Fish Health - Gill Disease
I could fill this site with
what's called gill disease.
Gill disease is down to the fishes
condition. we are back to water quality again. As with any infection first
think water water water and test test test.
Do a pH test twice. If
you're happy with this, then do a gill scrape. This why I'm on call 24 hour in
summer months, and now with the changes in the climate, through the winter as
Combined with the Israel fluke, the cool water fluke in this
country now ensures gill problems are not restricted to the warmer months.
Gill scrapes have to be done because a fish at the surface can have
problems ranging from a wasp sting to branchiomyes, dactylogyrus and other
First you must identify the cause before any action
is taken. You need to do what's called a gill snip. This is done by first
lifting the gill cover (known as the operculum) using fine (sharp) scissors.
The best type is iris tenotomy scissors. Snip a small amount of the gill
lamellae (not too small a piece) from the top of the operculum - either end it
doesn't matter - place the snip on a slide with 2/3 drops of saline (6gm pure
salt-100mil pure water).
Using your microscope, look for big targets
(low magnification 10 times objective). Look for gill fluke and white spot.
Gill damage can also be caused by contaminated food (old or damp)
entering the blood stream, which in turn reaches the gills.
pollutants/ garden chemicals damage the make up of the gill epithellium. This
causes the epithelial sheets to lift from the blood vessels, also causing
accumulation of fluids.
Lamellar fusion occurs when several or more
secondary lamellae fuse together.
Hypertrophy when cells individual
ones get to large hyperplasia - uncontrolled cell growth - the epithelium
becomes mass of cells, not a thin sheet, so the exchange is much reduced.
Blood supply to the gills can get damaged when fish is exposed to poor
water conditions. Blood vessels can burst leading to lamellae aneurysm - the
secondary lamellae swell up with escaping blood. Blood vessels get congested
with blood cellular products, reducing blood supply from the gills, thus
cutting oxygen supply to the tissues of the fish
Note: when you
turn away to look up what you have found remember to turn miroscope light off
to keep specimen alive. Only have light on when your looking down the scope.
If none of the above is found now comes the hard work. Come a way from
the scope and do a check list:
Have you done all your water tests?
Is there any thing you may have missed?
When did the last new fish go
in the pond?
Has one of your neighbours been spraying?
Are you under a
flight path where aircraft dump fuel?
Have you introduced new fittings or
changed the pump recently?
Have any friends been round helped you with
netting a fish using their nets?
Have you used a watering can that is not
your normal one?
If none of the above give you a clue, then contact
me without delay. Don't email, phone my mobile 07889 540 083 because time
now is our biggest problem - I don't carry a magic wand - once the fish stress
levels rise then secondary problems start to show themselves. What was a minor
problem can become a fish killer.