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Adult Nile Tilapia (adult + nile_tilapia)

Distribution by Scientific Domains

Earth and Environmental Science	100%

Selected Abstracts

Isolation and characterization of strains of Flavobacterium columnare from Brazil

JOURNAL OF FISH DISEASES, Issue 4 2005
H C P Figueiredo
Abstract Flavobacterium columnare is an important pathogen of freshwater fish, implicated in skin and gill disease, often causing high mortality. An outbreak of skin disease in fingerling and adult Nile tilapia, Oreochromis niloticus (L.), cultivated in a recirculation system, was investigated. Four strains were isolated and characterized by biochemical reactions, enzyme production, fatty acid profile and analysis of the 16S-23S rDNA intergenic spacer region. All strains were identified as F. columnare. Experimental infection assays with one of these strains (BZ-5-02) were conducted and pathogenicity (by intramuscular route) was demonstrated in Nile tilapia and channel catfish, Ictalurus punctatus (Rafinesque). This is the first report of characterization of Brazilian strains of F. columnare. [source]

Optimization of flaxseed oil feeding time length in adult Nile tilapia (Oreochromis niloticus) as a function of muscle omega-3 fatty acids composition

AQUACULTURE NUTRITION, Issue 6 2009
I.B. TONIAL
Abstract This study evaluated the omega-3 (n-3) fatty acids and the proximate composition of muscle tissue of adult Nile tilapias to select the best feeding time length with a diet containing 70 (g kg,1 wt) flaxseed oil (FO). The results showed that dietary complementation with FO for 45 days is suitable for obtaining high levels of protein (164 g kg,1), total lipids (94 g kg,1), and ash (18 g kg,1). Furthermore, there was a significant difference (P < 0.05) in the reduction of n-6 and an increase in the concentration of n-3. With 45 days' time of FO feeding, fish weight was 532 g and it was improved by the incorporation of total n-3 (9.8%), consisting of alpha-linolenic acid (LNA; 6.3%), and n-3 very long-chain polyunsaturated fatty acid (n-3 VLC-PUFA; 3.5%), and including docosahexaenoic acid (DHA; 1.2%). This gave a better n-6/n-3 ratio (1.1) of muscle tissue, a more desirable ratio than the present ratio sometimes as high as 1 : 20 in human diets. The concentrations of n-3 VLC-PUFA were higher than those of native Brazilian freshwater fish. Thus, 45 days is the shortest time period required for the inclusion of FO oil in tilapia feed to raise the nutritional value of adult Nile tilapia. [source]

Influence of net cage fish cultures on the diversity of the zooplankton community in the Furnas hydroelectric reservoir, Areado, MG, Brazil

AQUACULTURE RESEARCH, Issue 7 2009
Renata M Dos Santos
Abstract The aim of this study was to examine the influence of the net cage system of fish culture on the composition, abundance and diversity of the zooplankton community. Comparisons were made between three collection points located near a group of 30 net cages, with individual volumes of approximately 4 m3, containing newly hatched, young and adult Nile tilapia, positioned in an arm of the Furnas hydroelectric reservoir; point 1 was in the limnetic region and points 2 and 3 were upstream and downstream of the cages, respectively, near the bank. The sampling was carried out at all three points from July to December, 2005. The composition of the zooplankton community differed among the points analysed. The lowest diversity was recorded at point 1. Point 2, upstream of the cages, was characterized by greater species richness and higher density of organisms pertaining to the Rotifera group. The results of the study suggest that variations in the composition and abundance of Rotifera and Cladocera are a consequence of the impact of net cage fish culture, although the magnitude of the variations is small. [source]

Effect of salinity on carrying capacity of adult Nile tilapia Oreochromis niloticus L. in recirculating systems

AQUACULTURE RESEARCH, Issue 16 2006
M A Kabir Chowdhury
Abstract Effect of salinity on carrying capacity of a recirculation system for Nile tilapia, Oreochromis niloticus L.; production was assessed. Survival, growth and feed conversion ratio of adult Nile tilapia fed 30% crude protein diet for 88 days were measured at three different salinity levels (8, 15 and 25 g L,1) and two stocking densities (20 and 40 m,3) in three independent recirculating systems. Highest survival (98%) and a linear growth in net biomass (P<0.01) was observed in both densities at 8 g L,1 and in 20 m,3 treatment at 15 g L,1. Highest net biomass growth was observed in the 40 m,3 stocking density treatment at 8 g L,1 salinity level (P<0.05). Overall biomass growth was significantly affected by salinity indicating a decrease in Nile tilapia carrying capacity with increased salinity. About 11 000 kg ha,1 crop,1 of Nile tilapia can be obtained in recirculating systems at 8 g L,1 salinity, significantly higher than the net production at 15 g L,1 (5200 kg ha,1 crop,1) and 22 g L,1 (4425 kg ha,1 crop,1). [source]