Thesis
Alternative live feeds and live feed enhancements for marine larviculture
Southern Cross University
Doctor of Philosophy (PhD), Southern Cross University
2021
DOI:
https://doi.org/10.25918/thesis.117
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Abstract
Oceans provide valuable resources, but as human populations increase there is a growing need for aquaculture to offset the wild harvest of marine animals. However, a persistent bottleneck in aquaculture production is larval rearing, often due to marine larvae receiving inadequate diets. This problem is particularly pronounced in the aquarium trade, where a lack of appropriate first feeds prevents the domestication of some highly valued fish species, and during portunid crab larviculture, where production is inconsistent due to poor larval nutrition. This thesis aims to diversify and improve marine larviculture techniques by exploring alternative live feeds and live feed enhancements. To achieve this, oyster larvae are first tested as a live feed for a small-mouthed ornamental fish larva that cannot consume traditional aquaculture live feeds. This thesis then examines whether the larval rearing of ornamental fish and portunid crabs can be improved by using a nutritious, but uncommon cryptomonad microalga as a live feed enhancement and greenwater. Key findings are: 1. Oyster larvae are readily consumed by <em>Parancanthurus hepatus</em>, a popular ornamental fish species too small to consume rotifers. However, oyster trochophores need to be conditioned in acidic seawater to compromise their shells and become digestible. 2. The cryptomonad microalga <em>Proteomonas sulcata is a better live feed enhancement than a commercial lipid emulsion for <em>Amphiprion latezonatus</em> larvae. This may be tied to high proportions of phospholipids and DPAn-6 in <em>P. sulcata</em>, and 3. The use of greenwater is highly beneficial when rearing <em>Portunus armatus</em> larvae, and survival and growth is best when using <em>P. sulcata</em> as the greenwater media. Surprisingly, when live feeds were enriched with a commercial lipid emulsion there were negligible effects on <em>P. armatus</em>, questioning the need to enrich live feeds when growing this species of crab.
Details
- Title
- Alternative live feeds and live feed enhancements for marine larviculture
- Creators
- Alexander John Basford
- Contributors
- Symon Dworjanyn (Supervisor) - Southern Cross UniversityBenjamin Mos (Supervisor) - Southern Cross University
- Awarding Institution
- Southern Cross University; Doctor of Philosophy (PhD)
- Theses
- Doctor of Philosophy (PhD), Southern Cross University
- Publisher
- Southern Cross University
- Number of pages
- xix, 179
- Identifiers
- 991012917800502368
- Copyright
- © AJ Basford 2021
- Academic Unit
- Faculty of Science and Engineering
- Resource Type
- Thesis