Week 3 - Meroplankton Flashcards
What are meroplankton?
Temporary members of plankton, including larvae of benthic species, eggs and larvae of nekton, and cnidarian eggs and planula larvae.
What is the nauplii stage in barnacles?
The nauplii feed in the water column.
What is the cyprid stage in barnacles?
A non-feeding stage that settles back on to substrate.
What is the medusa stage of jellyfish?
The sexually reproductive stage that is free-swimming and bell-shaped.
How do male medusae reproduce?
They release sperm into the water, fertilizing eggs produced by female medusae.
What is the planula stage?
A free-swimming, ciliated larva that develops from a fertilized egg.
What happens when a planula settles?
It attaches to a hard surface and transforms into a polyp.
What is a scyphistoma?
The settled polyp stage of jellyfish, which is sessile and cylindrical.
What is strobilation?
The process where a scyphistoma forms a series of disc-like segments that develop into juvenile medusa.
What are ephyrae?
Juvenile medusae that break off from the strobila and become free-swimming.
What nutritional mode do lecithotrophic larvae exhibit?
They are non-feeding larvae that possess yolk reserves.
What is planktotrophic larval mode?
Feeding larvae that possess well-developed feeding and swimming organs.
How are downstream larvae characterized?
Their mouth is located behind the ciliary band, allowing them to feed as they swim.
What characterizes upstream larvae?
Their mouth is anterior to the main locomotory ciliary bands, making food capture indirect.
Define teleplanic larvae.
Planktonic for over 2 months, possibly up to 1 year.
Define actaeplanic larvae.
Coastal planktonic for 1 week to less than 2 months.
Define anchiplanic larvae.
Planktonic for a few hours to a few days.
What are the rewards of planktonic larvae?
- Increased gene flow
- Dispersal of population
- Reduced predation from adults
- Reduced competition for space
What risks do planktonic larvae face?
- High mortality during critical release and return phases
- Predation in the water column
- Transport away from suitable sites
True or False: Longer Planktonic Larval Duration (PLD) generally leads to greater dispersal distances.
True
What is the role of planktonic larvae in benthic recruitment?
They contribute to the replenishment of local populations and help establish new colonies.
What factors influence larval dispersal distances?
- Current strength
- Larval duration
- Species-specific traits
What is the importance of self-recruitment in larval populations?
Some larvae return to their natal site due to local hydrodynamics or active behavior.
What is the significance of settlement cues for larvae?
Larvae detect environmental signals to locate suitable habitats for settlement.
