So far the members of this super invertebrate population have been awesome, complete with horrific details that would terrify lesser men and women, unlike yourselves. And yet, there’s more. There are still several other members that clearly need to be noticed. There are also many that are cool for what they are, such as the brachiopods and bryozoa, but are not as useful to GMs when trying to find things to introduce to their players. We’re going to be focusing on the ones that a GM can use in a pinch, for now. We can always go back and focus on specific traits that are usable for GMs and players in a number of settings. Oh and the marine arthropods, like lobsters, crabs, shrimps, and sea spiders? Give me another month to put together that article.

Echinoderms

Echinoderms are marine animals found in every level of the sea from intertidal pools to the abyss. Echinoderm means spiny skin, which is apparent on many of the species. Most echinoderms start out life bilaterally symmetrical, although a large portion has a left side that grows and absorbs the right side so they end up with five arms. The echinoderms include most of the stars as well as urchins, cucumbers, sand dollars, and several others.

The echinoderms have among them the sea urchins that pose a threat to humans due to the sharpness of their spines. The spines inflict a painful wound when they penetrate human skin, but are not dangerous. It is not clear if the spines are venomous, unlike the pedicellariae between the spines, which are venomous.

About 50,000 tons of sea urchins are commercially fished each year. The gonads are consumed, particularly in Japan, Peru, Spain, and France. In Japan, the gonads can exact upwards of $450/kg these days, making the urchins more important to export than to consume at home. There they are called sashimi and used raw or in sushi. The taste is described as soft and melting, like a mix of seafood and fruit. The quality depends on the color, which can range from light yellow to bright orange.

Purple sea urchins are big on Mediterranean and Chilean menus, eaten raw with lemon, or used to flavor a variety of cuisines. Green sea urchins are exported to Japan from America. Urchins are known in Maine as “whore’s eggs” and were once a delicacy in the Orkneys. Urchins are also eaten in the West Indies, the Pacific Coast of North America, in New Zealand.

Sea cucumbers have leathery skin and an elongated body. The harvested sea cucumber is called trepang, bêche-de-mer or ablate. Sea cucumbers are considered a delicacy in some countries of Southeast Asia; particularly the (Pineapple) roller Thelenota ananas (susuhan) and the red Halodeima edulis. In these areas the sea cucumbers are dried and the potentially poisonous entrails removed.

Sea cucumbers are also thought to be a medicine of some sort. Known as gamut in Malaysia or teripang in Indonesia, they are believed to have healing properties and extracts are used in creams and oils. A single study found that an intraperitoneal injection of sea cucumber extract iun mice was somewhat effective in high doses (100 mg/kg) against internal pain, but ineffective against externally induced pain. Another study suggested that the sea cucumber contains all the fatty acids necessary to play a potential active role in tissue repair. It also appears that some sea cucumber toxins restrain the growth rate of tumor cells, which has sparked interest from cancer researchers. One sea cucumber species is known to produce a lectin that blocks the development of Plasmodium, which causes malaria and is now used to genetically modify mosquitoes.

A remarkable feature of these animals is the catch collagen that forms their body wall. This can be loosened and tightened at will, and if the animal wants to squeeze through a small gap, it can essentially liquefy its body and pour into the space. To keep itself safe in these crevices and cracks, the sea cucumber hooks up all its collagen fibers to make its body firm again.

Some species of coral-reef sea cucumbers defend themselves by expelling their sticky cuvierian tubules (enlargements of the respiratory tree) to entangle potential predators. When startled, these cucumbers may expel some of them through a tear in the wall of the cloaca in an autotomic process known as evisceration. Replacement tubules grow back in one-and-a-half to five weeks, depending on the species. The release of these tubules can be accompanied by the discharge of a toxic chemical known as holothurin, which has similar properties to soap. This chemical can kill any animal in the vicinity and is one more way in which these sedentary animals can defend themselves

The poisons of sea cucumbers are considered psychoactive, but are not well studied.

In Japan, the Northern Pacific Sea Star is considered a delicacy, said to taste like sea urchin when boiled.

The calcareous shells of echinoderms are used as lime by farmers in areas where limestone is unavailable. Up to 4,000 tons of the animals are used annually for this purpose. This trade is often carried out in conjunction with shellfish farmers, as starfish often eat their shellfish.

Sea urchins and sand dollar skeletons are popular collectibles, as are dried starfish. Crinoids, also known as sea lilies and feather stars, have been known to have their fossilized remains strung together as beads on a necklace.

In 2008 biologists learned that sand dollar larvae clone themselves as a mechanism of self defense. Larvae exposed to mucus from predatory fish respond to the threat by cloning themselves, thus doubling their numbers while effectively halving their size. The smaller larvae are better able to escape detection by fish, but may be more vulnerable to predation by smaller animals such as crustaceans.

A variety of imaginative associations have been made by idle beachcombers who run across the bleached skeletons of dead sand dollars. The tests are sometimes said to represent coins lost by mermaids or the people of Atlantis. Christian missionaries found symbolism in the fivefold radial pattern and dove-shaped internal structures. ‘Aristotle's lantern’ has been discerned in the distinctive perforations of Keyhole sand dollars.

Cool Stuff! Regeneration

The regeneration of lost parts and body organs in sea stars, sea lillys, sea cucumbers, and sea urchins can occur one of two ways. In epimorphosis, stem cells either from a reserve pool or those produced by dedifferentiation form a blastema (mass of cells) and generate new tissues. Some fish and amphibians can also produce blastema to replace a missing organ. Morphallaxis is a form of regeneration involving the movement and remodeling of existing tissues to replace lost parts. Transdifferentiation (when a cell changes in form and cell type) is also known to occur during morphallaxis. In some species of sea star a severed limb can grow into another whole individual and several species of sea star use this parthenogenesis to reproduce.

Game Terms: The concept of monsters and characters regenerating should be touched upon. In cases of monsters and marine critters, having an epimorphic-capable creature can mean that the animal is capable of replacing missing limbs and organs with a store of blastema. However, when it comes to regeneration for animals due to a magic spell or some such, the GM should consider that the spell is causing a morphallaxic event. In other words, cells are being regenerated from other existing tissues transdifferentiating to form the missing limb. Therefore that new limb should be weaker, and the whole individual should have a less-than-ideal body for a while. Maybe they’re infertile for a time or have less fat. They should appear drawn out. By all means, make regeneration possible for a player, but the cells have to come from somewhere.

Sea cumbers can break their own tissues down to become a liquid to travel through tight spots and then repair themselves when ready. Any monster could use this trait. Another awesome mechanism from these critters is the sand dollar cloning defense. Give the characters a handful of critters to threaten. Suddenly, they have double the critters and they’re harder to hit.

Parazoa

Sponges are unique in the animal world because they do not have a symmetrical shape and they do not have tissues, although they do have differentiated cells that will migrate within the body to perform functions. There are both freshwater and marine varieties, although the ocean versions are much more useful to humans.

Although many sponges are hard and brittle, a few species have entirely soft fibrous skeletons with no hard elements. These have been used by humans over thousands of years for several purposes, such as padding and as cleaning tools. By the 1950s, though, the sponges had been overfished so heavily that the industry almost collapsed. Most sponges today are synthetic.

Early Europeans used soft sponges for many purposes, including padding for helmets, portable drinking utensils and municipal water filters. Until the invention of synthetic sponges, they were cleaning tools, applicators for paints and glazes, and contraceptives. Even dolphins have found a use for them, and have been observed putting sponges on their noses to protect them while foraging.

Nowadays, sponges are being researched as possible sources of medicines for treating a wide range of diseases.

Game Terms: The characters likely have helmets with sponge padding, and could be called on a sponge-collecting expedition in times of war. A city could deem appropriate punishment as collecting sponges for the local water filters. Sponges will be seen in any well-designed inns or brothels, or used in monasteries for painting and designs.

Ctenophora

The largest animals that swim using cilia, the comb jellies are the Lovecraftian beauties of the underwater world. The “comb” in their name comes from the lining up of cilia in a long straight row, like a hair comb. They are all carnivores, eating anything they can fit into their mouths. They are very similar to actual jellyfish but have colloblastic cells that squirt a glue-like substance on prey to capture them. Although most are small, there are comb jellies that can get up to 1.5 meters in size.

They have no brain or nervous system, but instead operate on a “nerve net;” a cobweb of nerves that form a ring around the mouth and becomes dense near important structures. Most of these creatures are transparent, although some deep down can pick up pigmentation, and many are bioluminescent.

Game Terms: Okay, so technically, these creatures are not very useful to sentient beings, but they’re cool. So we make them useful. Being very large, transparent, and carnivorous can lead to some disturbing imagery at the bottom of the ocean. Skeletons waving their arms inside these creatures and they mosey along is certainly a great way to introduce the. They can emit a glue-like substance that captures prey and binds them up. This is a great trap for players, especially in water, and should be kept aside for the GM to use. Despite not having a brain, their neural nets could be a great way to provide the creatures with a sentience unlike the characters, and then make them aliens or interdimensional travelers.

Cnidaria

Yes, this is a big one, with over 9000 species, all of which are aquatic and most living in seawater. These creatures are special because of their cnidocytes—cells that are used for capturing prey. Most are carnivores, but many obtain at least some of their nutrition through algae, and some are parasitic. Others, such as the stalked jellyfish, don’t really affect man much. Well be focusing on the ones that make characters’ lives interesting.

Anthozoa: Almost completely sessile creatures, but some of the most important in the world. Includes hard corals, soft corals, sea anemones, and sea pens. Hard corals typically live in compact colonies and secrete calcium carbonate to form the reefs that inhabit tropical oceans. Coral reefs are important for protecting shorelines as sources of abundant fish. Coral may be medicinal and the skeletons are commonly used for bone grafting or living bone implants. Coral has often been used as jewelry. Ancient coral reefs now on land once provided lime for building blocks. Sea Anemones

Scyphozoa: Jellies! Yay! As small as 2 cm to 2 meters across, the true jellyfish are legion in the oceans of the world. Very few are harvested as food, but there are some, mostly Rhizostomes eaten in Southeast Asia and cannonball jellyfish in the United States. In Asia the process is carried out by a Jellyfish Master. As established in the poisonous animal article of this column, jellyfish stings are usually nonfatal but suck and can cause anaphylaxis.

Cool Stuff! The Jellyfish Master

The jellyfish master prepares the jellyfish in a 20- to 40-day multi-phase procedure. The gonads and mucous membranes are removed first, then the umbrella and oral arms are treated with a mixture of table salt and alum, and compressed. Processing reduces liquefaction, off-odors, and the growth of spoilage organisms, and makes the jellyfish drier and more acidic, producing a “crunchy and crispy texture.” Freshly processed jellyfish has a white, creamy color and turns yellow or brown during prolonged storage.

Cool Stuff! A Jellied Ocean

Evidence in recent years shows that the population of jellyfish has swelled as a result of overfishing their predators. This has allowed jellyfish to proliferate to the extent that they adversely affect humanity by interfering with public systems and harming swimmers. Jellyfish blooms cause problems for mankind. The most obvious are stings to humans (sometimes deadly), and causing coastal tourism to decline. Other problems include destroying fish nets, poisoning or crushing captured fish, and consuming fish eggs and young fish.

But the overabundance of jellyfish can actually shut down humanity. By clogging cooling equipment en masse, jellyfish have disabled power plants in several countries, including a cascading blackout in the Philippines in 1999 as well as in the Diablo Canyon Power Plant in California in 2010. Clogging also causes many problems including stoppage of nuclear power plants and desalination plants, as well as clogging engines of ships.

Cubozoa: Box Jellies! Boo. The box jellyfish are cubed-shaped and many have extremely killer venom. They’re faster too, moving upwards of 6 meters a minute. They have more developed nervous systems and real eyes along with the lesser developed eyes of the other jellyfish. In other words, they know exactly what they’re doing and are known to attack their prey rather than drift along. Deaths are known to occur regularly with the cubizoa, mostly children due to small body mass, but most stings are not fatal.

Hydrozoa: All the freshwater members of this family, such as the hydra, the freshwater jellyfish, and the colonial swimmers, like the Portuguese Man o’ War. Hydra are especially important to scientists in that the not only undergo regeneration, but they do not seem to die of old age. The freshwater jellyfish are usually seen globally in standing water or slow rivers, such as the Tennessee River.

Cool Stuff! The Systemic Organism

There are hive-minds, and then there are the members of the hydrozoa that make colonial organisms, such as the Man o’ War. These creatures are not one organism but many individuals that are highly specialized and attached and integrated with each other to the extent they are incapable of individual survival. These individuals form polyps to satisfy the colony’s needs. Most polyps are focused on feeding. The man o’ war, for example, is made up of four types of polyps: the sail, the stingers, the gonads (all the individuals are usually male or female in a given colony, and not mixed), and the feeding mechanism. The stingers are usually ten meters long but can reach 50 meters below the surface, and are responsible for up to 10,000 human stings in Australia yearly Although vinegar is best for stings of jellyfish, it is horrible for man o’ war stings, causing hemorrhaging (saltwater and heat best)

Game Terms: By all means, shut down an entire harbor with a bay full of jellyfish. Blow up a nuclear power plant with them. Even better, fill a lake with them and then make the characters have to cross the lake. For sailing and fishing, reefs are where the action is at and most can take out a boat in minutes. Use the concept of the hydra to create immortal creatures. This could even be used in a futuristic setting where immortality is possible. If you’re going to create a hive-minded creature, forget the bees and ants and go for the polyped colonies of the marine world.

Spoon Worms

A member of the Annelids, the echiura or spoon worms are marine worm-shaped, worm-colored worms that grow to be dinner in several Asian cuisines, such as China, Japan, and most certainly Korea. A green variety is being studied because the greenness of its skin makes up a biocide, killing bacteria, larvae, and red blood cells.

Game Terms: Hey, a new bad sci-fi movie: ECHIURA! The arm-length green worms decimate human populations everywhere by forcing themselves into people’s orifices and then exuding greenness. Dinner is served….

Tunicates

Also called sea squirts, these members of the spinal cord family are marine critters that are considered simple enough to be in this group of invertebrates rather than in with their closely related vertebrate cousins. Tunicates are useful to humans in that they contain chemical compounds that are medicinally important, including didemnins, which are effective as antivirals and immunosuppressants, and aplidine and trabectedin, effective against various types of cancer. Various members are used as food, such as the sea pineapple cultivated in Japan and Korea, the figue de mer and limone di mer eaten in the Mediterranean, the piure used in Chile, and the cunjevoi in Australia.

Game Terms: Well, the whole cure for cancer could be discovered in one of these critters and the various countries’ superpowers race to get it. The fate of the entire ocean rests on who exploits these poor little unassuming sea squirts. It is certainly a superhero concept if I ever saw one.

Next Month

Covered a lot of ground this month. In fact, only one group is missing from this illustrious mix of strangeness from the depths: Sea Arthropods! And that will be the last marine focus of this column, for December.