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Lumpfish (Hatchery (Feeding (Effects of different feeding frequencies on…
Lumpfish
Hatchery
Temperature
Effect of incubation temp. on eggs and larvae of lumpfish (Imsland, 2019)
- Very good study, concluded that lumpfish eggs incubated at a temp. gradient were best.
- Lots of comparisons to studies of other fish species
Feeding
Effects of different feeding frequencies on growth, cataract development and histopathology of lumpfish (Imsland, 2019)
- Compared 3 groups of lumpfish fed daily, 4DW and 3DW
- 3DW had less cataracts and were healthier
- 3DW were smaller which is good as they are more efficient cleaners and reach sexual maturity slower
- More research to see the combination of reduced feeding frequency and reduced ration size
Effects of three commercial diets on growth, cataract development and histopathology of lumpfish (Imsland, 2018)
- Compared 3 diets
- Found that fish fed C were smaller and had more cataracts
- The authors suggest that vitamin C and/or astaxnthin may play a role
An epidemiological study of cataracts in wild and farmed lumpfish and the relation to nutrition (Jonassen, 2017)
- Cataracts are commonly linked to water quality and nutrition (husbandry practice)
- severe cataract will lead to reduced feeding and growth
- Wild lumpfish got cataracts significantly less than farmed
- Physiological need for NAH (Na- Acetyl-l-Histidine) in the lens
- Cataracts probably linked to nutrition as high levels of amino acids are found in tissues leading to osmotic imbalance and thus, cataracts
Reproduction
The use of photoperiods to provide year round spawning in lumpfish (Imsland, 2019)
- Photoperiod does effect lumpfish maturation
- More studies could result in a year round egg supply
The effect of continuous light and compressed photoperiods on growth and maturation in lumpfish (Imsland, 2018)
- The first study to look at light and lumpfish
- Model based off other Atlantic cod
- There is a change but needs to refined further
Use of lumpfish for sea-lice control in salmon farming: challenges and opportunities (Powell, 2018)
- In the wild, adults breed over rocks in the winter and typically mature at 3-5 years
- For broodstock, adults are captured during spawning using gill nets (less damaging methods e.g. SCUBA are not as efficient
- Captive fertilisation (dry method) involves mixing sperm and eggs then using sea water as an activator
- This involves the culling of males (not long term solution)
- If the females spawn naturally, the eggs have lower survival as they are harder to incubate
- Artificial fertilisation is recommended
Artificial fertilisation
- Wild caught broodstocks are quarantined and treated
- Gametes stripped and fertilised (adults killed or used again)
- Embryos maintained until hatching
- Hatchlings reared in low flow tanks (3-4 months)
- Juveniles continue to grow in increased flow tanks
- Fish are either deployed in salmon pens or selected for broodstock
Disease
Exophiala angulospora infection in hatchery-reared lumpfish broodstock (Saravia, 2019)
- Vulnerable to many diseases including fungus infections in Scotland, Norway and Ireland. (no effective treatment)
- Lumpfish did not show signs of morbidity or diminished swimming activity but had dark lesions externally and on internal organs (particularly the kidney)
- Not known to impact them in the wild
- Lumpfish are prone to it after spawning e.g they are tired and have a lower immune system
Use of lumpfish for sea-lice control in salmon farming: challenges and opportunities (Powell, 2018)
- Fungal infections cause systemic hyphen growth in the musculature, gills and internal organs
- Cases have been found in the wild caught fish (contradiction to Saravia,2019)
- Microsporidia- fungi detected in wild lumpfish, no effective treatment
- More research is needed
- Gives details on Myxosporea, ciliates, amoebic gill disease, bacterial diseases, flukes, sea lice, parasitic worms and eye cataracts
In the cage
Use of lumpfish for sea-lice control in salmon farming: challenges and opportunities (Powell, 2018)
- Looks at welfare in cages
- Feeding preferences
Harvesting
Use of lumpfish for sea-lice control in salmon farming: challenges and opportunities (Powell, 2018)
- Re-use of lumpfish post deployment is an area that needs more research as culling after one cycle is wasteful
- Harvest them for animal and human food
- Market in Asia