The Gill maggot lays twin egg
sacs (around 1.5mm).
It is only the female that attacks fish, the male
stays in the plankton swarm.
It is mainly a gill infection, but I have
seen ergasilus on skin and fins.
The best way to describe this
infection is that it looks like half-dead anchor worm. In fact, in the gills,
that's just what it looks like.
The symptoms are very similar to gill
Infection is transported between sexually mature
adults on fish (quarantine). Also by adding native fish to a pond, from a bag
of water and net used at side of a bank (mainly lake). Also the nauplii can be
transported in bags of live food.
You would be surprised how many fish
keepers buy these little bags of live food to add to their ponds. No wonder
garden centres can get away with selling tonic salt.
It can also be
carried via birds bathing in a waterfall where your pond is near a fishing
Ergasilus responds very poorly to treatments. In fact I fine it
very hard to treat, as death is mainly by ergasilus digesting the epithelial
cells in the gills, and allowing secondary infections to develop such as
columnaris, or fungus. Treatment of either of these will have no affect on
ergasilus and you cannot treat one without the
I have now found a treatment and tests are