Ammonia burns are the most common reason that goldfish turn black. High ammonia content in fish tanks causes irritation and trauma to the goldfish's fins. Ammonia burns are white in color and turn black as the goldfish heals.Know More
Additional reasons for a goldfish to turn black include ingestion of colored fish flakes and genetics. Many goldfish possess a random mix of color genes, which in turn can lead to color variations.
High ammonia levels in a fish tank are easily remedied with a 25 to 50 percent water change. Ammonia levels tend to fluctuate when there is undigested food or fish droppings in the water as these items emit excess ammonia while decomposing.Learn more in Aquatic Pets
There are breeds of goldfish that are characterized by bulging eyes. However, for other breeds, if the eyes on a goldfish are protruding, it may be that the fish has an infection, is physically injured or has a metabolic disorder or that the eyes are responding to poor water conditions.Full Answer >
Swim bladder disorder is the most common reason for a betta fish to float on its side. There are numerous causes of swim bladder disorder, including disease, physical trauma, parasites, environmental factors and constipation.Full Answer >
According to Encyclopaedia Britannica, the goldfish, a member of the carp family that originated from ponds in East Asia, is an egg-laying fish. A fish that lays eggs cannot be pregnant, and therefore no special designation exists for a pregnant goldfish.Full Answer >
Reasons why a goldfish is gulping air include poor water quality, overcrowding of the tank and oxygen deprivation. Goldfish require consistent cleaning and filtration of the water in order to keep the fish healthy. If too many fish are in the same tank, it can lead to bad water quality and not enough oxygen for the fish, causing the goldfish to gulp air at the surface of the tank.Full Answer >