Artemia is freshwater or seawater species?
seawater
What is plankton?
the diverse collection of organisms that live in large bodies of water and are unable to swim against a current.
Artemia can produce eggs asexually?
No. It reproduce sexually.
Why hatchery has to culture microalgae?
food source for zooplankton, bivalve, gastropod, fish larvae, shrimp larvae
What is the species name?
Brachionus plicatilis
Give TWO (2) differences between moina and daphnia
Moina is smaller in size, higher protein content.
Give THREE (3) factors to be considered while selecting types of feed.
the species being cultured, age of the animals being fed, culture conditions, level of intensification.
Why Daphnia is not suitable for marine fish species?
Freshwater species, Low content of essential fatty acids, Low HUFA
When fish larvae starts to eat? How many days old?
3 or 4-day-old
Give THREE (3) characteristics of fish fries.
Delicate and small, Power of movement + ability to feed - weak, Their diet is restricted to a number of items, Very low adaptive to environment.
What are live foods?
Able to swim in water column, Constantly available to fish and shellfish larvae, Likely to stimulate larval feeding response.
Give THREE (3) reasons why rotifer is so popular among fish hatcheries?
Tolerance to a wide range of environmental conditions, High reproduction rate, Small size, Slow swimming velocity.
Microalgae reproduce asexual or sexual?
Asexual and sexual
Daphnia can reproduce asexual and sexual?
Asexual and sexual
Give TWO (2) benefits of using live feed.
suitable for larval stages of marine species that will not accept artificial feeds • the nutritional value can be manipulated to meet requirements.
Give TWO (2) disadvantages of live feed.
• unreliable quality and quantity when obtained from the wild • labour costs • specialist skills required for culturing • culture continuously
Copepod produce eggs asexually.
No. Sexually.
Why fish hatchery needs live feed?
Larval rearing success largely depends on fish larvae feeding
Give TWO (2) reasons why fish larvae won't eat pellet?
Small size (small mouth size), Uncompleted development of their perception organs (eyes, chemo receptors), Digestive systems. Cant produce enzyme for digesting
When rotifer reproduce sexually?
when environmental conditions are stressful.