The question of “Injured Fish” – John Cramer

Occasionally a fish will be presented at a weigh station with an injury.

Several questions then arise as to whether the injury has occurred prior to landing the fish, whether it sustained the injury prehook-up, during the fight, or, post landing and prior to presenting it at the weigh in.

Over the years I have both been involved in and or witnessed, many such incidences.

Only occasionally, a further question can also come into play as to whether the reason(s) behind such injuries are genuine or not, the bottom line is.

If a fish is presented at the weigh station with a ‘fresh’ injury, whether the result of a shark bite, prop damage or other obvious mutilation the fish should be disqualified. (Apart from obvious gaff marks, bleeding and gutting fish). Unfortunately, this can also possibly mean that an angler might miss out on a shark capture (if sharks happen to be a fish that can be weighed). The reason behind this, is that female sharks when mating, can sustain quite significant injuries from their male suiters.

Photo 1 – Old wound of the underbelly of a WA tailor

Photo 2 – Bite out of the back (behind the pectoral fin) of a Spanish mackerel – old wound.

Photo 3 – Old wound at the side of a WA spangled emperor

Generally speaking, if a fish has sustained an injury prior to capture and the injury has had time(?) to begin to heal, although the injury may appear relatively new, a ‘film’ over the wound can be seen.

Photo 4 (Courtesy of Dr Julien Pepperell)

Teeth marks in the tail section of a female mako shark indicate a definite bite or series of bites by another mako. At the time, the bites were considered to be recent mating bites (i.e, a natural event). However, looking at them again, especially the location and severity, I’m inclined to think this was very likely an attack on the mako while it was hooked. Mating bites would typically be around the shoulder area, while it is well known that large makos predate on other large fish (especially billfish) by biting the caudal peduncle to sever the tail. The latter looks to be the most likely explanation. (1) 

Photo 5 (Courtesy of Dr Julien Pepperell)

The badly injured striped marlin that had partially healed. This was a severe injury, interpreted as possibly being caused by a prop. That injury had definitely occurred well before the fish was caught. (2))

The time line for wounds to heal and the science behind this, is something that has been studied by those who research various marine life in order to determine whether there are any genetic healing properties within their biology, which might be medically beneficial and applied to the human healing process.

The fish skin is a multifunctional tissue with suitable physical and mechanical properties, and most importantly owning excellent antimicrobial properties against pathogens can be an ideal alternative for skin regeneration (3)

Article by : John Cramer

References:

(1)   Comments by Dr Julian Pepperell. Pepperell Research & Consulting Pty Ltd

B.Sc. (Hons) Ph.D.

• Comment by Dr Julian Pepperell. Pepperell Research & Consulting Pty Ltd

B.Sc. (Hons) Ph.D.

• Fiakos G, Kuang Z, Lo E. Improved skin regeneration with acellular fish skin grafts. Eng Regen. 2020; 1: 95- 101.