Wednesday, 14 January 2015

Aquaponics UK - Trout Autopsy Part !

It has been cold and wet here. I have been feeding the Trout in the morning and again in the evening after work. Probably not waiting long enough to observe them.
So my fault I may not have picked up this problem as early as I should have.
However when I did I immediately moved him to a hospital tank.
The white tail was distinctive.
None of the other fish are displaying any symptoms.

 My hospital tank is a 70 litre  glass aquarium. It has its own filter/heating  system and is completely separated from the main system.
The trout was swimming and appeared to be feeding normally. The ‘nude’ tail was the only symptom. 
With hindsight he was netted very easily, swimming on the surface and transferred to the hospital tank. Transfer stress can also be a problem.

The water in this tank was drawn from the main system, so equal PH, temp etc.
However I had salted this water to 6PPT.
In commercial fisheries and when dealing with ornamental fish many different chemicals are used. However when dealing at home with fish for human consumption  salt is you main ally.
Salt has an OSMOTIC action on fish. It can best be remembered by the acronym’ SALT SUCKS” That means water, and the bad things, bacteria etc, move from the LESS saline area to the more saline area.

I am learning with fish health so Google is my main source of information.
White tail disease was my initial guess but further reading leaves me unsure. This seems to mainly affect Prawns.
My best guess now is Bacterial Cold Water Disease; With an additional fungal infection.   If you know better please comment.

So sadly he died.

I decided to dissect him. This would also give me a chance to use my new smart phone microscope. I built this from instruction on the internet. An additional lens is added to the existing smart phone camera to give a magnification up to 150 times.

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