Black spot are a common disease of goldfish caused by the larvae of parasitic digenetic flukes, Cercaria and Metacercaria. This parasite (larval trematode) burrowing into the skin of a fish causing the formation of a cyst approximately one millimeter in diameter. This larvae has a complex life cycle that requires fish eating birds or mammals, snails, and fish at different stages in order to survive. Usually black spot only happen on fish that life in earthen bottom ponds and lakes.
The term "Black Spot" refers to the formation of small cysts in the muscle and skin around which the parasite lives. The cyst accumulates black pigment cells. These cause little harm to the fish. Young fish have growth problems if heavily infected. The first intermediate host is a mollusc. The fish is the second intermediate host and the final host is a kingfisher or heron.
Heavy infestations of these parasites do relatively little damage to the fish particularly on young fish that may experience excessive blood loss, physiological stress, and even death. More dangerous if a fish has heavy infestations on the eyes that may cause they blinded.
Symptoms that appear because of Black Spot
1 Scratching against surfaces
2 Small black speckles on body
3 Small black smudges on fish
4 Very irritated
5 Flickering
Heavy infestations of these parasites do relatively little damage to the fish particularly on young fish that may experience excessive blood loss, physiological stress, and even death. More dangerous if a fish has heavy infestations on the eyes that may cause they blinded.
Symptoms that appear because of Black Spot
1 Scratching against surfaces
2 Small black speckles on body
3 Small black smudges on fish
4 Very irritated
5 Flickering
