Guidelines For Collecting And Shipping Diseased Fish

Fish kills can occur at any time, but they are most common during the warmer months of the year. Fish kills can be caused by handling stress, poor water quality, toxins, or infectious agents such as viruses, bacteria, fungi, and parasites.

 

Identifying The Problem

First, determine if the cause is an infectious disease.

Some fish kills are due to water quality issues such as:

  • low dissolved oxygen.
  • ammonia poisoning.
  • nitrite poisoning (“brown blood”).
  • pesticides or other toxins

Try to eliminate these causes first by checking water quality on site while the fish kill is in progress. Water chemistry changes rapidly, so shipping water samples for this purpose is discouraged. If you not have the capability to do basic water quality testing, contact an Extension agent for assistance.

 

In Alabama, call:

Claude Reeves (334) 693-9065
Dave Cline (334) 844-2874

 

In west Alabama:

Bill Hemstreet (800) 423-5956  or  (205)  624-4016

In Alabama, call the Alabama Pesticide Residue Laboratory at (334) 844-4507 if pesticides are suspected. In other states, contact your state Department of Agriculture regarding sample collection for pesticides and other toxicants.

Next, observe the behavior of the fish. Are the fish:

  • not feeding?
    • lying lazily in shallow water or at the surface?
    • not swimming off  rapidly when disturbed?
  • gasping for air at the surface of the water?
  • swimming erratically?
  • floating (still alive) on surface?

These types of behavior are not exclusively clinical signs of disease, but if you have eliminated water quality problems and still observe some of these signs, then it is more likely that the prob­lem is an infectious disease.

Early detection and diagnosis of infectious diseases is very important if treatment is to be ef­fective. Do not guess at what is causing the prob­lem. Get a representative fish sample to a fish disease specialist for an accurate diagnosis. Remember, an incorrect diagnosis can result in a costly and ineffective treat­ment and a loss of valuable time, and it can further stress or even kill your fish.

 

Selecting Fish for Diagnosis

The most valuable samples for diagnosis are fish collected while alive and displaying signs of disease. Signs of disease include:

  • eroded areas on gills, fins, mouth, or skin.
  • open sores.
  • heavy mucus (slime) on skin or gills.
  • pale or swollen gills.
  • protruding or sunken eyes.
  • swollen or sunken bellies.

If you observe any of these signs, a diagnosis should be made as soon as possible.

When freshly dead fish that still have normal color, mucus, clear eyes (not cloudy), and red/pink gills can be used for diagnosis, but dying (moribund) fish collected while still alive are best. Do not send dead fish which have lost body and gill color. They are generally unsuitable for diagnosis, and you will be wasting both time and money.

Do not collect the sample fish by hook and line. Fish that are feeding well are usually not diseased. Try to catch the fish using a dip net. Healthy fish are generally too quick to be caught this way. If you must use a seine, select fish that show obvious signs of disease. Collect one or more fish for submission to the lab.

Transporting Fish For Diagnosis

Correct diagnosis depends on proper collection and transportation. Specimens must be transported quickly and under conditions which will preserve both the fish and the disease organism. If you are close to a diagnostic laboratory, you may wish to deliver the fish yourself. Please call the laboratory before transporting fish to discuss the details about your case and so that lab personnel will anticipate the arrival of your samples.

If the fish are to be shipped overnight to the diagnostic laboratory, use the following procedure:

Place the fish without water in a strong plastic bag. If fish are small enough, zipper type freezer bags work nicely.  Do not attempt to ship fish alive. They will die during shipping and will arrive in poor condition. Placing live (bagged) fish on ice will humanely euthanize fish. Freshly dead fish should be bagged individually without water and placed in a cooler on ice. Do not use dry ice as this will freeze the sample.

  1. Do not   place fish directly on ice without a plastic bag.
  2. Place the bagged fish in a plastic cooler (preferably) or heavy cardboard box lined with Styrofoam.
  3. Place cubed/crushed ice in separate sealed bags so as the ice melts it is contained and does not leak from the package. Using freezer bricks or frozen gel packs avoid s this problem. Pack enough ice packs around the fish to last at least 12 hours. Be sure to include contact information and fish disease history information along with your  samples.
  4. Seal the box securely and label it clearly.
  5. Ship the specimens by an overnight
    carrier.

If a fish-kill occurs over the weekend, samples can be frozen and shipped during working hours.

Do not preserve fish in alcohol or formalin for diagnosis unless there is no available refrigeration or unless this option has been discussed previously with lab personnel. Preserving fish in this manner kills parasites and microorganisms, thus making their detection more difficult.

 

Information To Include With Fish Samples

1. Your name.

  1. Your mailing address.
  2. Your telephone number.
    1. The size of your pond (in acres) or the volume
      of your tank or raceway.
    2. The average depth of the pond (or maximum
      depth).
    3. The date and time when the fish started dying.
    4. The number of dead fish and the loss per day.
      1. The number of fish stocked in the pond before
        the losses.
      2. The average size of the fish affected.
  1. Recent feeding rates.
    1. A description of any lesions, abnormal behavior or other signs of disease.
    2. A description of any treatments already applied.

Send this information with the specimens. Pack it carefully so it will not get wet. A sample Diseased Fish Information form is included at the end of this publication. Photocopy and complete the form, and include it with your samples.

Remember, do not send or bring in fish which:

  • are feeding aggressively.
  • have been taken randomly from a seine.
  • do not show signs of disease.
    • have been dead long enough to lose skin and
      gill color.

The Southeastern Cooperative Fish Disease Laboratory will diagnose fish diseases for the pond owner for a nominal fee. This service is available to the public during working hours; Monday through Friday.  Please call ahead if possible to discuss your case with lab personnel prior to submitting any samples.

Lab phone : (334) 844-9220

Send your samples to:

Fish Disease Laboratory
Swingle Hall
Auburn UniversityAuburn, AL 36849-5419

Or, if you live in the Greensboro area, send them to:
Alabama Fish Farming Center,
529 Centreville Street,
Greensboro, AL 36744

(800) 838-2332 or (334) 624-4016

Other overnight carriers may deliver fish samples, but check first.

Bacterial tests usually take two to three days. The pond owner will be notified of the results as soon as possible, and treatments will be prescribed.

203 Swingle Hall | Auburn, Alabama 36849 | (334) 844-4786 |
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