Friday, May 17, 2019

What Shark is this??

Notice the caudal peduncle - click for detail!


This is from the second 15m dive at Shark Reef a few days ago. 
For once I was not diving, and the footage is courtesy of Martin who is here for his yearly Bull Shark fix. I'm being told that the Shark was curious and circled above - but with a gaggle of Bulls dominating the feed, she remained wary and never tried to join the mêlée. 

At a reported 3 meters in length, this is a big Shark.
When they first told me, they stated that she was an emaciated, sickly Bull Shark - but from the video I can instead discern that despite of the tumor and the buckled first dorsal, she is in rather good shape. I also notice the elegant sinuous way she moves, and the keel-like bulge on her caudal peduncle, both of which are not at all diagnostic of Bull Sharks, sickly or otherwise.

So what is this?
Years ago there was another mystery Shark with a similar shape of the caudal peduncle. Back then, somebody stated that it was a Dusky - but that's a Shark living off continental shelves and we are obviously on an island, so today I'm rather skeptical.

I got my thoughts but would love to hear yours.
Opinions welcome - here on the blog and not on Facebook please!

Thank you!


Unknown said...

Looks like a Galapagos Shark to me. The bull photobombed at just the wrong moment to have a better view. Silky’s Look and move like a Porsche, sleeker, pointier. This one had darkened trailing edge of caudal...something you see on Galapagos.

Michael Domeier

DaShark said...

Thank you! :)

I've dived with both Galapagos' and Silkies but do not really "know" them, if you get what I mean; but I've come to the same conclusion coming from the other end, i.e. that the Galapagos' I've met (mainly in Wolf, Galapagos Islands) are somewhat sinister and exude power, more muscle car than Porsche - which to me this Shark embodies.

And I definitely concur that Silkies are pointier - whereas this pic of a silhouetted Galapagos Shark appears to be an excellent match!