|View single post by STB|
|Posted: Wed Nov 2nd, 2016 09:30 am||
|Email I received from Dr Clive Roberts
Thank you for your email and interesting photos attached.
Based on relative body depth and colour, I think your fish is a hapuku Polyprion oxygeneios (family Polyprionidae).
It is hard to get a suit of characters from photos, so my identification is subjective and not 100% definitive. However, I have been working on this group for over 30 years and know both species well as juveniles and adults, and can be reasonably confident that it is not a wreckfish (P. americanus).
Unfortunately, my home computer will not download the photo images posted on your Sealine discussions.
As this fish is an important record for South Africa and the species, I would be most grateful if you can give me its location and depth of capture. I presume that you caught it on rod & line.
Hapuku are found all around the temperate southern hemisphere, including oceanic islands in the south Atlantic and south Indian oceans. So, it has always been a puzzle to me why not in South African waters. I suspect the simple answer is that hapuku do occur off South Africa, but has always been misidentified as wreckfish. To be certain about this we need at least one specimen donated to the collection of either the South African Museum, Cape Town, or to SAIAB – South African Institute for Aquatic University – at Grahamstown (see Ofer Gon cc above).
So, if you catch any more, especially smaller than this large adult, I suggest that you freeze it and contact whichever fish collection is nearest for their instructions on pickup and delivery. Sorry, I know they are very good eating!
Also, I think that your observations on bluenose captured off South Arica are also important. However, I am currently on leave and do not have access to a fish library, so cannot easily check the world distribution of this fish. But happy to do a follow up in December, when I return to work in Wellington.
Best wishes, CLIVE
P.S. The two species of Polyprion are genetically distinct, but it is important to compare the most variable markers – although COI should have pick this up. Possibly there is, again, a problem with original identifications of the fish sampled?
Dr Clive Roberts
Curator of Vertebrates (Fishes)
Museum of New Zealand Te Papa Tongarewa
169 Tory Street, PO Box 467,
Wellington, New Zealand