I swear I'll get in the habit this time... also, bobtail squid!

I haven't had a 'real' update in forever, especially since my last several posts were actually articles written for Tigra Scientifica or Decipher. But, since the idea of having a lab blog came up in grad school interviews, I REALLY need to get back in the groove. For a while I had a good pattern for the personal blog, but the science one never launched... time to fix that.

In the last two years, I've graduated from Clemson, moved back west, spent a year at home and am now about to pursue a graduate degree at Oregon State University with zoology (unspecified for now because while I was accepted as a masters student, I am leaning strongly towards switching to the PhD program. A huge helping of impostor syndrome is keeping me from making that decision until after the first quarter, however).

It's funny, because I considered Oregon State when looking for undergrad schools partly because of the Zoology department. High school me wasn't able to articulate that zoology isn't about zoos, though, so when I applied I did so as a pre-bioengineering, hah. That would've been a very different path for sure.

But enough housekeeping! Let's dig into some science.

International Cephalopod Awareness Days are coming up in a couple weeks, and while the tumblr doesn't look like it's been updated since last year, I've been looking forward to this more than Shark Week. While bobtail squid would probably be more of a 10-10 post, they're in a completely different order than typical squid (Sepiolida vs. Teuthida)

via Nick Hobgood on Wikimedia Commons

Besides being adorable, they're also symbionts with bioluminescent bacteria.




There's actually several labs out there working with Euprymna scolopes and Vibrio fisheri interactions- one in microbiology at UGA has done some sequencing and a University of Wisconsin-Madison lab has interesting ideas about the bacteria as an influence on the squid's circadian clock, which has wonderfully interesting applications for microbiome research.

Actually, symbiosis in general is pretty cool. :-)

The New Fisheye View: The Sea in HD

This appeared in the Spring 2012 edition of Tigra Scientifica for BioSc 494: Popular Science Journalism.

The world as we see it is full of a bewildering number of hues, enhancing life with a spectacular array of shades. What if there’s another layer of information and detail we can’t sense, though? Humans only see a small portion of the electromagnetic spectrum. Unlike us, some animals see polarized light, which enhances their world even more, analogous to adding color to a black and white image. In a study at the University of Bristol published in Current Biology February 2012, Dr. Shelby Temple, Professor Justin Temple, and collaborators have discovered that cuttlefish have the most acute polarized vision of any animal observed so far.

            What makes polarized light different? Polarized light rays vibrate in one plane as opposed to multiple planes like other light rays. For humans, polarized light usually means reducing glare with sunglasses or watching a movie in 3D, some organisms have greater purposes for it. In other animals, polarized light is used for navigation and orientation. In 2006, Savannah sparrows were found to use polarized light to determine where north and south is more accurately. The researchers believe that animals may use polarized light in predator/prey detection and in signaling and communication, especially in cephalopods like octopus, squid, and cuttlefish. The cuttlefish species studied here cannot see what humans consider to be visible color wavelengths, so polarized may substitute as a method of seeing the details of its world.

            So, how do you give a cuttlefish an eye exam? To examine the sensitivity of cuttlefish vision, the researchers took LCD computer monitors and removed the polarizing filter. A video was played for the cuttlefish in which an expanding circle mimicked the appearance of a looming predator.  These circles were shown at different levels of grayscale and different angles of light so they were only visible to creatures with polarized sensitivity. When they detected the movement, cuttlefish responded by changing skin patterns. Cuttlefish responded to differences as small as one degree of polarization, significantly more precise than previous species like octopus and crayfish examined which responded to differences of 10 to 20 degrees. 

The researchers also analyzed low- and high-resolution sight by examining images of aquatic life. Because we can’t see differences in polarization, false colors were substituted, and the team found that while animals disappeared into the background in the low-resolution images, they were visible in the high-resolution analysis. This leads Professor Temple to note that camouflage in the polarization dimension has not been investigated and could be the reason why cuttlefish and other predators may have developed high sensitivity to polarized light. The mesmerizingly detailed patterns cuttlefish flash on their skin may also use polarization for detailed signaling and communication, but more research is needed. This study is a great beginning to investigation of alternative ways to sense the world and could be applicable for finding out how animals and plants signal each other- imagine if there were giant ‘DO NOT EAT ME; I’M POISONOUS’ signs we’re not even aware of in everyday life. Perhaps eventually humans too can tap into this other level of vision for navigation and communication purposes. 

 

http://www.sciencedirect.com/science/article/pii/S0960982212000115

Stuck on You: Tiny Squid makes Two Kinds of Glue

Like the previous article, I had difficulty trying to find an application that college students could appreciate. As previously mentioned, this was part of BioSc 494: Popular Science Journalism and appeared in the Fall 2011 issue of Tigra Scientifica which can be downloaded here.

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While other mollusks like snails and mussels often secrete sticky ooze, cephalopods like octopus and squid generally aren’t known for chemical adhesion. Hoever, members of one squid family Idiosepiidae, are identified by their sticky secretion organ. Idiosepius squid can be smaller than your pinky fingernail and glue themselves to seaweed in order to hide from predators. They can then quickly unstuck themselves for a speedy getaway. In a study published in the Journal of Marine Biological Association of the United Kingdom, Mag. Norbert Cyran and his team from the University of Vienna investigated Idiosepius’ adhesive organ at a microscopic level for the first time and found that the diminutive squid makes two different types of glue.

Many kinds of chemical adhesion are found in nature. Barnacles are infamous for the strength of their attachment to any surface, gripping on everything from boat hulls to living whales. Spiders use natural adhesives to construct intricate webs. These organisms usually use mixtures of proteins and carbohydrates to make their glue. Humans have tapped into this, by boiling animal bones, tendons, and skin to make the animal glue used in stringed instruments and deriving shellac from a species of beetle in India.

            Samples of the squid skin were prepared and examined under electron microscopes. The adhesive organ was also stained and sliced for 3-D analysis in a computer. The outer skin layer consists of two cell layers made up of six different cell types, which correspond to structures initially described in 1921. Three of the different cell types are specifically restricted to the adhesive organ and are likely linked to glue production. One type of cell was evenly spread throughout the organ, and the other two clustered together. Both the evenly distributed cells and the clustered cells use a similar secretion pathway, but based on where the two types of cells are in the skin Cyran and colleagues determined that these are two different types of secretions. Cyran proposed two different models: in the first, the two different types function as a duo-gland system where one secretion glues the squid to a surface and the other secretion unsticks, and in the second model both cell groupings produce the same type of glue. The researchers suggest more biochemical research is necessary to truly unlock the sticking mechanism.

Further research into Idiosepius’ glue methods could be promising. Bioadhesives could be used in the medical field where needed, as the body might be less likely to reject a biologically created adhesive than a synthetic one- a possible technology for stitches.   Biomimicry, or taking ideas from structures and processes in nature for human use, can lead to novel applications. Barnacles have been studied for their incredibly strong glue. Idiosepius’ temporary glue could have equally useful applications. Once the reaction is figured out, the glue-making method can be applied elsewhere. For now, though, Idiosepius’ exact glue recipe remains a mystery.

Ultrastructural characterization of the adhesive organ of Idiosepius biserialis and Idiosepius pygmaeus (Mollusca: Cephalopoda)
Norbert Cyran, Waltraud Klepal and Janek von Byern (2011) 
Journal of the Marine Biological Association of the United Kingdom, http://journals.cambridge.org/action/displayJournal?jid=MBI&volumeId=91&bVolume=y - loc91, Volume 91, Issue 07 , November 2011 pp 1499-1510 
http://journals.cambridge.org/abstract_S002531541100021X