- Title
- Macroalgal Cultivation and Growth of Weaning Juvenile South African Farmed Abalone Haliotis Midae
- Creator
- Sanele Qondani
- Description
- ABSTRACT Haliotis midae Linnaeus, 1758 is the largest among six abalone species found in South Africa, making it the second largest around the world. This species is highly sought after due to its size and delicacy. However, it’s expensive formulated feed and slow growth rate has prompted increasing research on improving its growth using natural feeds. Inclusion of fresh and dried macroalgae (Ulva lactuca Linnaeus, 1753 and Gracilaria gracilis Irvine & Farnham, 1995) onto artificially formulated feed (Abfeed®) was tested on the growth of juvenile weaning H. midae. Therefore the three treatments were referred to as: Abfeed®, Abfeed® plus fresh seaweed and Abfeed® plus dried macroalgae. The growth of U. lactuca and G. gracilis was also compared using four different liquid fertilizers. Results revealed that inclusion of dried macroalgae was the best feed as it showed better consumption (92±0.48%) and growth (SGR = 2.9±0.04 % g. day-1 , DISL = 12.04±0.48 µm. day-1 and CF= 0.97±0.07 g. mm-1 ) rates. The study exhibited no differences in survival rate and feed conversion ratio in all the treatments used. Enriching with different fertilizers at 10 % concentration revealed that Nutrisol® promoted the best growth for U. lactuca among four different fertilizers used while Kelpak® yielded the best growth for G. gracilis. Increasing concentrations to 20 % resulted in Nitrosol® performing better than other fertilizers in U. lactuca growth while G. gracilis grew best in Nitrosol® and Kelpak®. This study therefore demonstrates the potential to develop abalone feeds with inclusions of dried macroalgae meal. Abfeed® as a diet alone performed poorly against the feeds tested as expected due to many previous studies favoring mixed diet. The study further revealed that macronutrient (nitrogen and phosphorus) is the limiting ii factor for macroalgal growth and their level in culture system is very critical as it determines growth rate. Key words: Consumption rate, Feed conversion ratio, Fertilizer, Formulated feed, Survival rate
- Date
- 2018
- Type
- Master
- Identifier
- http://hdl.handle.net/11260/2765
- Identifier
- vital:42860
- Contributor
- T. S. Dlaza, M. Naylor
- Publisher
- Walter Sisulu University
- Language
- English
- Rights
- Walter Sisulu University
- Hits: 401
- Visitors: 415
- Downloads: 72
Collections
WSU Department of Biological and Environmental Sciences
| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | SANELE QONDANI-MSc Research Output.pdf | 2 MB | Adobe Acrobat PDF | View Details Download |