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Nile Tilapia Oreochromis Niloticus (nile + tilapia_oreochromi_niloticu)
Selected AbstractsProduction of Nile Tilapia Oreochromis niloticus and Freshwater Prawn Macrobrachium rosenbergii Stocked at Different Densities in Polyculture Systems in BrazilJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 3 2002Marcel J. M. dos Santos Twelve 0.01-ha earthen ponds were stocked with 1 tilapia/m2 and 0, 2, 4, or 6 postlarvae prawn/m2. Three replicates were randomly assigned to each prawn density. Postlarval prawns were stocked a week prior to tilapia juveniles and both were harvested 175 d after the beginning of the experiment. Tilapia final average weight, survival, production, and food conversion rates did not differ significantly among treatments (P > 0.05); the averages were 531 g, 67%. 3,673 kg/ha, and 1.91, respectively. Prawn survival rates did not differ for the three stocking densities (mean 90%). However, final weight and production were significantly different (P < 0.05) as follows: 34.0, 23.0, and 14.7 g and 639, 909, and 818 kg/ha, respectively for 2. 4, and 6 prawns/m2 densities. Stocking densities up to 6 prawn/m2 did not affect tilapia production and required neither additional feeding nor significant changes in management. The polyculture system allowed an increase in total production with the same amount of supplied feed, thus improving the system sustainability. [source] Physiological responses in Nile tilapia exposed to different photoperiod regimesJOURNAL OF FISH BIOLOGY, Issue 3 2004A. K. Biswas After conditioning Nile tilapia Oreochromis niloticus for 2 weeks, the photoperiod regime of 12 tanks of fish was changed to a 6L : 6D photoperiod while 12 further tanks were retained on the conditioning photoperiod regime (12L : 12D). Blood samples were collected 3 days (first sampling) and 3 months (second sampling) after changing the photoperiod regime. Blood was collected at 6 h intervals from both photoperiod regimes (1000, 1600, 2200 and 0400 hours). At the first sampling time, fish in the 6L : 6D had significantly higher cortisol both in the light and dark phases than levels in fish in the 12L : 12D photoperiod. At the second sampling time, the levels were significantly higher only in the light phase. The levels of cortisol, glucose and Cl, in fish exposed to the 6L : 6D photoperiod, however, were far lower than those of acute stress-induced levels observed in fish exposed to a stress experiment. Furthermore, there were no significant differences in overall values of all the variables between the photoperiod regimes at the second sampling time. This indicated that the fish exposed to the 6L : 6D photoperiod were not chronically stressed. Significantly higher blood lymphocyte counts were observed in fish exposed to the 6L : 6D compared to those of the 12L : 12D photoperiod during the light phase at the second sampling time. Other variables (glucose, Cl,, haematocrit and neutrophil) did not show a significant difference between the treatments at either sampling time. These results demonstrated that the artificial photoperiod regime did not cause a significant acute or chronic stress response in Nile tilapia. [source] Conditioning of stress in Nile tilapiaJOURNAL OF FISH BIOLOGY, Issue 4 2004P. S. A. Moreira A Pavlovian conditioning paradigm was used to induce a connection between a conditioned stimulus, light (CS), associated with an unconditioned stimulus, confinement (US) in Nile tilapia Oreochromis niloticus, which resulted in a conditioned endocrine response (CR) to the CS alone manifested as an increase in plasma cortisol. Individual isolated Nile tilapia were submitted for 10 days to the conditioning treatment consisting of turning on a light (CS) for 1 min with subsequent 30 min confinement (US). On the 10th day of the experiment, plasma cortisol was not increased when fish were subjected to no handling at all, or only light, or even a daily stressor for the 9 days. On the other hand, at the 10th day cortisol was significantly increased only when light was presented either with or without pairing with the stressor. These results confirmed that the cue, light (CS), was not stressful in itself, but when given as the CS in the absence of the US post conditioning the hypothalamus,pituitary,interrenal axis was activated. Therefore, it was concluded that memory of a previous experience with a stressor can be recalled by a conditioned stimulus and induce stress, which is the first demonstration of a memory-induced stress in fishes. [source] Complete replacement of fish meal by porcine and poultry by-product meals in practical diets for fingerling Nile tilapia Oreochromis niloticus: digestibility and growth performanceAQUACULTURE NUTRITION, Issue 1 2010C. HERNÁNDEZ Abstract The apparent digestibility coefficients (ADC) of poultry by-product meal-pet food grade (PBM) and porcine meal (PM) were determined for fingerling male Nile tilapia. ADC for protein were 98.1% and 92.3% in PBM and PM, and 87.1% and 79.4% for energy. PBM and PM were then used as complete replacements for fish meal (FM) in practical diets for Nile tilapia formulated to contain equal digestible protein (300 g kg,1) and energy (16.74 MJ per 100 g) on an as-fed basis. Fingerlings (mean initial weight ±SD, 9.5 ± 0.015 g) were fed for 8 weeks on one of the four diets: FM-, PBM- or PM-based and a commercial feed. The ADC for protein in control and PBM diets (89.7% and 87.9%) were significantly higher than those for the control diet (81.96%). Growth performance and feed utilization were statistically similar between fish fed control and PBM diets, whereas the PM diet exhibited significantly lower performance compared with the control. However, the PM diet showed similar results to the commercial reference diet. Survival and feed conversion ratio were not significantly influenced by replacement of FM with either PBM or PM. The results indicated that PBM and PM can effectively replace FM in practical diets for fingerling Nile tilapia. [source] Introduction of jundia Rhamdia quelen (Quoy & Gaimard) and Nile tilapia Oreochromis niloticus (Linnaeus) increases the productivity of carp polyculture in southern BrazilAQUACULTURE RESEARCH, Issue 5 2008Leonardo Bolognesi Da Silva Abstract Fish polyculture is based on the assumption that each species has its own feeding niche and may increase the maximum standing crop of a pond by exploring a wider range of available food and ecological niches. In order to identify the better species ratio and to introduce jundia (JN) (Rhamdia quelen Quoy & Gaimard) and Nile tilapia (NT) (Oreochromis niloticus Linnaeus) in to the carp polyculture practiced in South Brazil, a 162-day experiment was conducted, in 12 250-m2 earthen ponds (1.2 m deep). Treatment I (T-I) contained 35% common carp, Cyprinus carpio (L.) (CC); 35% grass carp, Ctenopharyngodon idella Valenciennes (GC); 15% silver carp, Hypophthalmichthys molitrix Valenciennes (SC); and 15% bighead carp, Aristichthys nobilis Richardson (BC). Treatment II (T-II) consisted of three ponds stocked at the following ratio: 17.5% CC, 35% GC, 15% SC, 15% BC and 17.5% JN. Treatment III (T-III) consisted of three ponds with 35% CC, 35% GC, 7.5% SC, 7.5% BC and 15% NT. Treatment IV (T-IV) consisted of three ponds with 17.5% CC, 35% GC, 7.5% SC, 7.5% BC%, 17.5% JN and 15% NT. No significant correlation was found between the treatments with different species ratio and water quality parameters. The final weight of different species, in different treatments, was statistically different. The major result was the clear positive effect on growth parameters observed by the introduction of JN and/or NT in to the carp polyculture. The yield per hectare was 2083.33±183 kg ha,1 for polyculture with carp species; 2476.67±139.88 kg ha,1 following the introduction of JN only; 2801.67±111.42 kg ha,1 for isolated introduction of NT; and 2506.67±422.31 kg ha,1 for simultaneous introduction of JN and NT. The introduction of JN and/or NT had a positive effect on growth parameters when compared with carp-only polyculture. The reduction in CC ratio also had a positive effect on growth parameters. [source] Effect of dietary probiotic Biogen® supplementation as a growth promoter on growth performance and feed utilization of Nile tilapia Oreochromis niloticus (L.)AQUACULTURE RESEARCH, Issue 14 2006E R EL-Haroun Abstract Probiotic microbial feed supplements are gaining wide acceptance in livestock production, and may be applicable to aquaculture production systems. The present study was conducted to examine probiotic treatment in the fingerling diet of Nile tilapia Oreochromis niloticus (L.). A total of 240 of Nile tilapia fingerlings (weight ranged from 22.96 to 26.40 g) were divided into five experimental groups. The experiment was conducted for 120 days. Experimental diets were identical in all, except for the variation in probiotic levels. A probiotic (Biogen®) was used at 0% (diet 1), 0.5% (diet 2), 1.5% (diet 3), 2.0% (diet 4) and 2.5% (diet 5) inclusion rates in the experimental diets. The growth performance and nutrient utilization of Nile tilapia including weight gain, specific growth rate, protein efficiency ratio, protein productive value and energy retention were significantly (P,0.01) higher in the treatment receiving probiotic (Biogen®) than the control diet. No differences were observed for moisture, ash and protein content (P,0.01) among the experimental diets. The lowest gross energy and lipid contents were recorded for fish fed the diet containing 0.5% Biogen® (P,0.01). The production performance and subsequent cost,benefit analyses clearly indicated that the diets containing probiotic biogen recorded the highest net return and the lowest total cost compared with the control diet. [source] Effect of temperature and phytoplankton concentration on Nile tilapia Oreochromis niloticus (L.) filtration rateAQUACULTURE RESEARCH, Issue 6 2003Hakan Turker Abstract Nile tilapia Oreochromis niloticus (L.) held in timed-pulse feeding chambers, were provided with algal-rich water dominated by either green algae (Scenedesmus, Ankistrodesmus, Chlorella and Tetraedron) or cyanobacteria (Microcystis) to determine the effect of temperature and phytoplankton concentration on filtration rates. Green algae and cyanobacteria filtration rates were measured as suspended particulate organic carbon (POC) kg,1 wet fish weight h,1. Ivlev's filter-feeding model described the relationships between filtration rates and suspended POC concentration of green algae and cyanobacteria. Filtration rates of both green algae and cyanobacteria increased linearly as water temperature increased from 17 °C to 32 °C and were significantly higher in the warm-water regime (26,32 °C) than in the cool-water regime (17,23 °C). Filtration rates at 95% saturation POC (FR95) in green algal and cyanobacterial waters were 700 mg C kg,1 h,1 and 851 mg C kg,1 h,1 in the warm-water regime and 369 mg C kg,1 h,1 and 439 mg C kg,1 h,1 in the cool-water regime respectively. The FR95 in warm water were achieved at lower POC concentrations than in cool water. [source] Overwintering performance of Nile tilapia Oreochromis niloticus (L.) broodfish and seed at ambient temperatures in northern VietnamAQUACULTURE RESEARCH, Issue 6 2000N C Dan Two experiments (E1 and E2) to assess the performance of tilapia broodstock and tilapia sex-reversed fry in overwintering were conducted at the Research Institute for Aquaculture No.1 (RIA-1) in the cold seasons of 1995,96 and 1996,97. Nile tilapia Oreochromis niloticus (L.) broodstock of the Thai, GIFT, Egypt and Viet strains were overwintered in deep and shallow ponds, as well as in deep and shallow hapas suspended in a single deep pond for evaluation of the influence of overwintering systems on the survival and growth of fish. Large (> 1 g) and small (< 1 g) tilapia seed were overwintered in deep hapas-in-ponds for comparison of their performance. In 1995,96, the coldest pond water temperature was 10,11 °C, and survival of tilapia broodfish overwintered in deep and shallow hapas-in-ponds was 99.6,100%. This was significantly (P < 0.05) higher than fish stocked in deep and shallow ponds (74.4,90%). The survival rate of larger monosex tilapia fry was 54%, which was significantly (P < 0.05) higher than that of smaller fry (33.4%). In 1996,97, the lowest pond water temperature was 15.8 °C, and fry showed similarly high survival rates in all treatments (97,100%). There was no significant difference between fry in the two size classes. The results of this study clearly indicate that hapas-in-ponds are useful for reducing the risk and improving the survival of tilapia broodstock and fry in the cold season. Differences in the decline in ambient temperatures year on year mean that the need for special overwintering conditions varies. Hapas-in-ponds are a low-cost overwintering method that can be one of the appropriate strategies for tilapia seed production under the variable, cool temperature regimes in northern Vietnam. [source] | ||||||||||