• Colossal squid caught

    Once again, I’m coming late to the party on this one. It seems that fisherman in Antarctica’s Ross Sea caught the largest specimen of Colossal squid (Mesonychoteuthis hamiltoni) to date.Most folks are aware of Architeuthis dux, the giant squid.Few folks are aware of the fact that while A.dux is the longest, it’s actually M.hamiltoni that is the largest. Judging from sucker marks found on sperm whales, as well as actual remnants found in sperm whale stomachs, these guys appear to be much nastier than your garden variety giant squid.

    It’s too bad that this one was found dead already. Hopefully we’ll be able to nab some footage of these living giants, one day. Till then, we’ll have to make due with dredging up remnants of these awesome beasts.

    ~Jura


  • Supersize crocs on PBS

    Last week the long running PBS series, Nature, showed an episode entitled: “Supersize Crocs”. The premise was to follow croc conservationist, Rom Whitaker as he attempted to see if any 20+ foot crocodiles survive today.

    Unfortunately, much like the Discovery Channel’s “In Search of the Giant Squid” documentary, the results garnered from this doc were inconclusive at best. By the end of the show, the largest croc actually found, was 18ft long. Compared to the late, great Steve Irwin’s attempts at finding giant crocs, it would appear that Whitaker was short by 1 foot. There was some allusion to a 20 foot beast that was seen briefly before it ran into the water. Unfortunately Whitaker could only give a guestimate of its size based of its slide print (which was not all that clear).

    Overall, the documentary made for a nice hour long diversion. There was a lot of crocodile measuring, and some unecessary CGI used to explain crocodylian anatomy. It also featured Croc biologist, Adam Britton, though only for about 10 seconds.

    There were, however, some problems with the program that bugged me.

    First, was the purported maximum size. Whitaker wanted to find a 20 ft croc. During the program he ran into a person who said that he had seen a 22ft individual. He said that this was 2ft longer than the longest individual ever recorded. The problem with this is that there have been reports of saltwater crocodiles (Crocodylus porosus) reaching sizes of 23 ft. While not all these reports may be valid, there are enough credible ones to suggest that they once could reach this size (Ross, and Magnusson, 1989).

    My second qualm comes from Whitaker’s statement that crocodiles grow slowly. In the documentary, Whitaker states that the largest crocodiles (the 20+ footers) would have taken 80 years to reach that size. That is a completely unrealistic statement. Most crocodylians studied to date, tend to take between 10-15 years to reach sexual maturity. At this point they are often very close to their maximum size. From this point on, growth slows substantially (though never completely stops). Large crocodiles might live to 80 years old (some may be centennial), but they don’t take 80 years to get there.
    My final problem with the program was that it continues to promote the myth that crocodylians have remained unchanged for over 200 million years. Crocodylians (i.e. Eusuchia) weren’t even around 200 million years ago. In fact, true crocodiles are a fairly recent group, having evolved around 80 million years ago (something that the Nature website gets correct, but the actual documentary does not). They are but one branch of a highly successful group of animals called crocodyliformes; which in turn are a branch of the highly successful crocodylomorphs. Finally, all are members of the Dinosaurian sister group: Crurotarsi, or Pseudosuchia (for those who would like to continue the croc naming trend).

    The only reason why crocodiles always get lumped into the “living fossil” category, is because the bodyplan that they do have, happens to have been a popular bodyplan for the past 200 + million years. Crocodylians are just the latest group to use it. Before them, there were pholidosaurs, and way before all that, we had phytosaurs.

    Calling crocs living fossils, is doing a disservice to their lineage. Just among the Crocodylia, we had such out there animals as the land dwelling, panzercroc Pristichampsus, and the weird Australian mekosuchines (e.g. Quinkana, Mekosuchus, Trilophosuchus, to name a few).

    Not to mention strange behemoths such as the “duck billed” Purussaurus.

    Regardless, the point is that crocs are way more diverse than they are ever given credit for.

    Overall, I’d say the best part of the entire documentary would be the scenes of freshwater crocs (C.johnstoni) galloping into the water.

    Oh, and the only reason I’m bringing this up now is because I just saw it last night.

    ~Jura


    Refs:Ross, C.A. and Magnusson, W.E. 1989. “Living Crocodilians” in Crocodiles and Alligators. Ross, C.A. ed. Facts on File pg: 68


  • Virgin Dragons and Fossil Sharks

    This is more of a catch-up post than anything else. A few months back, it was announced that Flora, a Komodo dragon had laid fertile eggs even though she had never been with a male dragon. Now, just last week, it was announced that the eggs hatched.

    The overall story is interesting, for it shows that parthenogenesis is more common in reptiles than previously thought (the original suggestion for this came from a timber rattlesnake [Crotalus horridus] that also gave birth to young without the aid of a male). Surprisingly the story doesn’t mention the sex of the babies. Reptiles that have genetic sex determination, rely on ZW and ZZ chromosomes. Unlike mammals, though, the heterogametic sex is female (i.e. they have the ZW chromosomes). This means that in a parthenogenic clutch of eggs, the choice of chromosomes is either ZZ (male), or WW (infertile), but never ZW. As such, all parthenogenic hatchling reptiles and birds, are male (there are exceptions for certain all parthenogenic species, but they create all females by doubling [tripling] their chromosomes). This has implications for colonization. A parthenogenic female can give birth to male offspring, which can then mate back to the mother (nasty, I know), and produce a more even sex ratio and a more stable blood line. Perhaps it’s because males are the heterogametic sex in mammals, that parthenogenesis is not found in this group. A female that can only give birth to other females, is far less likely to make a lasting line in new environments.

    The second bit of interesting news, comes from Japan, where scientists report the discovery of a rare ancient shark. The frilled shark (Chlamydoselachus anguineus) is a rare site, as it usually lives hundreds of meters below the surface. The video that Reuters (and other news outlets) has, is stunning to watch. The shark almost looks like an animatronic piece of Hollywood fiction. It was unfortunate that this female didn’t survive. Hopefully we will be able to capture footage of healthier individuals in the future.

    That’s it for now.

    ~Jura


  • New Site Design

    Well the Reptipage has been up for almost 9 years now. Sadly, about 5 of those years were spent in stasis. Due to lack of time on my part, as well as lack of resources (both academically and developer wise), my site quickly became stagnantt. I’ve finally decided to change that, and the first step is to drag my site kicking and screaming, into the land of Web 2.0.

    Hence, the blog.

    Personally, I hate that term. Before weblogs were known as blogs, they were originally just called: “What’s New.” It was a simple phrase that was illustrative of what one would expect (i.e. new developments on the site). This blog is going to follow more along these lines.

    That said, I also intend to use this space to talk about the latest news stories involving natural history. Especially the natural history of reptiles and their ilk. For despite 9 years of service online, the web is still remarkably deficient in reptile information (with the exception of the ever growing field of herpetoculture).

    Since blogs allow for user feedback, I welcome responses. Over the years I’ve also received various e-mail questions, but have rarely had the time to answer them. I hope that by offering the option for instant feedback here, I’ll be able to answer more questions effectively. If I don’t, there’s a good chance that someone else who is reading the comments, can lend their 2 cents in.

    Expect a fair amount of changes over the next month, or two. Hopefully I’ll be able to finally execute some of the grander ideas that I’ve had for the site. All the previous pages are still available. Just use the links on the side bar to get to where you want to go.
    Stay tuned.

    ~Jura