The Sterile System
47
those which inhabit coral reefs, may only survive in captivity in
sterile systems. The reason for this is that the typical reef conditions
—high turbulence and strong currents—probably maintain a very pure
local
environment
which
can
only be simulated by the sterile
systems. For these fishes, all the time and trouble involved in
setting up the system will be worth While.
Finally, it is a good rule, when buying exp-ensive specimens,
to find out— whether they have been kept in a sterile environment,
and if so to consider their chances of survival in a non-sterile system.