Larvae Flashcards
What is the gold standard of larvae feed?
and why are rotifers convenient?
copepods
Lots of research done on rotifers and the size is small enough for larvae with their small mouth (after yolk has been absorbed) to be eaten
What is crucial for larvae feed?
the right lipid profile
•Considering their biology, what do you think would be critical factors affecting larval rearing in aquaculture?
Bottlenecks
new species (broodstock from the wild), larvae survival is the biggest bottleneck
What are some characteristics of fish larvae?
Often transluscent, lacking pigment
Eyes often not fully pigmented
Lack developed fins (fin fold) and ossified (lacks calcium-> soft) skeleton
Different erythrocytes (red blood cells)
Often lack acid stomach, skin, scales and gills (diffusion) -> very fragile
Often lack Different muscle structure – anguilliform swimming mode
why do larvae not see well?
Larvae have cones that can see colour early on Rods that are sensitive to light intensity develop later
Short focal length
Acuity increases with age
Study: field of vision change within four days
Why is light regime critical for larval success?
Must consider Light spectra, intensity, photoperiod often habitat linked
Must adjust light according to development of larvae
Light requirements may vary across lifecycle, eg planktonic v benthic
-> can’t eat if they can’t see
Study: looking at optimal light intensity
What is most important for successfully rearing larvae (e.g. striped trumpeter)?
Feeding and growth are improved in black tanks with greenwater and enriched prey
What is critical informatino for aquaculture regarding larval development?
- What is light quality in the tank?
- Can larvae see prey?
- What is the nutritional quality of the information?
- What is nutritional requirement of larvae?
- Where in the tank are the larvae?
- Where should larvae be in tank?
- How do these requirements change during ontogeny?
