With six years of phd work on theropod dinosaurs behind him, Darren Naish mostly spends long hours in the library, hunched over his laptop. But he gets out sometimes, and picks up litter and pursues exotic lizards across the British countryside, aiming all the while to publish his technical work on obscure Cretaceous dinosaurs. He also messes around with pterosaurs, swimming giraffes, British big cats and stuff like that. He has given up on the stupid idea of being a dedicated academic and ekes out a living as a technical consultant, editor and author. He can be contacted intermittently at eotyrannus (at) gmail dot com. For more biographical info go 
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.
Life Science
Environment
Comments
You can blog on octopuses. As I learned in church this weekend, they're just two tetrapods sewn together.
Posted by: Jason | January 30, 2008 9:54 AM
Holy crap I need that book! Snappers are my favorite turtles!
...aren't they everyone's?
Posted by: Zach Miller | January 30, 2008 2:38 PM
Yeah, we've all been waiting...and waiting...and waiting for the snapping turtle book. Mike Finkler swears it's done and coming out soon.
Let me know when you next make it to the east coast of the USA and we can go out and trap some...they're far more awesome in a hoop trap and in hand than they are in a tank!
Posted by: Sven DiMilo | January 30, 2008 3:26 PM
Certainly more awesome than when your hand is in their beak.
Posted by: David Marjanović | January 30, 2008 4:59 PM
Awe-inspiring,rather. I was once seized by the elbow by a medium-sized specimen and it was quite impressive, how much force was exerted and, actually, that it could get my elbow (epicondyle to epicondyle) into its maw.
Posted by: Lars | January 30, 2008 5:40 PM
p.s. wild ones, of course, are never so nice & clean as that guy in your pics!
Posted by: Sven DiMilo | January 30, 2008 6:59 PM
Snappers are fantastic! My vote for coolest turtle feeding has to go to the matamata, however. I'm still hoping to get a good shot of my mata engulfing a meal, but it takes very good timing and wicked shutter speed...
Cheers,
--Mike
Posted by: Mike Habib | January 30, 2008 7:35 PM
Mike - have you seen...
Lemell, P., Lemell, C., Snelderwaard, P., Gumpenberger, M., Wochesländer, R. & Weisgram, J. 2002. Feeding patterns of Chelus fimbriatus (Pleurodira: Chelidae). The Journal of Evolutionary Biology 205, 1495-1506.
... includes neat high-speed and x-ray photography of engulfing behaviour in matamatas.
And Sven - do we have a date then? Not sure when I can make it over but I'll let you know :)
Posted by: Darren Naish | January 30, 2008 9:55 PM
'twould be my pleasure, and I'll throw in 3 or 4 other species for nothin'
Posted by: Sven DiMilo | January 30, 2008 10:04 PM
Thanks for the citation! I do indeed have that paper, and it is quite good (one note, though: it is in the Journal of Experimental Biology, rather than Ev. Bio). At the same time, I think much more can be learned from that particular feeding dynamic. For one thing, I have noted that the maximum prey size for matas is quite large. My mata can easily take prey slightly longer than his head, and I've had zoo animals do the same (not that I do this often, as I expect such meals are larger than would typically be eaten in the wild). The fluid forces involved must therefore be pretty impressive, and calculating the required power would be a lot of fun. The sensory requirements for aim and rapid response might also be of interest.
Posted by: Mike Habib | January 30, 2008 10:52 PM
That's a very odd looking snapping turtle. Is it an albino? Every one that I've seen has been dark grey. Of course, this one lacks the accumulated algae and sediments that coat most wild specimens, so that might make some difference. But even cleaned museum specimens are much darker than this guy.
Posted by: William Robertson | January 31, 2008 1:41 AM
Oh yeah, J. Exp. Biol, not J. Evol. Biol., how dumb of me. I think matamatas look terrifying - especially the big ones. But that doesn't mean I don't love them. Some books say that the name means 'kill kill kill', which seems like a mightily odd name to give an animal.
I agree that the Blue Reef snapper is unusually pale, but it's not an albino. It looks like it was kept in the dark for years, but its enclosure isn't particularly poorly lit, and I know nothing of the animal's life history. Maybe it is just an unusually light-coloured freak.
Posted by: Darren Naish | January 31, 2008 6:20 AM
Let's not neglect to note that Jason's remark above is funnier than anything I have posted on TetZoo. The tetrapods in question, by the way, must be the boneless aquatic pterosaurs previously under discussion.
Posted by: Nathan Myers | January 31, 2008 10:06 PM
During one of our many trips to the upper Texas Coast in my university years, a friend of mine decided to wade across a brackish pond or inlet, while wearing a pair of canvas tennis shoes to protect his feet. The water was deeper than he expected, and he ended up swimming for a short stretch...he swore that something grabbed his shoe, and almost pulled him under the surface briefly. He was sure that the "something" was a large snapping turtle.
The bayous that criss-crossed the city in which I grew up were not lined with concrete until fairly recently, and it was not uncommon to have turtles and snakes show up in the backyard, especially after heavy rains. One day, our Shetland Sheepdog was barking furiously at something in the passageway on the side of the house, and that something turned out to be a very large Alligator Snapping Turtle. The two Bloodhounds in the yard next door were also going berserk and baying, and the angry turtle was not exactly an easy creature to relocate. I think my dad ended up lifting it into a wheelbarrow, and taking it to the nearest bayou.
Posted by: Barn Owl | January 31, 2008 10:15 PM