Basics
What are microalgae?
Microalgae are microscopic, photosynthetic organisms
What daily task should be done to maintain healthy algalcultures?
SWIRL
What feature makes Tetraselmis chuii easier for larvae to capture than some other algae?
It is motile, meaning it can swim and remain suspended in the water column.
What is F/2 media?
Nutrients
Why are darker, more established cultures used to inoculate new carboys instead of very light cultures?
Darker cultures have higher algal density and are more likely to establish successfully.
Why are microalgae important in aquatic ecosystems?
They form the base of aquatic food webs and support higher trophic levels.
Which shellfish life stage depends most heavily on microalgae, and why?
The larval stage, because larvae cannot capture large food and rely on microscopic, nutritious particles.
Why is Isochrysis galbana considered especially valuable for early larval stages?
It is rich in DHA, an essential fatty acid important for early development.
What are two advantages of using a mixed-algae feeding strategy in hatcheries?
Improved nutrition, higher larval survival, faster growth, and greater resilience.
What are 4 things that you need to start an algalculture?
Light, air, clean carboy, airline tubing, filtered saltwater, starter sample, nutrients, airstone
How do microalgae contribute to Earth’s oxygen supply?
Through photosynthesis, microalgae produce a large portion (about half) of Earth’s oxygen.
What two measurements are commonly used to evaluate larval success in hatcheries?
Survival rate and growth (such as shell length).
What nutritional benefit makes Nannochloropsis oculata useful in aquaculture systems?
It is high in omega-3 fatty acids and is commonly used to feed rotifers and support larval nutrition.
Why must sodium thiosulfate be added before adding algae?
It neutralizes chlorine so it does not kill the algae
What are two challenges hatcheries face when culturing multiple microalgae species?
Increased cost, labor, time, and risk of contamination.
In which zone of the ocean does most microalgae photosynthesis occur?
The photic zone, because enough sunlight penetrates this zone to allow photosynthesis.
What is an algae crash, and how can it affect larval survival and water quality?
An algae crash is a sudden die-off of cultured algae that can cause food shortages, poor water quality, and increased larval mortality.
How does Chaetoceros muelleri support shell development in bivalve larvae?
As a diatom, it contains silica and provides nutrients that support shell formation.
Why might a diet containing three algae species outperform a diet with only one or two species?
Multiple species provide a wider range of nutrients and reduce the risk of nutritional deficiencies.
What might cause an algalculture to crash? Give 2 reasons
Contamination, overcrowding, lack of space, light & nutrients