"Shimmies" or "clamped fins" is not a disease in itself, but rather a sympton of disease or fish stress. Because it can have so many different causes like columnaris or the different forms of flukes, this entry in the Disease Library is meant to provide a general description of this condition.
Symptoms and Behavioral Signs
A guppy has clamped fins that it holds close to its body, and its caudal find is folded. It hangs near the surface, relatively immobile. It may shimmy or swim somewhat erratically.The following symptoms may selectively appear:
- Fins clamped
- Guppy shimmies
- Fish is shy or hiding
- Fish lack appetite
- Fish is still or inactive
These symptons can describe a variety of parasitic diseases that can only be properly identified with a microscope. The problem with treating shimmies or clamped fins without knowing the cause is that you may subject the guppies to chemical stress or adversely affect the water conditions.
Causative Condition
High ammonia, nitrite or nitrate levels in the tank. Low oxygen levels. High level of organic waste in the tank. pH levels out of range (less than 7.0 or more than 8.4) or a recent sudden change in the pH, temperature or hardness levels. If the problem is confined to one or several tanks, the chances are that the nitrogen cycle is out of whack in those selected tanks. This may be due to overfeeding or to a mechanical failure in the filtration system. If the symptons appear after a period of stability, and they appear in more than one tank, and there has been no recent introduction of new guppies to the community, you can probably assume that the guppies have been overfed.
Diagnosis
If the fish are scratching or flashing it is an indication of irritation of their skin, and could be due to external parasites. If the fish are swimming erratically, it is probably a parasitic disease. See library entries for Chilodonea, Costia, Skin Flukes (gyrodactylus), White Spot (Ich) and Velvet Disease
Examine the fish for any other signs of abnormalities or disease. If clamped fins are the only symptom, then it is probable water conditions are bad. If they are hanging near the surface, and there is not other signs of disease, than it is probably poor water quality.
Look on the bottom of the tank. Do you see a lot of mulm compared to other tanks? Is there uneaten food on the bottom? Is the water cloudy? Are the filters clogged? Is the filter water flow restricted? These are signs of overfeeding or the failure of the nitrogen cycle.