Friday, September 05, 2014

Shark ID - Help wanted!

These are Bulls Sharks - click for detail!

Check this out!

What are those Sharks among those Grey Reefies?
Methinks Dusky/Galapagos (but possibly Bronzie?) and.... Pigeye (!!!) - the latter because she doesn't feel like a Bull, and because I read that from C. amboinensis, the bull shark differs in its lower, less erect first dorsal fin and higher, more erect second dorsal fin. The ratio of first:second dorsal height is 3:1 or less in C. leucas, but over 3:1 in C. amboinensis.

Opinions please!
JSD - David?


jsd said...

(1) silky
(2) how big is it? And that seems to be a lot of wideangle/fisheye distortion which doesn't help. The first dorsal looks rather puny for the pigeye (and it would be a very lost pigeye!)... You've seen plenty of bulls in that corner of the world, Mike, and if it doesn't feel right for a bull for you I'd hate to hurt your feelings. So I'll say Parascyllium collare.

DaShark said...

Gee, thanks! :)

So, a Silky huh - I've seen to few of them, too long ago to venture a strong opinion, so a Silky it is!

Re the Pigeye.
Because of the similarity to the Bull, the distribution is rather fragmented as people do confuse them - but of course it would be a humongous range extensions, and Tonga does have Bulls.

And yet.
That first dorsal irritates me. In your typical Bull, it is nearly an equilateral triangle, and slightly falcate. This one appears way too steep and narrow - but granted there is distortion.
And the height ratio is way above 3:1.


Johann MOURIER said...

Hey Mike, for me it seems to be a pregnant dusky shark (C. obscurus)... but hard to be sure...

DaShark said...

Johann: the first or the second Shark?

Johann MOURIER said...

the second one, the last one bumping the camera

DaShark said...


You're just saying that to further befuddle me - right? :)

jsd said...

Silky: this is a chunky one! Position and shape of first dorsal, no pronounced fin markings, and the clearly visible very long free rear tip of the second dorsal.

The second shark: the first dorsal looks better for a dusky and also the dusky fins. So if there is a huge amount of (barrel) distortion I would agree it might be that.

Johann MOURIER said...

I am not sure but there are a lot of common characteristics... I am more on the dusky shark than the Pigeye for sure... but not 100% confident.
it's just my opinion, maybe I am wrong...

DaShark said...

Thanks gents - you are truly a cornucopia of erudition! :)

Me, it appears, not so much! :(

OfficetoOcean said...

I think they're both Duskies. I did think at first the first shark could be a silky because of that dorsal fun but the colouration and eye don't fit.

2x Dusky for me.