Thursday, May 19, 2011

Bull Shark First of 2011

     This little two footer showed up Sunday night and swam around the light's perimeter for an hour. A shark probably in his first year, he is the earliest of the summer bull sharks to show up in West Galveston Bay this year. I typically see his big elders on the redfish flats in starting about mid-June, which begs to question: why so early for the little guy? Well, one explanation is that, with most bony fishes anyway, the younger fish are more temperature tolerant, which explains why you will find few small frozen fish after a hard freeze, but find MANY big fish. This is an evolutionary advantage for any species survival, as it allows the young to survive sudden seasonal changes while in their nursery, typically removed from the open ocean bodies in a more isolated bay/estuarial system. No reason the cartilagenous fishes would not take advantage of this hardiness, either. How do I know she's a bull shark, Charcharhinus leucas? The sharply rising high dorsal and blunt snout are big "tells" on speciation with these buggers. Please forgive the fuzzy photos, but you should be able to see these traits  nonetheless.
     Should be a year of high predation, hopefully with me at the TOP of the food chain and not in the belly of this little guy's grandparent. Oh, yes: Bull sharks eat people. They've charged me. They have been found to be responsible for more attacks on humans than any and all other species of shark. These are the attacks that the "professionals" know about, only. There are many more. When one is alone, there is no one to record or report an "event". This is when this species is extremely aggressive towards humans--they know by the sounds and impulses in the water exactly what's going on. So, only the shark knows each of his meals. He is the REAL expert of his own behaviour. And those in the water with him often--lone anglers such as myself, know him pretty well, too. They DO love stingrays. Poor frienly water-flying guys!

Here's the slinky swimming motion of a relaxed shark illustrated: you can "click" this image for a closer look

And here's that profile with the high dorsal and schimitar tail: you can "click" this image for a closer look, too.

I must work on getting better night shots.....the silhoueted subject in the light confuses the "intellignet" digital camera.

Oh, I tried to bind this shark to my DX6i Spektrum transmitter. No dice!
Back to Research and Development!

No comments:

Post a Comment