Tuna reproduction cycle Flashcards
When do tuna migrate to spawning grounds?
typically during the warm summer months
What happens during broadcast spawning?
females release eggs while males selease the sperm into the water
What is broadcas spawning?
where eggs and sperm are released into the ocean and fertilization occurs externally
What is the problem with broadcast spawning?
it isn’t very successful and so many eggs are released
How many eggs can a 5 year old tuna release?
5 million
How many eggs can a 20 year old tuna release?
45 million
What is the benefit of broadcast spawning?
There is significant genetic variation from the various sperm gametes in the water
What do fertilised eggs do?
eggs are buoyant (from oils) and float near the surface in the planktonic waters
How will many eggs be lost by?
predation
When will eggs hatch?
2-4 days
Where do tuna larvae live?
planktonic waters
What do tuna larvae feed on?
larvae of other species (zooplankton)
What do tuna larvae have to help them feed?
big heads and jaws
What happens to larvae tuna after about 6 months?
They are big enough to swim into the open ocean
Why do juvenile school?
to help avoid predation
