How big is your tank? You realistically should take the comets back to the store-they grow to be 12-18inches in length very quickly and really belong in a pond environment. Ryunkins really should not be kept with comets. Comets are the faster, more aggressive (esp when it comes to feeding) species of fish and they will out compete the ryunkin for food. How are your water parameters (amm/nitrite/nitrate)? Unusual behavior and issues with their scales can be attributed to water quality issues.