Please use this identifier to cite or link to this item: http://hdl.handle.net/1893/29327
Appears in Collections:Aquaculture eTheses
Title: Research and development to optimise hatchery production of ballan wrasse (Labrus bergylta): bacterial control and nutritional aspects
Author(s): Chalaris, Antonios Emm.
Supervisor(s): Migaud, Herve
Davie, Andrew
Keywords: Cleaner fish
egg disinfection
larviculture
diets
Bacillus
bronopol
digestive functions
Issue Date: Jul-2018
Publisher: University of Stirling
Abstract: Farmed ballan wrasse (Labrus bergylta) is recognised an efficient biological control of sea lice (Lepeophtheirus salmonis) infections in farmed Atlantic salmon (Salmo salar). Wild caught harvesting is putting increased pressure on wild stocks to meet growing demand, therefore, the production of disease free, farmed populations is a priority. Two main bottlenecks to be addressed are low larvae survival rates and slow juvenile growth during the hatchery phase. A first study compared egg disinfection protocols using bronopol as an alternative to the commercial use of formalin. Bronopol concentration of 100ppm applied for 240min on the first day of egg incubation followed by daily treatment with 25ppm for 30min is recommended for disinfection to control bacterial growth without affecting egg survival and hatching. A follow up study investigated the need for bacterial control at early larvae stages. Results showed positive effects of synergetic use of probiotics and bronopol on survival rate and microbial analyses identified opportunistic bacteria in the rearing environment and fish. The work then compared commercially available diets developed for weaning and on growing of other marine fish species. Benchmarking experiments confirmed the importance of developing ballan wrasse tailored diets based on specific raw materials, and provided a stepping stone to rationalise growth potential, feed intake, digestive and liver function, against which to compare in future studies. Clear differences in survival and growth were observed during weaning with improved survival in larvae weaned onto a diet including shrimp and cod fillet meal. During on-growing, results indicated improved FCR and growth compared to previous studies, potentially reducing time required to reach deployment size from 20–24 month to 16–19 month period. Overall, this study provides new knowledge that can be directly applied to help tackle major bottlenecks in commercial exploitation of farmed ballan wrasse.
Type: Thesis or Dissertation
URI: http://hdl.handle.net/1893/29327

Files in This Item:
File Description SizeFormat 
Research and development to optimise hatchery production of ballan wrasse_Chalaris A_PhD thesis.pdf2.56 MBAdobe PDFUnder Embargo until 2024-02-01    Request a copy

Note: If any of the files in this item are currently embargoed, you can request a copy directly from the author by clicking the padlock icon above. However, this facility is dependent on the depositor still being contactable at their original email address.



This item is protected by original copyright



Items in the Repository are protected by copyright, with all rights reserved, unless otherwise indicated.

If you believe that any material held in STORRE infringes copyright, please contact library@stir.ac.uk providing details and we will remove the Work from public display in STORRE and investigate your claim.