Will and I looked at some really awesome creatures on our recent visit to the Blue Reef Aquarium at Southsea (Portsmouth, UK)… but most of them weren’t tetrapods so I won’t be blogging about them. Sturgeons, wobbegongs, remoras, horseshoe crabs, four-eyed fish, Pacific giant octopus, moray eels. I actually spent ages trying to get a good photo of a wobbegong but couldn’t. Anyway, I had better luck in photographing the Snapping turtle Chelydra serpentina shown here – though it took ages as it wouldn’t keep still. I like my photos for several reasons. The adjacent one, for example, shows the animal doing a very nice neck-stretch – more normally these animals are shown with their necks retracted, making them look rather short-necked.
Check out the close-up of the head shown here (sorry it’s a bit dark). What’s with those barbel-like structures on the lower jaw? Are they simply there to help disrupt the animal’s outline and aid its camouflage, or do they have a sensory function like the true barbels of fish? I can’t recall reading about them in the snapping turtle literature. The spikes on the back of the skull are also cool. Also emphasized here is how close the eyes are to the snout, and – if you imagine the skull without all the soft tissue in the way – how long and tall the back of the skull is, particularly the sagittal crest.
I’m trying to resist the urge here to talk about the fascinating and dynamic feeding behaviour of these turtles as I covered it all before on ver 1, so if you want to learn more about snappers and how awesome they are what more can I do than recommend my own previous series on them: please see They bite, they grow to huge sizes, they locate human corpses: the snapping turtles, part I, then Snapping turtles, part II: hyperexcitability, supercooling and recolonisation of Europe in the Anthropocene, and finally Snapping turtles, part III: bite, lunge, lure and snap.
A few things have been published on snappers since I wrote those 2006 articles. De Solla et al. (2007) looked at the concentrations of industrial pollutants in Canadian snapper eggs (there is a reasonable amount of literature on contaminant levels in snapping turtles, for a good review see Christine Bishop’s article here). But most exciting is Anthony Steyermark et al.’s new book, The Biology of the Snapping Turtle (240 pp., John Hopkins University Press), due to appear in Feb’ 2008.
PS – this was sort of meant to be a ‘picture of the day’ piece.
Refs – -
De Solla, S. R., Fernie, K. J., Letcher, R. J., Chu, s. G., Drouillard, K. G. & Shahmiri, S. 2007. Snapping turtles (Chelydra serpentina) as bioindicators in Canadian Areas of Concern in the Great Lakes Basin. 1. Polybrominated diphenyl ethers, polychlorinated biphenyls, and organochlorine pesticides in eggs. Environmental Science and Technology 41, 7252-7259.