Deep-sea giant squid (Architeuthis) remain one of the ocean’s most charismatic zoological mysteries. While there are plenty of specimens in museums around the world, little is known about their behaviour. Only recently have fleeting glimpses been captured of these creatures in their natural habitat; a 2005 paper (http://rspb.royalsocietypublishing.org/content/272/1581/2583.full) in Proceedings of the Royal Society B described the first ever wild observations of a live giant squid. The author’s photographs showed a huge squid actively hunting at 900m below the surface and they even managed to recover a tentacle that snagged on the bait line (see panels ‘e’ and ‘f’ in the figure).
We also know about the predator-prey interaction between sperm whales and giant squid from the sharp-sucker scars often seen on whale skin and stomach contents (squid beaks are indigestible making them a useful clue to the diet of sperm whales).
Earlier this year, footage taken by a manned submersible was broadcast showing a giant squid 1000m deep in the North Pacific. The footage was captured using near-infrared light (using invisible to humans and squid) since giant squid avoid the bright white light used in conventional filming- perhaps something to do with those enormous eyes? (have a look here: http://www.eeb.yale.edu/ugrad/eeb171pdfs/sa-246-1982.pdf)
See clips from the video at http://www.youtube.com/watch?v=1KN5N1QDaRQ
(picture credit: NHK/NEP/Discovery Channel via Reuters)
As an aside, it’s worth taking a look at this report on the unusual mating behaviour of giant squid – it turns out that male squid giant inject spermatophores directly into wounds that they form on the tentacles of a female:
More recently a somewhat alarming article showed how male squid overcome the challenges of mating at great depths using a ‘super squid sex organ’ – see the long white tubular structure in the picture below.
The amazing “Jurassic Coast” in Dorset/Devon has thrown up another fantastic fossil – the skull of a massive pliosaur, which would have been perhaps 15m long. To be honest, the fossil isn’t much to look at (a load of rock), but it’s a pretty impressive find. Pliosaurs, in case you don’t know, were short-necked marine reptiles. Together with their relatives the plesioaurs (with long-necks, which look like the Loch Ness Monster) they ruled in the seas up until shortly before the end of the Cretaceous. There’s a great fossil plesiosaur and a model in the Manchester Museum. And no, they were not dinosaurs, which neither flew nor swam.
BBC page, includes video (probably not visible outside UK)
Adam Smith’s fantastic Plesiosaur site
Adam Smith podcast on is Nessie a Plesiosaur and other (more serious) things:
Dealing with wild animals is difficult. This video tells the amusing/sad story of an arctic seal, which was found – very lost – off the coast of Africa, was brought to the UK, fed, then eventually released from the north coast of Scotland, pointed in the right direction. What happened next?
Filed under Oceans, Videos
Parrotfish are major grazers of the algae that grow on coral reefs. Protecting them from over-fishing may be decisive for the survival of reefs in the Caribbean. Sea urchins can also do the trick. That’s the take-home message of a Nature article, most of which consists are rather hard to follow mathematical modelling – ecology is not all (or even at all) about tree hugging! There are some very tough sums involved!
BBC article (includes loadsavideos of parrotfish doing stuff); Nature article (not for the faint-hearted or those without a subscription).
There are no insects that spend their whole life cycle under the surface of the sea, and very few that spend even part of their life on or in the sea. Why not? This student-built website takes you through the various hypotheses (salinity, competitive exclusion etc) and provides you with lots of thought-provoking ideas. NB You can’t jump to the end and get “the answer”, for two reasons – a) there isn’t one and b) you have to collect the letters of a password by going through each hypothesis!
Filed under Insects, Oceans
Super pictures of life on coral reef in Australia.
Filed under Fish, Images, Oceans
Go back in time 510 Myr, shortly before a mudslide trapped and preserved an amazing array of soft-bodied fauna in a shallow sea in what is now called the Burgess Shale. This video – an extract from a 5-minute long show from the Field Museum in Chicago – shows some of the key bizarre organisms (including Wiwixia, Marella and Anomalocaris) that are characteristic of the Cambrian Explosion. The video is quite long and is in Quicktime format. As the students who have seen it in the Evolution of Animals lectures will know, it’s well worth the wait!