Red Tail Giant GouramiRed Tail Giant Gourami The Giant Gourami Osphronemus goramy is a stunning fish when it gets large. In their natural environment natives have reported lengths of almost 60 cm. It has even been suggested by Vierke (1978) that it can get as large as 70 cm. Now that is one big gourami! Fortunately in captivity they are scarcely over 40 cm and it's only a rare specimen that reaches close to 45 cm. But that is still a good sized fish. This is the largest of