Showing posts with label video. Show all posts
Showing posts with label video. Show all posts

Tuesday, October 27, 2015

The study of the behavior of the octopus predator

 The study of the behavior of the octopus predator

Having finished the last post with a short discussion of hunting/foraging behavior in the octopus, I figured I should do a lighter post with some fun video examples of cephalopod predatory behavior.

This is a short video of an octopus hunting (I don't know the species) by For the Sea Productions.  The octopus catches a fish, apparently by spreading its web and feeling around.  There's some great color-changing behavior here, too.  It's hard to know how typical this behavior is, though, as it's obviously influenced by the presence of the person filming.

This is a clip from Deep Sea 3D (I think - I haven't seen the IMAX film, but that's what the caption says) showing a visually-provoked attack on a crab.  I believe that the octopus here is a Pacific giant octopus.

Let's not leave out the other cephalopods!  In contrast to octopuses, cuttlefish are primarily visual predators, who shoot out two long tentacles (these are tentacles proper - they are distinct from arms, which octopuses also have) to grab their prey.

This video was made by the California Academy of Sciences, and shows some adorable cuttlefish attacking crabs.  I'm not sure what species they are.  Again, you can see dramatic color changes as the animals become aroused.

This one, also by the CAS, shows a great slow-motion shot of the cuttlefish tentacular strike. 

I'll end with one of my favorite videos of cephalopod predation:

Notice how the octopus turns mostly white and spreads its arms when the cuttlefish (most likely Sepia apama, although I'm not sure) approaches.  This is called the deimatic display, and it's a defensive behavior seen in adult octopuses.

I feel obligated to warn anyone reading this that when you search "octopus eating" or similar strings on youtube, you are much more likely to find videos of people eating octopuses than octopuses eating anything.  : (

Monday, October 26, 2015

Some types of squid

 Some types of squid

Time for a treat!  The last post was about the ecological significance of retinal organization in coastal and oceanic squids.  The study I reviewed used 5 species of squid, and I thought it would be nice to take a moment to get to know the research subjects.



This little guy is commonly known as a Mimika bobtail squid.  E. morsei is benthic (meaning bottom-dwelling,) and forages for crustaceans in sandy and muddy seafloors all around western Asia and Indonesia.



Also known as the bigfin reef squid, S. lessoniana is a coastal squid that is found throughout the South Asian and Australian coastlines.  In this video, we see a group performing courtship rituals and laying eggs.



Also known as the Japanese flying squid, this oceanic squid is an important fishery in the pacific.  I'm not sure where this video clip is from, but they sure are cute!




I could not find a video of this guy, but here's an image (by Michael Vecchione, originally uploaded on www.TOLweb.org.)  The distinctive feature of this squid is the photophores (which look white in this image,) especially the two long ones that run the length of the mantle.



T. rhombus (also called the diamondback squid) is a large squid that is found throughout the world.  This (slightly depressing) video shows two specimens in a tank.  Note the large, muscular fins on either side of the mantle.

Thanks, Youtube, for bringing squids to us all.