ABSTRACT
Whatever the species being reared the basic form of an aquaculture unit is similar in principle: obtaining mature broodstock and inducing spawning have already been described. The fertilization of eggs, their incubation, the rearing of the fragile, tiny animals which hatch from the eggs are processes which usually take place in the same structure, the hatchery or in some cases combined hatchery and nursery. The characteristic stages of development can be demonstrated by the techniques used in the rearing of carp; hatched larvae are transferred to cylindro-conical vessels such as Zoug jars of around 300–500 litres capacity, supplied with water through the base for three days at 20–24°C. No food is supplied. The hatchery is central to the problems and the prospects of the 'new' aquaculture. For fish, the hatchery and nursery are associated. This chapter concerns fish; however, the production of algae and zooplankton is also necessary for other groups.
