Beurteilende*r| Name: | Ao.Univ.Prof.i.R. Dr.phil. Herwig Waidbacher |
| Herkunftsbetrieb: | |
| Arbeit |
| Typ der Arbeit: | Masterarbeit |
| Sprache der Arbeit: | Englisch |
| Titel der Arbeit in Originalsprache: | Comparative assessment of growth performance of sex reversed Nile tilapia (Oreochromis niloticus) by fry immersion in freshwater and full seawater |
| Titel der Arbeit in deutsch: | Comparative assessment of growth performance of sex reversed Nile tilapia (Oreochromis niloticus) by fry immerion in freshwater and full seawater |
| Titel der Arbeit in englisch: | Comparative assessment of growth performance of sex reversed Nile tilapia (Oreochromis niloticus) by fry immersion in freshwater and full seawater |
| Publikationsmonat: | 06.2021 |
| Seitenanzahl: | 67 |
| Volltext |
| Volltext der Arbeit: | Volltext der Arbeit im PDF-Format laden |
| Online-Katalog der Universitätsbibliothek Bodenkultur |
| AC-Nummer: | AC16256673 |
| Abstract |
| Abstract in Deutsch: | Tilapia production for economic and food security has led to improved efficiencies in the industry with primary focus in all-male sex production. This study was conducted to compare growth performance of sex reversed Nile tilapia by fry immersion technique in both fresh and marine water. Survival rate of fry, sex reversal and growth rate of Nile tilapia was determined. Brood stock for fry production were selected at their respective grow out farms with monitoring done at KMFRI-Mombasa. Sex reversal was conducted through fry immersion in a solution of 17-α-methyltestosterone (MT) at different concentrations (0, 100 and 400 µg Lˉ¹), which served as control and treated groups. Fry immersion was conducted for 3 hours on the 1st and 3rd day post egg-yolk absorption. After immersion, 15 L aquaria were used and fry fed on artemia supplemented with omena dust. The laboratory phase was conducted for 28 days for both setups and 49 days for field setup for the freshwater. The marine field phase could not proceed due to setup breakdown. Liner pond was used for the freshwater setup and hapa nets of 1 m3 were randomly installed. Commercial feeds (35 % CP) were fed three times a day at 5 % body weight. The freshwater setup had a survival rate of 100 % while the marine setup had very low survival rates (5 %). Sex reversal was highest (91.5 %) in 400 µg MT Lˉ¹ and lowest in control (58.5 %). Treatment two showed better growth results for both the freshwater and marine setup with weight showing an interaction effect on the setups and treatments. The potential of the fry immersion technique is higher and different variables need to be considered for its improvement, efficiency and better results. With ever growing interest in the culture of tilapia in marine environment, and the findings of this study, key focus should be directed towards development of a breeding programme and capacity development on the same. |
| Abstract in Englisch: | Tilapia production for economic and food security has led to improved efficiencies in the industry with primary focus in all-male sex production. This study was conducted to compare growth performance of sex reversed Nile tilapia by fry immersion technique in both fresh and marine water. Survival rate of fry, sex reversal and growth rate of Nile tilapia was determined. Brood stock for fry production were selected at their respective grow out farms with monitoring done at KMFRI-Mombasa. Sex reversal was conducted through fry immersion in a solution of 17-α-methyltestosterone (MT) at different concentrations (0, 100 and 400 µg Lˉ¹), which served as control and treated groups. Fry immersion was conducted for 3 hours on the 1st and 3rd day post egg-yolk absorption. After immersion, 15 L aquaria were used and fry fed on artemia supplemented with omena dust. The laboratory phase was conducted for 28 days for both setups and 49 days for field setup for the freshwater. The marine field phase could not proceed due to setup breakdown. Liner pond was used for the freshwater setup and hapa nets of 1 m3 were randomly installed. Commercial feeds (35 % CP) were fed three times a day at 5 % body weight. The freshwater setup had a survival rate of 100 % while the marine setup had very low survival rates (5 %). Sex reversal was highest (91.5 %) in 400 µg MT Lˉ¹ and lowest in control (58.5 %). Treatment two showed better growth results for both the freshwater and marine setup with weight showing an interaction effect on the setups and treatments. The potential of the fry immersion technique is higher and different variables need to be considered for its improvement, efficiency and better results. With ever growing interest in the culture of tilapia in marine environment, and the findings of this study, key focus should be directed towards development of a breeding programme and capacity development on the same. |
| Schlagworte |
| Schlagwörter Deutsch: | fry immersion, methyltestosterone, tilapia saline culture |
| Schlagwörter Englisch: | fry immersion, methyltestosterone, tilapia saline culture |
| Sonstiges |
| Signatur: | D-22492 |
| Organisationseinheit, auf der die Arbeit eingereicht wird: | H81200 Institut für Hydrobiologie und Gewässermanagement (IHG) |
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