923 resultados para Tilapia (Peixe) - Fisiologia
Resumo:
Tilapia once termed "poor man's" fish, still remains as the highly-priced food fish in many developing countries. The good attributes of this fish prompt its use in intensive aquaculture vertically integrated systems (VIS) which embrace broodstock development, hatchery/nursery and growout phase. Based on the series of studies carried out at Kainji Lake Research Institute, in New Bussa, Nigeria using Oreochromis (Tilapia niloticus) in floating bamboo hapas/cages, the recommended intensive modular systems were estimated to be capable of producing 4 million Tilapia fingerlings and 729 tons fish (Market-size) annually. Cost-benefit analysis showed the venture to have high prospects. It is recommended that priority be given to Tilapia cage culture at the national level in order to contribute immensely towards increased fish production
Resumo:
The digestibility and utilisation of two soybean bran-based diets and two fishmeal-based diets serving as control, at optimal (30%) and suboptimal (20%) protein levels were evaluated in Oreochromis niloticus. These were Diet I (Control)-fishmeal based diet at 30% crude protein, Diet II (Control) - fishmeal based diet at 20% crude protein, Diet III - hydrolysed Soybean Bran based diet at 30% crude protein, Diet IV - hydrolysed Soybean Bran based diet at 20%. Dry matter digestibility differed insignificantly with variation in diets (P<0.05). There was significant variation in the protein (p 20.05), lipid and ash digestibility. Protein was more digestible at optimum level than sub-optimum level, while lipid and ash digestibility did not vary with their inclusion levels. Variation in the utilisation of the diets was significant (P<0.05) except for survival. It was observed that the best diet was Diet 1, closely followed by Diet II with highest values of mean final weight, specific growth rate, protein efficiency ratio and the apparent net protein utilisation. The high digestibility values of Diets III and IV suggests their inclusion in fish diet to spare protein for growth
Resumo:
The food and feeding habits of Tilapia zillii in the fish farm of Ondo State University, Akungba - Akoko, Nigeria, were studied by gut analysis. Examinations of 150 specimens showed that Nymphea formed the main bulk of food consumed. Spirogyra, Pithophora and Compsopogon occurred frequently while Pistia detritus and plant remains featured less frequently. Variation in the frequency of occurrence of the various food items was observed among the various sizes of samples. The samples within the middle - size group fed on both higher plant and filamentous algae while the young and higher fish consumed exclusively filamentous algae. On the basis of food items found in the gut, Tilapia zillii was classified as primary consumers
Resumo:
Acute toxicity tests on the effects of Gramoxone and detergent (both applied as a single dose) to nile tilapia, Oreochromis niloticus, fingerlings (mean weight 2.7~c1 g) were conducted using static bioassay. The 96-h LC sub(50) of Gramoxone and detergent applied were 0.08ml/l and 0.004 g/l, respectively. The fingerlings showed increased hyperactivities exemplified by erratic movement, loss of reflex, and hyperventilation during the period of exposure. These effects increased with increasing concentrations of Gramoxone or detergent throughout the duration of exposure. Tilapia fingerlings of the same size showed different levels of tolerance to the same concentration of both pollutants
Resumo:
The fisheries of Lake Kainji, Nigeria, experienced a boom year following impoundment, then decline post impoundment and now is in a period of stabilisation of the fish resources. Several reasons have been advanced on factors responsible for these changes, but two outstanding factors are those of nutritional status and fishing methods of the lake. Two important fish families however continue to dominate the lake fisheries in daily fisherman catches: Clupeidae and Cichlidae (tilapias). Recent studies have also shown that the dominance of the tilapias and clupeids is an important factor in the understanding of the stability of fisheries of Lake Kainji. One area which has remained undiscussed concerns the parasites and non-fish predators of tilapias which can affect the population dynamics of tilapias. This paper examines therefore some aspects of the fisheries of Lake Kainji and the potential roles that parasites and non-fish predators of tilapias can contribute in developing strategies for consideration in the sustainable management of the fisheries
Resumo:
The carbohydrate, protein and lipid contents of the food ingested and their absorption in the intestine of Sarotherodon melanotheron inhabiting Awba lake in Ibadan, Nigeria, were investigated. Total carbohydrates of the ingested food ranged from 39.33 to 55.38% (mean = 48.70% while total protein and total lipid ranged from 10.10 to 17.13% (mean = 12.91%) and 7.79 to 8.96% (mean = 8.28%) dry weight, respectively. Calculated total percentages absorbed were 54.86-62.01 (mean 58.07) carbohydrates 47.33-54.06 (mean = 50.43) protein and 43.27-52.23% (mean 46.56) lipid. Absorption of protein and carbohydrate occurred mostly in the fore-gut (the first one-third of the intestine), while lipid was mostly absorbed in the mid-gut (the second one-third of the intestine). Dietary carbohydrate, protein and lipid contents of the food as well as the absorptive capacity of the intestine for these components of the food varied with size of fish
Resumo:
A total of sixty juvenile Oreochromis niloticus (Nile tilapia) were fed three species of aquatic weed, namely Azolla filiculoides (water fern), Elodea sp. and Pistia stratiotes (water lettuce) to determine which of the weeds will be selectively consumed, and preferred of all. A control group of twenty Nile tilapia was fed compounded feed. The selectivity of the weeds was observed based on their utilization as food source, and Azolla filiculoides was found to be highly utilized, followed by Elodea sp. and the roots of Pistia stratiotes. The growth response of the fish to the diets was found to be highest for fish fed compounded feed followed by Azolla filiculoides and Elodea sp., while Pistia stratiotes produced a negative growth trend. It is therefore postulated that Azolla filiculoides and Pista sp. are good feedstuffs for O. niloticus especially when used together with other feedstuffs
Resumo:
Production of mince from Tilapia using a combination of physical and chemical methods was found to improve the storage life of the mince in the deep freezer. Though the chemical composition of the mince was slightly affected, the mince was microbiologically stable throughout the five weeks frozen storage. Fish cakes prepared traditionally from tilapia minces were more acceptable than oven dried cakes. Production of fish cakes form tilapia will improve utilization of this species in areas where small size tilapia are regarded as fish of low economic value
Resumo:
Orain arte eskaladaren inguruan dagoen literaturan, antropometria, heltze indarra eta erantzun psikofisiologikoak aztertu dira nagusiki eta kontraesan ugari aurkitzen dira autore ezberdinen artean. Ikerketa honen bidez, kontraesan guzti hauek argitu nahi dira eta balorazio proba berri batzuen eraginkontarsuna aztertu. Gradu amaierako lan honen helburuak, lau balorazio proba ezberdin diseinatu, gauzatzea (heltze indarra, gauzatze aldagaiak, erantzun fisiologikoak eta RPE neurtuz) eta neurketa antropometrikoak egitea izan dira. Ondoren, maila ezberdineko eskalatzaileen eta bi sexuen arteko ezberdintasunak behatzeko. Ikerketan hiru emakume eta bederatzi gizonek parte hartu zuten, uniformeki maila ezberdineko taldetan banaturik. 1.taldea (6.gradukoak), emakume bat eta bi gizonek osatzen zuten, 2.taldea (7.gradukoak), emakume bat eta hiru gizonek eta 3.taldea (8.gradukoak), emakume bat eta lau gizonek. Diseinaturiko lau balorazio probak honako hauek izan ziren: 1.proba, suspentsio maximoa 1,8mmko regletan; 2.proba, trakzio kopuru maximoa; 3.proba, 7a zailtasuneko bia bat eskalatu akidura arte eta 4.proba, 6a+ zailtasuneko bia bat eskalatu akidura arte. Balorazio proba edo testekin hasi aurretik, atsedenean, bihotz maiztasuna eta tentsio arteriala neurtu eta esperientzia eta kirol praktikaren galdetegi bat pasa zitzaien. Ondoren, balorazio proba bakoitzaren aurretik eta ostean, gauzatze aldagaiak, heltze indarra, erantzun fisiologikoa eta RPE neurtu zitzaien. Erantzunei dagokionez, perfil antropometrikoan, gero eta maila altuagoko eskalatzaileek endomorfia baxuagoa dute eta emakumeek gizonezkoek baino balore altuagoak dituzte aldagai guztietan, gantz portzentaian izan ezik. Heltze indarrean aldiz, ez zen ezberdintasun adierazgarririk topatu hiru taldeen artean eta gizonezkoek emakumezkoek baino balore altuagoak izan arren, indar galera antzekoa dute. Erantzun fisiologikoetan ez zen ezberdintasun adierazgarririk topatu. Suspentsio maximoan (1.balorazio proban), gero eta maila altuagoko eskalatzaileek denbora gehiago irauten dute suspentsioan, trakzio kopuruetan aldiz (2.balorazio proba), ez dago ezberdintasun adierazgarririk. Kirol eskalada bertikalean aldiz (3. eta 4. balorazio probetan), maila altuagokoek distantzia luzeagoak eta mugimendu kopuru gehiago egiten dituzte proportzionalki denbora laburragoan. Ondorioz, helburuetako batzuk neurri handi batean bete dira. Laburbilduz, diseinaturiko balorazio probak erabilgarriak dira azkena izan ezik, eta antropometrian, heltze indarrean, suspentsio maximoan eta 3. balorazio probako gauzatze aldagaietan ezberdintasun adierazgarriak topatu dira.
Resumo:
Replicate Ponds of 0.02ha stocked at 500 catfishes with 20,000 tilapia/ha were used to assess growth performance of O.niloticus, average weight 50.4g with (i) darted catfish; H.longifilis (shooters) average weight 60.3g (ii) non-shooters of H.longifilis, average weight 35.4g. Final mean weight, mean growth rate, specific growth rate and food conversion ratio were 499.5g 26g/day, 1.36% and 5.58% respectively for O.niloticus stocked with longifilis (shooters and 440.4g 2.3g/day 1.23% and 5.58% respectively for O.niloticus stocked withH.longifilis (non- shooters) and 246.9g, 1.2g/day, 0.93, 6.30% respectively for tilapia in monoculture. The least growth was noted for O. niloticus in monoculture while the best growth was recorded O. niloticus in polyculture with darted catfish
Resumo:
The effects of some environmental factors on the fecundity of Tilapia species (Family Cichilidae) was carried out at the Kigera dam. Four Tilapia species caught were Tilapia zilli, Hemichromis fasciatus, Sarotherodon galilaeus and Oreochromis niloticus while the environmental factors considered were water temperature, Dissolved Oxygen, pH value, level of rainfall and rate of sunshine and range of time. 43 fish comprising of 25 male with (58.1%) and 18 females having (41.9%) were studied with 74.42% been sexually matured. Both high levels of rainfall and dissolved oxygen favoured fecundity. The spawning peak occurred in (July), environmental factors monitored indicated that dissolved oxygen ranges from 3.7 to 4.45mg/lit rainfall ranges from (34.90mm to 237.80mm) sunshine ranges from (5hrs-8hrs) and pH ranges from (7.35-7.45). The spawning of these species in their natural or hatchery condition is therefore best achieved during the peak of raining season
Resumo:
Replicate Ponds of 0.02ha stocked at 500 catfishes with 20,000 tilapia/ha were used to assess growth performance of O.niloticus, average weight 50.4g with (i) darted catfish; H.longifilis (shooters) average weight 60.3g (ii) non-shooters of H.longifilis, average weight 35.4g. Final mean weight, mean growth rate, specific growth rate and food conversion ratio were 499.5g 26g/day, 1.36% and 5.58% respectively for O.niloticus stocked with longifilis (shooters) and 440.4g 2.3g/day 1.23% and 5.58% respectively for O.niloticus stocked with H.longifilis (non- shooters) and 246.9g, 1.2g/day, 0.93, 6.30% respectively for tilapia in monoculture. The least growth was noted for O. niloticus in monoculture while the best growth was recorded O. niloticus in polyculture with darted catfish
Resumo:
The effects of substituting fish meal with grasshopper meal in fish diets on the growth, food utilization and survival of the Nile tilapia, Oreochromis niloticus (mean weight = 40.1g) were investigated. The results show that the best growth and food utilization were recorded in the fingerlings fed in the 10% grasshopper meal and 30% fish meal while the poorest growth and food utilization indexes were recorded with the 25% grasshopper meal and 15% fish meal. In general, at 10% inclusion, the fingerlings performed even better than the control (40% fishmeal and no grasshopper meal)
Resumo:
Among plant protein ingredients,ipil ipil (Leucaena leucocephala) leafmeal (ILLM) is considered the most nutritive plant protein source after soybean meal in aquatic feeds. That was proven in a 21-day experiment conducted to assess the response of juvenile Monosex Nile tilapia Oreochromis niloticus with four iso-nitrogenous formulated diets: One control diet was formulated based on fishmeal, one on soybean meal and one on rice bran, ipil ipil leafmeal was also included in experimental diets.
Resumo:
The Ipil-ipil (Leucaena leucocephal) leaf analyzed for crude protein (CP), fat, crude fibre (CF), ash content, moisture content and nitrogen free extract (NFE). The CP 23± 0.12 % , fat 8 ± 0.11 %, CF 18 ± 0.15 % , ash 10 ± 0.13 %, moisture 14. ± .16% and NFE 29.± 1.10 % were recorded. A twenty one days experiment was conduced to assess the response of juvenile monosex tilapia with different iso-nitrogenous formulated diets for find out the feasibility study of using ipil-ipil leaf meals as feed ingredient for juvenile tilapia. Three experimental diets were formulated by using fish meal, soybean meal, rice bran and ipil ipil leaf meal. One control diet was formulated by using fish meal, soybean meal and rice bran. Considering the high demand, limited availability of fish meal and soybean meal, ipil ipil leaf meal was incorporated in juvenile tilapia feed. Among plant protein ingredients ipil ipil leaf meal was considered as the most nutritive plant protein source after soybean meal. However, high concentration of toxic element limited the incorporation level of ipil ipil leaf meal in fish feed. Use of 15 % ipil ipil leaf meal in fish feed was more significant from the view of growth performance and economics. The higher Absolute Growth was 1119.26 gm, higher Specific Growth Rate was 6.52% /day higher Feed Conversion Efficiency was 41.23% , higher Protein Efficiency Ratio was 1.178 and higher Average Daily Growth rate was 14.00% recorded in diet-4 ( which contained 15% IILM). The lower Feed Conversion Ratio 2.42 and lower cost for per unit production 34.65 taka/kg were recorded in diet-4. The higher cost for per unit fish production 45.6 tk./kg was recorded for diet-1 where no ipil ipil leaf meal.. The results suggest that tree legumes Ipil-ipil (Leucaena leucocephal) leaf has potential and excellent source of feed ingredients as protein supplements for juvenile monosex