It is a cumulative process of improvement and, as such, is a long-term activity which has been very successful for aquaculture species. Genetic improvement is the cornerstone to domestication as it gives the potential to shape an organism to meet human needs. Perhaps the most important aspect of broodstock management, after spawning of the required quality and quantity has been achieved, is genetic improvement, the domestication process by which genetic selection improves desired traits over generations. Management points are those related to the logistics of egg and juvenile production or how aspects of the control of reproduction can be managed to improve production or provide particular characterises in the progeny that are needed for production. Critical points or limiting factors are those that need to be considered when setting up and managing broodstock to obtain adequate egg quality and quantity for commercial hatchery production. This chapter aims to describe broodstock management, the principles of control of reproduction and genetic improvement applied to finfish species, with emphasis on the principal aquaculture species in Europe.Ĭontrol of reproduction ( Section 2.2) has been classified into critical points and management points. Once protocols to achieve adequate spawning have been established, aspects of reproduction and genetic traits of the broodstock or population need to be managed to ensure the progeny have improved characteristics for ongrowing and the market. Chavanne, in Advances in Aquaculture Hatchery Technology, 2013 2.1 Introductionīroodstock management requires that biological (particularly reproductive) characteristics are understood and used to create a culture environment to enable the organism to reach advanced stages of maturation, vitellogenesis and spermiation from which the spawning can be obtained with adequate egg quality and quantity for commercial hatchery production. A more comprehensive discussion of puberty in cultured fishes is provided by Taranger et al. This discussion will primarily focus on the control of puberty for broodstock production.
Conversely, precocious puberty is common during production of many cultured species (e.g., Atlantic cod, Atlantic salmon, European sea bass) and can impact the growth rates and flesh quality of fish being grown for market. Delayed puberty is of great concern for broodstock of many aquacultured species, such as tunas, groupers and sturgeons, which require many years to attain reproductive maturity. Therefore, the ability to accurately monitor maturation is essential for efficient gamete production and utilization of hatchery resources. Goetz, in Fish Physiology, 2020 3.1 Implications and applications for aquacultureīroodstock require considerable hatchery space and costs to maintain, and minimizing the prepubescent period and number of reproductively inferior fish can have significant economic advantages.
This is an area that needs much scientific input to ensure genetic diversity is maintained.ĭavid L. The replacement and procurement of fresh broodstock are currently done on an ad hoc basis and based entirely on the farmers’ experience/intuition. Hatcheries normally recruit new broodstock on a regular basis of every two to three years new broodstock are obtained both from grow-out farms and the wild. 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. Broodstock selected for induced spawning must weigh at least 1.75 kg for females and 1.5 kg for males. Males and females can be maintained at the ratio of three to four females to six to seven males, either separately or together. The best stocking density is considered to be 4–5 t/ha. The age of fish at breeding should be over three years (normally five to six years).īroodstock are stocked at a rate of 5 t/ha (varying from 4 to 6 t/ha). (2010) reported that male and female broodstock (including potential broodstock) should be from 0.5–8 kg and 0.5–12 kg in weight (average 3–6 kg), respectively. (2010) reported in detail on broodstock procurement and concluded that broodstock could be sourced from extensive grow-out, export-orientated grow-out, capture fisheries, own hatcheries or other hatcheries, in that order of importance. There is a clear trend towards in the increased use of pond reared broodstock. Le and Le (2010) found that 78.1 % of hatcheries were using domesticated brood- stock (collected from grow-out ponds), 6.3 % using wild-collected broodstock and 15.6 % using both sources. De Silva, in Advances in Aquaculture Hatchery Technology, 2013 16.2.2 Broodstock sourcingīroodstock sources include pond (domesticated) and wild collected.