Creature Feature: Scenella.

Hello, and welcome to another entry set in the Cambrian shallow seas. Before we start today's entry, we would like to remind you all that this blog does not condone the use of psychoactive drugs. That means that everything we post from the Cambrian Period definitely existed. We're sorry if this disappoints any of you.

That said, mollusks with hats.

 

Scenella was one of several strange mollusks in the shallow Cambrian seas. It has been found in Asia, Antarctica, Europe, and North America. There have also been some theories that it was related to floating hydrozoans like the Portuguese man-o'-war, although several things say it's an ancient mollusk. 

Scenella were small, shelled creatures. They often hung around in groups if the Burgess Shale is any indication. They were probably eaten by larger, faster things like Opabinia and Ottonia - both of which are trippy in their own right. Scenella themselves probably ate algae and small bits of debris. In other words, they were the zebra mussels of their time.



Despite probably bearing many similarities to small, modern mollusks, Scenella remains strange. That hat-like shell makes it look like an ancient limpet (which probably could use an entry in and of itself), which would line up with it being a mollusk rather than an oddly-developed hydrozoan. An affinity to gastropods (snails and slugs) is likely due to how the muscles were attached. Show me the evidence for these guys being hydrozoans and we will gladly hear you out.

Remember, kids, seeing things out of your nightmares and acid trips on this blog is A-OK. It's all right in museums and labs, too. If, however, you are walking along and see a troupe of hat-wearing mollusks crossing the road, you may wish to see a shrink.

OMG SHINY! - Pearls.

Speaking of precious, colorless shiny things...



Diamonds and pearls are often placed alongside each other even though they are hardly related stones. They are both shiny, colorless, rare gems that can be used to denote something valuable. Despite this parallel usage, pearls are very different from diamonds in a number of ways.


That did not stop Nintendo.

A pearl is formed when an irritant - an overlarge particle, parasite, something organic and annoying - enters the shell of a bivalve (usually some type of oyster). The mantle of the mollusk releases a mixture of calcium carbonates and conchiolin (three guesses where that name came from) to envelop the irritant in shiny nacre (which makes up mother-of-pearl). When you get a pearl, it's almost like receiving a particularly pretty mollusk scab.

There are three types of pearls to be aware of: Cultured, natural, and, of course, fakes. The differences between natural and cultured pearls require either cutting the pearl or sending it to a gemologist to be x-rayed. Natural pearls will show rings akin to a tree's growth rings - layers upon layers of nacre applied upon a pesky parasite - while cultured pearls will be solid in the center.

Fakes can be distinguished by a number of (expensive) testing methods. X-rays and trips to experienced gemologists will work, yes, but far cheaper home testing methods include holding the pearls in sunlight (natural pearls won't match colors and have imperfections) and the rather unreliable method of feeling the gritty nacre in between one's teeth.

There are even more distinctions, such as whether the pearl in question came from a fresh- or saltwater mollusk, as well as different types such as the keshi pearls (cultured, but occur semi-randomly). A really good jeweler will know if a pearl falls under one of these other classifications; if they can name the exact species of mollusk the pearl came from, they deserve a raise.

Natural pearls are indeed rare. The value is determined by factors such as size, iridescence, shape and color. Black pearls are particularly valuable; there is no good way to produce them in a culture, and even with the specific requirements met, something tends to go wrong in the process. In short, nature says no.


Jack Sparrow says yes.

Then there are pearls that are not really pearls by most people's standards. They are formed the same way that real pearls are (that is, by an annoyed mollusk), but usually lack the luster and other desirable properties of gem-quality pearls. Many types of mollusks make "calcareous concretions;" some conches, for example, produce pink 'pearls' of this nature. The most famous of these concretions is the Pearl of Lao Tzu; if that name sounds familiar, it's because this hardened emu dropping pearl came from a giant clam.

It still looks like a turd to me.

Creature Feature: Sea Lizard/Blue Dragon.

Oh, crap. Not ANOTHER thing we have to fear from the ocean!

Actually, this one's relatively harmless. The sea lizard (Glaucus atlanticus) will not eat you unless you are a cnidarian or fellow slug. This creature is not to be a confused with lizard fish; the sea lizard in question here is a small, blue sea slug native to most of the world's oceans.

Sea slugs have been blessed with such a variety of shapes and colors that even perfectly sane people wonder what they're tripping on. For starters, all gastropods are hermaphrodites - they have male and female junk. If that was not trippy enough, name a color; sea slugs come in it. Name a type of locomotion; sea slugs can do it (or at least look like they're doing it). Name a land animal; it probably has a counterpart in sea slugs. All things said, they are AWESOME creatures that I am ashamed for not doing an entry or five on earlier. (I do not know HOW, but Pokemon managed to de-awesome them.)


DUDE I CAN TOUCH THE RAINBOW! IT SMELLS AWESOME!

These particular sea slugs have gills that look like feathery feet or fins alongside their bodies. They swim upside-down; the name 'gastropoda' means 'stomach-foot,' and this thing is walking on its back like something out of a horror movie 24/7.



Now, hold on a second...aren't colorful things usually poisonous? In this case, yes and no; many sea slugs, these guys included, gain toxic attributes from their food. G. atlanticus in particular feeds upon the stinging tentacles of the Portuguese Man o' War (Physalia physalis)- a cnidarian colony (not a jellyfish) known to be deadly to humans. The Glaucus is completely immune to its venom. Like in some caterpillars, the poison in the tentacles gets used for the sea slug's own defense.

Look, but think before you touch. Enjoy the acid.

(By the way, fun fact: The generic name for 'Glaucus' comes from the myth of Glaucus and Scylla. Look it up if you like; Circe's involved!)