crucian (KROO-shen) - n., a medium-sized greenish-brown European carp (Carassius carassius), also called crucian carp.

Thanks, WikiMedia!
Raised by humans both for eating and as an aquarium fish. It hybridizes easily with goldfish (C. auratus), and it was formerly believed that goldfish were a domesticated variety of crucian, but genetic studies have shown goldfish were domesticated from its own species. The name is from Low German karuse, from Middle Low German karusse, of uncertain origin, possibly Medieval Latin coracinus, a kind of river fish, or possibly of Baltic origin.
---L.
Thanks, WikiMedia!
Raised by humans both for eating and as an aquarium fish. It hybridizes easily with goldfish (C. auratus), and it was formerly believed that goldfish were a domesticated variety of crucian, but genetic studies have shown goldfish were domesticated from its own species. The name is from Low German karuse, from Middle Low German karusse, of uncertain origin, possibly Medieval Latin coracinus, a kind of river fish, or possibly of Baltic origin.
---L.