Brood-stock

Figure 45 Survival of eggs (A) and larvae (B) of pink salmon in relation to the concentration of docosohexaenoic acid in the triacyl-glycerols of white muscle of female brood stock. (Yuneva et al., 1990.)...

In species that do not readily become reproductive in captivity, sexually mature animals, specifically egg-carrying females, are often captured from the wild, as in the case with the penaeid shrimps that form the bulk of farmed crustaceans. Most brood-stocks of shrimps are still obtained from catches by means of trawl fishing (Wickins and Lee 2002), a method that is highly stressful and may result in crushing of animals. Additional stress may be imposed by transporting the selected brood-stock animals and introducing them into a new and confined environment. The whole process of capture, transportation, and introduction could lead to ovary resorption in females. Thus, a low-stress capture technique would certainly be valuable in this case. 

Possible solutions - Can knowledge of chemical communication help in designing less stressful methods for catching suitable brood-stock animals The straightforward solution should be based on a pheromone trap to which the required animals would be attracted and which they would enter voluntarily. However, the effective range of pheromones is usually unknown. 

Possible solutions - Harvesting has much in common with brood-stock acquisition, in that it deals with concentrating and capturing sexually mature, i.e., marketable animals. In fact, the brood-stock is often sorted out from the harvested animals to start a new culture cycle. Attractive chemical cues, such as sex pheromones involved in chemical communication between adult crustaceans, might be integrated into the aforementioned harvesting techniques, to increase the efficiency and rapidity of animal capture and to reduce the stress and loss of animals associated with this action. For example, such chemical cues might be released from traps or the collection basin. 

Brood-stock Acquisition of sexually active animals Reproduction Sex pheromone traps... 

BELL J G, FARNDALE B M, BRUCE M p, NAVAS J and CARILLO M (1997) Effects of brood-stock dietary lipid on fatty acid compositions of eggs from sea bass (Dicentrarchus... 

TAVE D (1999) Inbreeding and brood stock management. Fisheries Technical Paper No 392. Rome FAO. 

TAKEUCHi Y, YOSHizAKi G and TAKEUCHi T (2004) Biotechnology surrogate brood-stock produces saknonids. Nature, 430, 629-630. 

A wide range of conditions have been used to maintain the octopus brood-stock in captivity (Table 12.1). The method of capture, transport conditions, food supply and light intensity are similar among different research groups, but the most obvious differences are the male female ratios and the broad range of temperatures used (14-25 °C). 

Fig. 15.1 The 14 ha broodstock cove, barrier-netted from the ocean for PBT brood-stock at Amami Station, NCSE, FRA, Japan (Masnma et al, 2011). Reprinted with...

The first land-based system for Atlantic bluefin has recently been constructed in Cadiz, Spain by private company Futuna Blue. This is the largest bluefin facility in the world, with a floor space of 30000 m and two brood-stock tanks each of 4000 m. Like that previously described for Clean Seas Tuna, these tanks operate under sophisticated recirculating systems capable of completely controlling all aspects of the environment (Urup pers. com.). 

---