saddleback deformities in yellowfin bream

Yellowfin bream are an important commercial net and angling fishery in Moreton Bay, and hold cultural significance for Traditional Owners as evidenced by the skeletal remains found in middens around the Bay. But have you ever caught one in Moreton Bay with the deformity shown above and wondered what caused it?

Friend of Moreton Bay member Barry Pollock is a keen fisher and has been researching these saddleback deformities in yellowfin bream in the Bay. He’s just published his third peer-reviewed journal article reporting further evidence that this deformity is caused by physical injury.

Barry reports yellowfin bream with this deformity have been reported from Hervey Bay to south of Sydney, but Moreton Bay is a hot spot with a persistent incidence as high as 10% in fish larger than 25cm. X-rays and chemical tests of fish tissue do not show any reason for the deformity. Their popularity in the net fishery may be the cause as fish smaller than the legal minimum size are discarded from nets.

Barry’s paper is open access and may be viewed via the link below.  Pollock, B. (2021). Causation of Saddleback Deformities in The Yellowfin Bream Acanthopagrus australis Fishery: Evidence of Physical Injury. Asian Journal of Fisheries and Aquatic Research, 10(4), 35-48.