Twin-tailed Goldfish

Twin-tailed Goldfish
These goldfishes are termed "twintails" because their causal and anal fins hang in double folds. Their aquarium-bred bodies become truncated and egg-shaped, and the ability to swim is gradually impaired as the form changes from the natural streamlined shape. These restrictions mean that twintails are not suited to outdoor ponds. They could not compete in a race for food, nor flee from predators. Their delicate fins may also become congested in inferior water conditions. The maximum size of a twin-tailed goldfish attains depends on the size of the tank in which it is kept.