18 August 2011

Reptilia

Firstly, I forgot to mention something crucial in that last post! Along with the 4 courses I'm officially taking this semester, I'm sitting in on the Human Evolution course for funsies. I wish I could properly take it and actually be registered for it but a) I don't have space and b) it'd be silly because it technically won't help my degree much. But that's not the point! What a brilliant course! The convener, Becky Ackerman, is so amazing. She gave us a few lectures on human evolution in first year biology but here she has a whole course of her own! It's so interesting and she's a great lecturer. Plus she's apparently uploaded a bunch of articles on why creationism is nonsense. Evolution is such a beautiful thing to study. More on that in the next post though :)

The Animals course, gosh. It's still amazing and Mike Picker is still the most passionate lecturer I've seen (showed amazing footage of a cicada moulting today!), but these pracs are going to get harder for me I think... We had to dissect a nice, big, red and poisonous locust on Monday. Three hours of holding it, cutting away at exoskeleton and organs :S I've mentioned before that I have a teensy insect phobia. This course should hopefully be the end of that. Absolutely terrifying. I got told off by Mike for swearing when I first had to pick it up with my hand. But all that aside, I actually enjoy dissections. When it comes to vertebrates I do have some ethical issues with it (huge grey area, still undecided), like when we did the frog last year, but with invertebrates, it's icky at first but once you've cut away all the things that make it look like a living thing, it's actually fascinating. And for someone who wants to throw up/cry before every dissection I'm kind of good at them weirdly...

Anyway, around this time last month I was in India, sick in bed and watching Animal Planet for hours when this Donald Schultz documentary came on. I don't know much about him since I've only seen his stuff a couple of times, but he's one of those Austin Stevens/Jeff Corwin adventure types. He's South African and mostly seems to work with snakes, got a bit of a Bear Grylls vibe about him except he's actually cool (I hate Bear Grylls!). From what I've seen he always seems to be on these quests to find some dangerous/rare animal for scientific purposes like to milk for venom, get tissue samples etc. For anyone who doesn't know, I'm a bit of a reptile freak. Big cats, sharks and snakes are generally my thing so these documentaries excite me. What I loved about this show was that he was exploring the deserts in Iran, somewhere no one ever goes. He found this stunning desert monitor, the picture below shows one, absolutely beautiful animal.


What I really want to talk about though is venom. Venom, not poison!! It does my head in when people mix up the terms. If it's injected into the bloodstream with fangs or any other way, it's called venom. It's poison when it's ingested or absorbed. So there is no such thing as a poisonous snake! That's such a huge pet peeve of mine. Yes I'm a dork :) Anyway, it's generally always been thought that snakes were the only venomous reptiles, with the exception of two lizards; the gila monster and Mexican beaded lizard. Over the last few years though, they've been finding a whole bunch of lizard species that are actually venomous. This article's actually really old but I only found it after watching this show and Donald Schultz said that these desert monitors could in fact be venomous. Till now it's always been assumed that the side-effects of lizard bites were just because of all the bacteria in their saliva. A classic example being the Komodo Dragon. There are so many documented cases of how their saliva is so full of bacteria that when they hunt, the infection from their bite is guaranteed to kill the prey within a couple of days. So they bite, wait for the bacteria to do it's work, and follow the buffalo or whatever prey around until it dies. Wrong. Well, partially. Their mouth definitely is full of bacteria and all sorts of nasty stuff, but it turns out they have venom too. So if a Komodo dragon wasn't already intimidating enough, it's venomous too. They've found that most of the venomous lizards are in the iguana and monitor families. Even the bearded dragon, a popular pet, has been found to be mildly venomous. It really makes you think about the evolution of these reptiles. I've always thought of venom as quite an advanced and recent adaptation but if the ancestors of modern monitors could have venom, what about venomous dinosaurs? I'd never thought about the possibility before.It's amazing. Read those two articles and if you're interested in venomous things, have a look at some of the other work Bryan Fry has done. He makes a lot of random appearances on Animal Planet and Nat Geo but I've just rediscovered him now with this, must have a look at the site myself...So interesting. I love reptiles. I'm trying to convince my dad to let me do this snake handling course but I don't think he'd be so excited about giving me money to play with Cape cobras... 

Actually since I'm on the topic of venomous snakes. This is my favourite -

Bitis gabonica
The Gaboon viper, such a remarkable snake! Such perfect geometrical markings - impeccable camouflage, the two little horns on it's nose, it's the heaviest of all the viper species with the longest fangs and biggest venom yield of any venomous snake. They used to have this beautiful one at the Jo'burg zoo, I saw it presumably just after it had shed and its skin looked almost velvety. But they don't do very well in captivity so it's not around anymore :S But they did get a rhinoceros viper instead. Actually the two are very closely related. Rhino viper, another favourite, they're smaller but look quite similar to Gaboon vipers. Their colours are brilliant though, and so varying depending on their habitat. I'm going to stop there because it's too easy for me to go on about snakes.

And speaking of herpetology, let's end with a happy article about a rainbow toad that's been rediscovered after it was thought to be extinct :)



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