Care
A cross between a single-coloured metallic koi (Ogon) and a standard domestic Common carp, Ghost koi get their name from the coloured highlights on an otherwise dark body. Their koi heritage brings either a gold or silver metallic sheen, which adds colour to a fish with rapid growth rate and vigour. 'Ghosties' have all the charisma of koi in a cheaper and hardier package, making them very popular with pond keepers. Like koi, they grow large and often show a faster growth rate thanks to their food fish ancestry, particularly those with reduced 'mirror carp' scalation.
There's no denying that their price puts them in more typical garden ponds than purebred koi but they're equally large and destructive fish, so bear this in mind before adding youngsters. To see them at their very best, keep them as you would koi - in big, deep, well-filtered ponds. To ensure healthy development and maximise water volume, a pond designed for carp should be at least 1.2m/4' deep but the bigger the better. These are pets that get better with age and tend to outgrow smaller facilities, this leads to serious owners often upgrading their ponds as their fishes mature. Large, greedy carp in big ponds need serious filtration and this is a factor to be considered at the planning stage, with helpful hardware such as bottom drains installed in the early stages of construction. The fact that many standard garden ponds have one or two swimming amongst goldfish and orfe is a tribute to how hardy they are, and they'll enjoy uprooting the plants and foraging in the mud in the same way their wild ancestors did. The fact that dedicated carp ponds tend to be bare is testament to the fact that they demolish most attempts at planting, so ensure any vegetation is out of reach and consider adding a 'plant filter' where the benefit of waste removal can be harnessed safe from the fishes. Unlike wildlife ponds, carp ponds are best filled using tap water to ensure healthy mineral content - keepers in soft water areas are advised to add buffers to increase KH levels and monitor these alongside the usual parameters such as ammonia and nitrite. As these conditions favour the growth of algae, an ultraviolet clarifier is usually an essential piece of equipment to maintain the clear water that allows you to appreciate your pets.
As well as a few variations such as White ghost and Golden ghost, these fishes may also be seen on sale as Ghost Carp.
As Koi are now reclassified as Cyprinus rubrofuscus and Common carp remain Cyprinus carpio, these fish should now be considered hybrids.
Feeding
Good quality specialised diets are available for all sizes of these fish including pellets and sticks. Take care to avoid the temptation of overfeeding - adding food little and often will soon train the fish to associate their owner with food. Feeding is linked to temperature and it's important to offer a cold weather formulation in late autumn, winter and early spring. Prawns, earthworms, lettuce and even orange segments are all good treats to be fed now and again.
Breeding
Although Ghost Koi are able to reproduce with one another, expect a high percentage of offspring that revert to the original parent fish. Spawnings will occur naturally in the pond if sexually mature males and females are present, where conditions are to their liking (water quality, water temperature, light levels etc), and where there is a medium such as mops/ropes/brushes where the eggs can be scattered. However, many spawnings go unnoticed as the eggs are often consumed quickly by the parents and other fish in the pond (and even other predators such as dragonfly larvae, snails, and tadpoles). To ensure survival of the eggs/fry, the aquarist will usually have to intervene, collecting the eggs before they are devoured, and keeping them in a spacious container with pond plants and some continuous form of gentle oxygenation. The eggs typically hatch within 4-5 days, and the fry will feed on their yolk sacs for the first few days, after which time a constant supply of small live foods such as infusoria and daphnia will be required. Koi, of course, can be selectively bred in separate breeding ponds if the aquarist is fortunate to have access to this type of set-up. In this scenario, the water of the breeding pond should match that of the main pond, and it should be lined with spawning ropes and the like. A well-conditioned selected pair can then be added and observed regularly for signs of spawning. Once the eggs have been deposited over the spawning medium, these can be separated from the parents and grown on in an independent container as described above.
