, the extract of the plant Phytolacca dodecandra (Endod‐S) and Niclosamide, was determined using the following test species: The snails Biomphalaria glabrata (albino) and Biomphalaria pfeifferi, Schistosoma mansoni cercaria, and Tilapia nilotica fish. Endod‐S showed a 24‐h LC50 of 2.57 and 5.37 mg/L for B. glabrata (albino) and B. pfeifferi respectively. Niclosamide produced a 24‐h LC50 of 0.063 mg/L and 0.049 mg/L for B. glabrata (albino) and B. pfeifferi, respectively. The 4‐h LC50 for S. mansoni cercaria was 2.92 mg/L for Endod‐S and 0.0008 mg/L for Niclosamide. The 24‐h LC50 for Tilapia nilotica was 1.82 mg/L for Endod‐S and 0.21 mg/L for Niclosamide. The toxicity of Endod‐S and Niclosamide to a mixed population of soil microorganisms was measured using oxygen uptake and growth as measured by turbidity. Endod‐S was not toxic to the microorganisms. The average Niclosamide toxic end point (IC50) for these bacteria was 450 mg/L.

Growth and Yield of Tilapia nilotica Fish and Rice in Irrigated Paddies

Growth and Yield of Tilapia nilotica Fish and Rice in Irrigated Paddies