Name this Dorsal Fin?

[Scubagirlfl]

Hi, I know this is a stretch, since the photo is so bad, but can anyone help figure out what type of fish this fin belongs to? I was on my boat at Hens & Chickens Reef (Florida Keys) when I saw this. We jumped in to see it better, but it disappeared (viz was not good that day). It was tall, fairly skinny/thin, Silvery/Gray.

TIA

 

[diverdoug1]

By your description, it may be a Swordfish.

 

[Scubagirlfl]

Thank you! That makes sense, there was alot of Ballyhoo around.

 

[mntlblok]

The tall, sharp fin reminds me of a hammerhead shark. Also, I remember once seeing a hammerhead cruising on the surface like that while fishing off the Pacific coast of Costa Rica.

I've been working my way through this "Name that Critter" forum and I've become addicted. :d

Kevin
Savannah

 

[designbysue]

Scuba divers are such an interesting bunch! Most people would run screaming from a fin - we jump in to see what it is.

 

[J Easy]

Possibly a Great Hammerhead. They are fairly common out there I hear.

 

[garyd54220]

From what can be seen of both the fin and the body of the fish under water it kind of looks like an ocean sunfish (Mola Mola). Don't know if that's even possible in that area, just saying that's what it looks like. Could certainly also be a Great Hammerhead by the shape. Its just that there doesn't seem to be much "fish" visible under water and what's there kinda looks like part of a Mola Mola. But hey, what do I know.....I live on Lake Michigan.
Gary

 

[livi120]

From what can be seen of both the fin and the body of the fish under water it kind of looks like an ocean sunfish (Mola Mola). Don't know if that's even possible in that area, just saying that's what it looks like. Could certainly also be a Great Hammerhead by the shape. Its just that there doesn't seem to be much "fish" visible under water and what's there kinda looks like part of a Mola Mola. But hey, what do I know.....I live on Lake Michigan.
Gary

Mola mola was the first thing that popped into my mind when I saw the pic. We have 3 kinds of Molas in this area that I know of. The Ocean Sun Fish (Mola mola), the Sharp Tail Mola (Mola lanceolata) and the rarer Slender Mola (Ranzania laevis). And I think this could be Ocean or Sharp tail. However there isn't really much fish to go by. And what I think you and I are seeing "in the water" can just be tricks of the light, I don't think you can really make out any sort of shape in the water.

As far as shark, it's just that the fin seems a little tall and narrow and too wrinkly for a shark (but again it can just be the photo angle) if it is shark the shape is most like a great-hammer.