"If we and the rest of the backboned animals were to disappear overnight, the rest of the world would get on pretty well. But if the invertebrates were to disappear, the land's ecosystems would collapse."
David Attenborough

Tuesday, February 22, 2011

Molluscivores- More Death from the Skies: Snail kite in action

Here is a nice video clip of a Snail Kite demolishing an Pomacea (Apple Snail). Watch that beak get to work on winkling out the flesh form the shell.

Read more about these birds and their prey at this MolluscPOW post from December last year.

Wednesday, February 16, 2011

Molluscan Planktonic: Sea Angels and Sea Butterflies

Sea angels are nudibranchs, Sea Butterflies are pterapods. Both live in the plankton layer in the open oceans and both are breath-takingly beautiful. Enjoy.

Thursday, February 10, 2011

Mollusc Giants Part 4- Colossal Squid

Even bigger than the 'giant squid' Architeuthis, the Colossal Squid Mesonychoteuthis hamiltoni is the current title holder for biggest mollusc (and invertebrate) on Earth. The biggest specimen was 10m long and about 500kg in weight but its thought this was a sub-adult animal so the final maximum could be much more. Its beak was significantly smaller than many found in sperm whale stomachs indicating that there are some real monsters down there waiting to be found. 
More cool stuff to come on Sperm Whales and Giant Squid in future posts- I promise!

Mosaic art + marine molluscs= genius!

I am a closet mosaic fan, so when I chanced upon this seashell mosaic masterpiece recently in Panjim, Goa it was a magic moment.
Incidentally, the food was good, but not as good as the mosaic!

Monday, February 7, 2011

Stalkers of the Blue Fleet. Part 1: Glaucilla marginata

Combing the newly-cast strandline on a storm-battered beach is possibly the most fun a nature fanatic can have on their own. NSW central coast this Christmas was especially good. The storms came one after another all week and I spent many an hour strolling the glistening sands of South West Rock's Main Beach. In past seasons this beach has thrown up many gems, once a magnificent Nautilus came bobbing ashore as I watched, but thats a story for another day.
On the best day of the week for wrecked sealife, I noticed tiny striped splodges mixed with the blue tentacles and wobbly bladders of the abundant Man'O'War jellyfish Physalia phisalis. (OK, OK, in Australia they are called Bluebottles, and they are not actually jellyfish but properly a zooid Siphonophore- happy now?) I happened to have a plastic tub with me (as you do). I filled it with seawater and popped one of the droopy splooges in. On hitting the water it sprung back to life- a shining perfect little nudibranch called Glaucilla marginata. In a flurry of excitement I took dozens of photos. These are special molluscs indeed- ruthless pelagic predators which stalk the wandering 'blue fleet' of Man'O'Wars. They are not the only molluscan hunters of these drifting stingers and further along the beach I found a couple of examples, but I'll save those for future posts.
The blue fleet is a remarkable community of creatures. Normally they ply their trade far offshore but as the Physalia blindly drift where the wind blows and all the others follow the whole lot are prone to being blown ashore.
Like many pelagic sea creatures Glaucilla and its close relative Glaucus are not restricted to any one sea area- they occur almost everywhere the sea is the right temperature for them. They float upside down (the photo here is of their belly) close to the surface tension and simply bump into their prey as they drift. They can be mobile if they find themselves stuck- flexing and wriggling in that sea-slug sort of way until free. The blue colour is said to be the accumulated venom from the zooid tentacles. This obviously works as a predation deterrent- beachcombing Silver Gulls carefully avoid them.
So, a carnivorous sea slug which sails the seven seas hunting a dangerous prey- surely that has to be the weirdest thing I found on the beach that day. Not so...

Thursday, February 3, 2011

Wednesday, February 2, 2011

Molluscivores Part 2: Snail-eating Snakes!

Time for another mollusc-murderer. This week its video of the remarkable snake Pareas iwasakii. These snakes are adapted to hunt meaty forest snails such as this Satsuma mercatoria. The relationship between this predator and prey neatly illustrates the role predators and prey role in shaping each other's evolution. A truly cool reptile.