Nudibranch (Nothing to do with Naked Chicks....)

I want to keep the unusual animal streak going, but change it up by going to the ocean for our next creature.  The Nudibranch resembles a neon colored slug and can either be smooth or have lots of equally colorful tentacles.  Nudibranch's have undergone detorsion, where their mouth and anus for a long continuous tube.  Torsion is the process that shelled gastropods go through to rotate their mantle and shell 180 degrees to bring it directly above their head.  Due to going through detorsion, Nudibranch's are bilaterally symmetrical.  They have very simple eyes which are typically limited to sensing light and dark.  They breathe through a naked grill that forms branchial plumes in a rosette in their back, where the name Nudibranch likely originated from. 

They are hermaphoditic (containing both sexes) but cannot fertilize themselves.  Hermophoditicism is a common trait in sea animals to increase likely hood of finding a mate.  Think to a Nudibranch every other Nudibranch you meet is a potential partner, instead of being limited to one sex or the other. 

So the big question remains, why did Nudibranch's develop such bright colors?  well it seems Nudibranch's took two alternative approaches, one was to blend in the other to stand out.  Some Nudibranch developed colors and appendages to mimic plants around them, an extreme camouflage.  While other Nudibranch took the opposite approach and developed bright colors to stand out and warn predators that they are poisonous or distasteful.  Some Nudibranch feed on hydroids then store the hydroids' nematocysts (stinging cells), they can travel down their body with out harming the Nudibranch.  They likely do this with a large vacuole surrounding the nematocyst.  There are some Nudibranch's that can produce toxins on their own without dietary aid, there is even a type of Nudibranch that can excrete acid out their skin. 

To sum up, the Nudibranch is more than a colorful sea slug, it is a highly specialized creature showing every color of the rainbow.  That's it for now,
Cass

Outrageous Otters

In honor of some special people in my life who love otters, today's blog post is for them (yes you Mow Wow).  Otters are related to weasels, badgers, and wolverines, quite a list of tough relatives.  There are many types of otter including but not limited to, North American river otter, Sea otter, Eurasian otter, and Giant otter.  Most view otters as adorable critters who frolic in the water...  Otters are actually incredibly tough little guys. (click on the video to watch them take on a crocodile, sorry I couldn't find this minus the ads, but the best part starts at 1:00 minute)
http://www.youtube.com/watch?v=ArhWJts2sg8

Now Sea otters do not have an insulating layer of blubber like other ocean mammals (seals and whales), instead they have very dense fur that traps in air.  They will bob to the surface and blow into their fur to keep it warm.  An otters coat is very dense at 26,000 to 165,000 strands per square centimeter of skin, compare that to humans with 3175 strands per centimeter on their heads.

The Giant otter lives in South America along the Amazon and Panthal rivers.  They live in large colonies lead by a dominant breeding pair.  This otter species is exclusively diurnal, or only active during the day.  Being diurnal indicates that otters have amazing eyesight, in and out of water, and shows they are a sight predator.   Otters on the whole are extremely vocal, with the Giant otter being the most vocal.  Their chirps and barks mean anything from greetings to warnings.  Otters are opportunistic eaters devouring a wide variety of food including fish,  crabs, snakes, and caimen babies.  One commonly eaten fish by Giant otters is even piranha, now that's a tough guy!

Hope you all enjoyed the break from my pet posts, and learned a little more about one of the toughest and cutest critters out there.
Cass