Tuna ID

[zar2754]

http://www.mexfish.com/fish/beyetuna...geyeTunaID.pdf

easily best id guide on the net


and its 100% a yft. not a big eye

[Roddy Hays]

GOOD GRIEF !! That's the 3rd bloody link. Do people never read threads ?

Ultralite - I have caught probably over 2000 bigeye, and I have seem many, many skinny ones. It's a seasonal thing. I also have caught many with short pectoral fins, which happens when they get over 100lbs in weight. They also display a fine colouration too, as in the photo below, which is of a Canarian big-eye.



It is the caudal notch that got me, as it resembles a YF distinctly, and I do not recall seeing a Madeiran big-eye with that before.

After looking through my Madeiran photos, I've found most of my tuna stuff is still on film and tucked away somewhere, but I did find this picture from 2007, in New Zealand. Looks like their big-eyes have the same caudal notch too !



I still say we need the liver..... sigh

[Captain Michael Buffington]

To me, at least, this continues to be an interesting discussion. Opinions, particularly those based on actual experience, are good and we can all learn from them.

Roddy has had a lot of experience with tuna the world over, including lots of hands on the bigeyes. As stated, I am with him and the others when it comes to IDing bigeyes. Split 'em open and we can be sure.

One of the things that convinces me that it's a bigeye is Roddy's statement that there hasn't been a yellowfin documented in Madeiran waters for over thirty years. That pretty much says it all as far as I'm concerned.
One potential reason for the fish being so skinny might be the damage done to its mouth and upper jaw. Bigeyes have a key body and head shape factor that produces a "pressure wave" just in front of its head. Myself and others believe that this has something to do with how they feed - specifically using it to shock and/or stun prey. Those wounds look old and scarred over, so this might have impaired that particular fish's feeding ability. Of course, I don't know for sure, but it is worthy of consideration, I think.

That pressure wave is why short, heavy jets are highly favored by those who fish for them, especially the commercial rod and reel guys. I've pictured one of mine below. It is from the Bigeye Troller's Bible book. The why's and wherefore's of this and other aspects of these very different fish are discussed in great detail in that book. In time, we switched over to specialized spreaderbars because, as it is with all tunas, more "chum" in the pattern gets noticed and attracts more fish than a couple of single lures. This made the multiples that we loved so much on those very valuable fish happen a lot more often.

The jet in the pict has been wahoo-chawed...sorry!

I don't know about the rest of you guys...But I am convinced by that statement...I myself have no idea. I had trouble differentiating between the two on the long range boats. The best way for me to tell was if it was cold water on the troll and over 100lbs it was a bigeye...Not very scientific but...

Very interesting discussion!

Mike

[scattered_grass]

GOOD GRIEF !! That's the 3rd bloody link. Do people never read threads ?

Ultralite - I have caught probably over 2000 bigeye, and I have seem many, many skinny ones. It's a seasonal thing. I also have caught many with short pectoral fins, which happens when they get over 100lbs in weight. They also display a fine colouration too, as in the photo below, which is of a Canarian big-eye.



It is the caudal notch that got me, as it resembles a YF distinctly, and I do not recall seeing a Madeiran big-eye with that before.

After looking through my Madeiran photos, I've found most of my tuna stuff is still on film and tucked away somewhere, but I did find this picture from 2007, in New Zealand. Looks like their big-eyes have the same caudal notch too !



I still say we need the liver..... sigh

That top picture is amazing sir!

[Patudo]

There have been a very small number of yft caught on rod and reel in the Madeira area within the last thirty years. One was caught last year, in fact by the same captain and boat in the photo at the beginning of this thread. They are very rare compared to bigeye but every so often one will show up. I find it a little odd why so few yft visit the area since yellowfin are caught in many areas where ocean temperatures are the same or cooler. The wahoo fishery can be pretty good and you would expect wahoo to be less tolerant of cool water than yft.

That photo showing Richard and Tony releasing the tagged bigeye - if you (Roddy) hadn't told me it was a bigeye and I knew it was highly likely to be one given where it was caught, I might have hesitated to identify it as one. The angle of the fish and camera and the fact you don't see the whole fish makes it hard to judge body depth and proportions. You'd still expect a fresh yellowfin to be even more lit up but colouration can be deceptive and there is the possibility the camera's autoexposure may not record the colours exactly. I wonder if that might be the case with the photo in the original post. I'm thinking it is a skinny bigeye because (a) the odds are it is a bigeye given where it was caught - but you can't rely on that alone since (for instance) just because the great majority of marlin caught at Cairns are blacks doesn't mean you should exclude the possibility of a blue, (b) I'd still expect the second dorsal and anal fins of even a short finned yft to be longer and yellower (sp?) than what I see and (c) that bronze looking colour in the fish is something you definitely notice in bigeye, whereas YF have more of a golden look to them.

But I'm perfectly prepared to accept I could be wrong. Looking through the David Itano guide I am struck by just how chunky-looking those Pacific bigeyes are, and that fish is very slender for a bigeye. But then YF differ in chunkiness too.

[Patudo]

OK what about this one?

[Capt. kapoc]

its a eyeball

[Patudo]

I think so too. But, although it may not be obvious in the photo this fish has a notch in the tail.

This really gets me wondering are there any significant morphological differences between Atlantic and Pacific bigeyes.

Here's another one with a notched tail. Thoughts on ID guys?

[Roddy Hays]

Interesting, Dustin. As I said on the other thread on Josh's forum, I've had a hunt around for some more Madeiran BE pics. Here's a few....


This is a Swedish friend called Peter - he's a huge guy and the fish is about 75 kilos or so. Spring fish.


This is some forgotten fella with a BE with a notched tail in which his thumb is resting. Winter fish. This picture shows a very strange BE too, any idea what's strange about it ?


Capt Joao, who is a man with several thousand tons of BE under his belt, with a nice BE right out in front of town. His fish also has a notched tail. Spring fish.


Paul McKenna and Joao again with the result of triple-header on a spread of marlin lures - summer fish.


Joao with another nice spring fish.


And the last pic is of a small fish caught in the summer under a floating rope. We caught about 20 of these, and as we were cleaning them by the wall, Joao peered over the edge and asked where we had caught our "patudo" - BE. I laughed up at him and said he obviously couldn't recognise a YF when he saw one. No, he insisted, jumping down to the deck, they're all BE.

As we had caught every single fish on 8lb, my ears pricked up (and my heart sank - for we'd gutted every damn fish by that stage) - as the record line slot was open. Robert (the crew that year) and I checked every single fish - they all had striated livers, and Joao was absolutely correct. They all "looked" a little/lot like YF, complete with notched tail, but they were in fact BE. Indeed, when cutting the fish into steaks for the freezer you could instantly tell that they were BE and not YF.

So, in conclusion, IMO I really do think there there are some morphological differences between Pacific and Atlantic BE which need to be looked at carefully. I know there is very unlikely to be any cross-breeding between the species, but I wonder if it may ever happen, and if some of the fish we catch and are confused over may be the result. Any biologists out there care to chime in ?

I might add, that looking through the ID pfd that's been posted here, I have never seen a juvenile BE in Madeira with those long droopy pecs. Never. And as the spring fishery is composed mostly of small 20 - 75lb fish, I find that surprising.

Dustin - what boat is that pictured in your last post ??

[BahamaLure]

the unusual tuna pictured lacks the lower anal fin....

I also notice very clearly in all the BE photos how much squatter they all are compared to the opening shot of a very much more elongated fish indicating its identity as a YFT. Here is a BE caught off Oregon Inlet on one of my Triton lures clearly showing the body shape of a BE.