Clownfish typically weigh around 250 grams and are 4 to 6 inches long. Male clownfish are significantly smaller than females. A clownfish at birth is gender neutral, meaning it is neither male nor female.
Clownfish have the capability to change their gender. If a female clownfish dies or is removed from a tank, the most dominant male will change into a female. In a home aquarium, a young clownfish can make the change from juvenile to male, to female, in as little as one month. Clownfish feed mostly on tiny invertebrates and have a lifespan of five years.