Murray cod are entirely a freshwater species
and will not tolerate high salinity levels. They are also generally
quite hardy, however may be susceptible to bacterial and fungal
infections at high stocking densities. Therefore excellent water
quality must be maintained.
As a general rule, stocking densities in tanks should not exceed
80kg/m3 unless the farmer is confident that limitations of the
system will allow higher densities. Water should be clean, with
a relatively neutral pH between 6-8, dissolved oxygen above
3mg/L and free ammonia levels of less than 0.1mg/L. Temperatures
should be maintained at 24-25° C. Water sources for the
operation should be free of pesticides and other contaminants.
It should be noted that the above parameters are ideal levels,
although the Murray cod may tolerate conditions outside of this
range for short periods of time. Prolonged exposure to unsuitable
or undesirable conditions will stress the fish and leave them
open to attack from a number of parasites, fungal and bacterial
infections, and viruses. This may cause mortality, and infection
may spread to other tanks causing expensive losses. Even if
no infection occurs, growth rates may be inhibited. |
