What is broodstock selection?

What is broodstock selection?

Broodstock selected for induced spawning must weigh at least 1.75 kg for females and 1.5 kg for males. Broodstock are generally discarded when they reach 10 kg or when the relative productivity (number of viable eggs produced) is less than 5 % of the female weight.

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 broodstock in fish farming?

In fish farming, broodstock signifies a group of sexually mature female and male fish, kept separate for breeding purposes. The advantage of maintaining a broodstock is that eggs and fry can be produced in a controlled environment, with no reliance on wild populations.

What is broodstock holding?

Broodstock can be a population of animals maintained in captivity as a source of replacement for, or enhancement of, seed and fry numbers. These are generally kept in ponds or tanks in which environmental conditions such as photoperiod, temperature and pH are controlled.

How do you identify a spent fish?

Spent phase: The ovaries are flaccid, shrunk and sac-like reduced in volume and have a dull colour. The vascular supply is reduced. Some unspawned large ova and a large number of small ova are present.

What is a broodstock salmon?

Broodstock is a group of sexually mature adult fish that are bred together in a hatchery or aquaculture facility. Segregated broodstock hatchery programs use hatchery salmon and steelhead (identified by their clipped adipose fin) each year as broodstock for the next generation of hatchery fish.

Why is managing of genetic aspect important in broodstock management?

The most important of these relate to broodstock management. Therefore, managing genetics aspects is critical to ensuring the long term integrity and viability of a breeding program, and has important implications to the genetic integrity of receiving populations.

Why do fish spawn over time?

Oxygen levels of the water, availability of food, size of each fish, age, number of times the fish has spawned before and water temperature are all factors known to effect when and how many eggs each carp will spawn at any one time.

What is breeding of fish?

Fish reproduce by bearing live young or by laying eggs. Livebearers give birth to fully formed and functional young called fry. The eggs are fertilized and hatch within the female. Most species of livebearers kept in home aquariums are generally easy to breed. Identifying sexes is usually easy as well.

How do you determine fish fecundity?

The fecundity is then F = nV/v where n = number of eggs in the subsample, V = volume to which the total number of eggs is made up and v = volume of the subsample. In practice, it is normally necessary to count more than one subsample from each fish to get a reliable estimate of the fecundity.

How can feeding responses be used to select broodstock?

Use of feeding responses during an initial period of isolation can be used by hatchery operators and farmers to select broodstock individuals that produce higher quality and quantity of tilapia seed.

How do you breed broody fish?

In most cases broodstock selected from nature or bought at a fish farm are kept in earthen ponds at a stocking density of 0.5-1/m2 and fed regularly with agricultural waste products and sometimes with some trash fish. Egg development will take place and about six weeks after a female has been reproduced it can be used again.

Are fingerlings from LSR broodstock better than those from HSR broodstock?

The results suggests that fingerlings derived from LSR broodstock pose an advantage over those produced from HSR broodstock in overall production performance. This would likely be further amplified were fish growout extended to 4 or 5 months.