Admin Table of Contents
- 1 How would you select a good quality broodstock?
- 2 What are the several indicators of ripeness in fish?
- 3 What is meant by the term brood stock?
- 4 Why we have to feed the broodstock with highly nutritional diet?
- 5 How do you get seeds from fish?
- 6 What is a larval oyster?
- 7 What happens when you spawn on peaceful difficulty?
- 8 How much experience does a spawner drop in Minecraft?
How would you select a good quality broodstock?
BROODSTOCK MANAGEMENT (a) The selection of fish with desirable hereditary qualities typical of improved strains such as rapid growth potential, higher resistance to dissolved oxygen deficiency and adverse water quality, strong appetite, omnivorous feeding regime.
What is the importance of maintaining broodstock in good condition?
Broodstock managers can use or select for traits such as fast growth rates or disease resistance over generations to produce more desirable fish. This ability for genetic improvement of stocks is more efficient and produces higher value stock. Broodstocks also enable you to selectively plan and control all matings.
What are the several indicators of ripeness in fish?
In most species, ripeness reflects enlarged gonads and a «loosened” follicular structure. This results in the characteristics most commonly used for selecting ripe female fish: large, soft abdomen and a swollen gonadal papilla.
What is the importance of proper broodstock management to aquaculture?
It is important to manage broodstock nutrition and pre-spawning conditioning, spawning and the immediate post-hatch stages (egg incubation, larviculture and post-larval husbandry). Broodstock nutrition and husbandry practices can affect gamete quality which, in turn, affect seedstock quality.
What is meant by the term brood stock?
Definition of brood stock : a small population of any animal maintained as a source of population replacement or for the establishment of new populations (as of game birds) in suitable habitats.
What is broodstock conditioning?
Conditioning broodstock is essential in the provision of larvae for culture (Figure 32). It is the procedure by which hatcheries are able to extend their production season, removing reliance on the relatively brief period in the year when adults of the desired species are bearing mature gametes in the sea.
Why we have to feed the broodstock with highly nutritional diet?
An improvement in broodstock nutrition and feeding has been shown to greatly improve not only egg and sperm quality but also seed production. Gonadal development and fecundity are affected by certain essential dietary nutrients, especially in continuous spawners with short vitellogenic periods.
What are the three factors that triggers fish maturation and spawning?
Both photoperiod and temperature are considered important factors controlling the maturation of gonads in fishes (Hazard and Eddy, 1951). Variations in the duration of light and/or temperature, may influence the rate of gonadal development. Bullough (1940) has reported the existence of an internal rhythm in Phoxinus.
How do you get seeds from fish?
Fish seed production includes egg to spawn production for 3 days, spawn to fry nursing for 15-20 days, fry to fingerling rearing for 60-90 days and fingerling to yearling rearing for 8-9 months.
How big is the holding tank in a fish hatchery?
The most common design being rectangular earthen ponds or round concrete tanks between 50 and 200 m3, but which can go up to 500 m3. This capacity is sufficient to hold a good number of fish, but at the same time allows an easy visual control of the captive broodstock and a proper water flow.
What is a larval oyster?
Once oyster larvae attach to a surface, such as other oyster shells, they are known as spat (shown in inset image). As generation after generation of spat grow into adult oysters, they form dense clusters known as oyster reefs or beds. Once the larvae permanently attach to a surface, they are known as spat.
What are strongstrong indicators?
Strong indicators can be quantitative or qualitative, and are part of the evaluation plan. In evaluation, the indicators should be reviewed and used for program improvement throughout the program’s life cycle. Indicators can relate to any part of the program and its logic model or program description.
What happens when you spawn on peaceful difficulty?
In Peaceful difficulty, spawners still appear and work, but any spawned hostile mobs disappear immediately after spawning. Zombified piglins, magma cubes, and ghasts do not spawn at all.
How much experience do spawners drop with silk touch?
Spawners cannot be obtained in Survival, even with Silk Touch . If broken with a pickaxe, a spawner drops 15-43 experience. When mined with anything else, they drop nothing.
How much experience does a spawner drop in Minecraft?
A / setblock, / clone or / fill command can also be used to obtain a spawner. If broken with a pickaxe, a spawner drops 15-43 experience. When mined with anything else, it drops nothing. ↑ Times are for unenchanted tools as wielded by players with no status effects, measured in seconds.