Oyster reproduction cycle Flashcards
What are oysters?
bivalves
How are oysters sessile?
They attached to substrate and unable to move as adults
What do oysters do with their gills?
oxygen and feeds
What AREN’T oysters?
hermaphrodites
What happens to oysters between their early and later years?
oysters are male in their early stage and later become female when big enough to devlop eggs
How do oysters spawn?
broadcast spawning
How is broadcast spawning triggered?
by temperature above 16 degrees celsius
What happens during broadcast spawning?
release of gametes triggered by pheromones
How many eggs do oysters spawn?
10 million eggs to help improve chance of success
How long does it take oyster eggs to hatch?
6-12 hours after fertilisation
Explain the trochophore (larval) stage
Free swimming in planktonic waters
use cilia to help move and disperse
How long is the trochophore stage?
5-10 hours
Explain the veliger stage
- Occurs within 24hrs of fertilisation
- Development of shell (vellum) for protection
- Still in planktonic waters
- Continue to grow for 1 week
Explain the pediveliger stage
- A foot develops for attachment to the substrate
- 1-2 weeks
- Starts in planktonic waters and sinks to benthic environment
- Find suitable substrate (attachment sites and mating options)
Eplain the spat stage
- Attaches to a substrate near other oysters
- Grows for 2-3 years into sexually mature adult
