Gaudy Gastropods

My garden slugs are slimy, of course, plain and rather dull...

but their marine relatives are a different story (to read more about land slugs click here).  Nudibranchs are marine mollusks - invertebrates that comprise almost 25% of all known marine species - and one of the most colorful and strange-looking species on the planet.  They are also known as sea slugs.  There are more than 3,000 members of this group and are found in all oceans, but most frequently in the Indian and Pacific oceans.  They are found at all depths, but the most striking ones are generally found in warmer, shallower waters.  They are bilaterally symmetrical and vary in size from less than an inch to around 2 feet long.   They are hermaphrodites - able to act as either males or females in the reproductive process - and carnivorous feeding on sponges, hydrozoans (small creatures related to jellyfish and corals), sea squirts, other sea slugs, and even their own species.  They shed their shell after the larval stage (hence the name 'nude'ibranchs) and have head tentacles that are sensitive to touch, taste, and smell.  Like many colorful species, their vivid hues and color patterns warn predators that they are poisonous or just plain taste icky!  They use toxins of the prey they eat to defend themselves against their own predators.  (As a result, some can deliver a paintful sting to humans.)  Nudibranchs come in many forms; some have ruffles, fans and feathers like they're all dressed up for a ball.  But those fans and feathers are not just decorative; some of their 'decorations' are actually gills.  And the 'ruffles' help propel them through the water and are used as a 'floatation device'.  Like land slugs, sea slugs use their muscular foot to propel themselves on underwater surfaces, although in a few cases like the Glaucus atlanticus, also known as the blue glaucus, it simply floats on the surface of the water.  Obviously I can't show all 3,000 species in one post, so here are just a few pictures of ones that I liked best.  (And no, I haven't actually seen pics of all 3,000!)



Pteraeolidia ianthina, sometimes called the blue dragon

Source:  Wikipedia

Orange Peel Doris   Source:  Wikipedia

Frilled nudibranch (only found off South Africa)   Source:  Wikipedia

Berghia coerulescens   Source:  Wikipedia

Hermissenda crassicornis   Source:  Wikipedia

 Nembrotha milleri   Source:  Wikipedia

 Dendronotus iris   Source:  Wikipedia

Loch's Chromodoris   Source:  Wikipedia

 Marionia blainvillea    Source:  Wikipedia

Nembrotha cristata   Source:  Wikipedia

Tritoniopsis elegans  Source:  Wikipedia

Chromodoris annae   Source:  Wikipedia

Spanish shawl  Source:  Wikipedia

Sea clown triopha    Source:  Wikipedia

 

Spanish dancer  Source:  Wikipedia  (Click here for a short video)

 

And my absolute favorite, the variable neon slug or Nembrotha kubaryana.  It's so fabulous I thought it deserved TWO photos!  In the last photo, doesn't it look like it's wearing ruffled velvet?

 

 Source:  Wikipedia

Source:  Wikipedia

 

Hope you enjoyed seeing some of these wonderful creatures.  There are other sea slugs that not nudibranchs, but part of the opisthobranch family and I'll talk about them in my next post.

Click here and here to see videos and learn more about nudibranchs.