For some time there has been a debate about the causes of the so-called “whirling disease” in discus fish (Symphysodon) and other tropical ornamental fish species. I hope via this article to inspire further research and discussion and highlight some of the facts and myths surrounding this problem. The illness itself is known to cause fish to whirl violently in a circular manner often with no apparent or obvious cause and usually die some short time later. Many theories have come about as to how and why this strange behaviour occurs ranging from infectious organisms to dietary deficiencies or even …
