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Genetic resources are the foundation on which
species, stocks and genetically-improved strains
are based. At the species level, more aquatic
animals are being farmed now than ever before.
Although the common carp, Cyprinus carpio
and goldfish, Carasius auratus, were
domesticated several thousand years ago into a
variety of shapes and colours, most of the farmed
fish today are very similar to their wild
relatives. Improvements in our knowledge of
artificial reproduction, reproductive biology,
early larval rearing (training series) and basic
genetics have recently allowed fish breeders to
improve genetically species such as rainbow trout,
coho and Atlantic salmon, channel catfish, Nile
tilapia, as well as common carp.
The culture of several important species still
relies on the collection of brood stock or seed
from natural populations. Perhaps the most
important group of species whose culture is
dependent on natural populations is the marine
shrimp Penaeus spp. Shrimp farming in South and
Central America stock production ponds with
wild-caught larvae. Hatcheries that produce shrimp
larvae exist in Asia and the Americas, but the
broodstock are generally collected from the wild.
Culturists recognize the problems associated with
this harvest of wild resources and are taking steps
to domesticate marine shrimp. Other culture systems
dependent on wild resources include milkfish in the
Philippines, yellow tail in Japan, and eel in Asia
and Europe.
However, simply having a domesticated species or
genetically improved species is not sufficient to
guarantee optimum production from an aquaculture
facility. In addition to proper husbandry, i.e.
water quality, nutrition, health etc., broodstock
must be managed to ensure conservation of genetic
resources, to maintain the desirable characters of
the farmed species and to avoid problems of
inbreeding.
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