Dead Blue Tilapia & Goldfish

[Bob Gee]

My system has been running for about 2 months now and over the last two weeks I have been losing tilapia and goldfish. I don't understand what is going wrong. Most of the dead tilapia shows signs by swimming without a sense of direction (i.e. swimming in spirals, running into objects, not moving or controlling position when still). Every now and then I go out and check the system several times and the tilapia were showing no signs; however the next visit will render one dead at the bottom. Pretty much all of the goldfish end up at the surface with little to no scales left. As with the tilapia most don't show any signs of a problem, if they do it would be lethargy and staying toward the bottom. Overall I am losing any where from 2-6 fish a day.Here are the numbers from today:

pH=7.5

Ammonia=.25ppm

Nitrite=0

Nitrate=0

The fish are young and the system is large (250gal fish tank and 5 1/3 IBC tote beds). I feed them homemade food and  duckweed. I have know idea what to do.

[Ray Absher]

My guess is a virus. Do the fish exhibit the following?

Spring Viremia of Carp (SVC) (viral)

-  lethargy and uncoordinated movement
-  bulging eyes, skin hemorrhages
-  bloated appearance due to fluids in the abdomen
-  bloody mucus trailing from vent and within the intestine

Goldfish are a form of Carp, not sure if Talapia may acquire the virus though.

Further info -

http://edis.ifas.ufl.edu/vm106
  
caused by the SVC virus usually at low temperatures (40-65 deg F)
Rhabdovirus carpio is the scientific name of the virus
this virus suppresses the immune system of the fish, making the fish vulnerable to secondary pathogenic invasions
easily spreads from fish to fish

SVC infections are of international concern so deaths from this disease must be reported accordingly
SVC has no known cure, but many experts believe that the chances of a fish surviving its attack is greatly increased by keeping under control all parasitic and bacterial infections that may occur concurrently with the SVC
studies have shown the SVC virus not being able to survive above 83 deg F, so experts recommend raising the water temperature to 86 deg F for 5-7 days before treating the sick koi
the water temperature may then be gradually decreased by a maximum of 2 deg F per day until it is down to 80 deg F, at which point treatment of the secondary infections of the koi may be initiated and sustained until all symptoms are eradicated

[Ray Absher]

Upon further research I found the following -

http://www.americulture.com/Disease.htm

Streptococcus has additional clinical signs including an erratic spiral swimming motion, a curved body, corneal opacity in one or more eyes, exopthalmia (protruding eyes), and abdominal distention.

[Robert Dietrich]

I'm guessing you live out in the estates as I do. I have had a similar problem with my goldfish. They were swimming around in a school near the top of the pond and then one day they were all at the bottom and the next day I started to find dead fish. This has continued for several days.

I have noticed that last week I got a big algae bloom in a pond I keep mosquito fish in and my big pond began to grow hair algae .  Have you had any trouble in this regard?  

I've also been wondering if the county is spraying for mosquitos again. I'm not sure that would effect the fish but they are small.

[Patrick McKee]

What does the homemade food consist of?

[Bob Gee]

spinach, lettuce, shrimp, rice, orange, paprika, and peas

Patrick McKee said:

What does the homemade food consist of?

[Patrick McKee]

Hi Bob,

Where do you get the ingredients; what are the ratios; how is it being fed to them; is it pellets; do you know the level of protein and vitamins they get from the food?