More than half of the seafloor on planet Ectora is covered by reefs – the result of millions of years of growth of tiny polyp animals that fix themselves in place and secrete cups of silicon carbide or other minerals, filtering photosynthetic monocells and other particles from the water. These reefs in turn provide homes and nutrition for numerous mobile animals.
The most prolific reef builder doesn’t make just cups. Clapping worms are highly mobile little worms that swim by means of rows of tiny oars down their sides. They spend most of their waking hours poking out of tiny holes in their castles to catch plankton by “clapping” their hands and drawing it into their mouths. When not feeding or sleeping, they spend time building up castles with secretions from their hands, spreading it over the surface. The mineral-rich mucus hardens after only a few seconds, containing active cells to finish the process before dying. Inside each castle are common living spaces and a complex network of tunnels.
One of the most common polyp animals are the branch tongues, which is a bit of a misnomer since not all of them have branched tongues. Some have multiple ends per tongue, some have multiple tongues per mouth, some have multiple mouths per stomach, some have multiple stomachs per body, and some are colonial organisms of multiple bodies. Many have some combination of all these attributes. At the ends of the tongues are sticky lures to attract different types of swimming prey or sticky hairs to grab floating plankton. Snap traps have yet a different sort of lure. They resemble nooses. The lures of snap traps are not sticky, but will snap shut on anything disturbing the lure in the middle held only by two narrow strings. Once a meal has been caught, the tongue is pulled down into the stomach (where its base is attached) to be digested along with the meal. For those species with more than one tongue end per stomach, the animal will usually wait until seventy percent or more of its tongue ends are full before drawing them all in. It cannot wait too long, however, because there are other animals that might crawl by and try to steal a meal.
The pin traps are one family of branch tongues that take advantage of this. The lures are able to sense what type of prey has bitten into them. When bitten by small prey, the lures merely swell up and secrete glue to hold it there, using the small prey as a lure for larger prey. When bitten or grabbed by large prey, a large number of mineral fibers from deep in the tongue shoot outwards at high velocity, hardening on contact with foreign tissue and sending out offshoots to hold them in place. On signal, the animal will draw its other tongue ends around whatever it has caught, all of them extruding rapidly hardening mineral fibers on contact. It then pulls the prey into its mouth.
Sea scoops are spoon-like or shovel-like animals with jointed exoskeletons that strain seawater for plankton. They make a sweeping motion with their bodies, closing their scoop tight and forcing the water through the screen on the back side. Particles too large to fit through the screen are held and then scraped down the throat before the scoop opens again for another sweep. In this way, the sea scoops sweep back and forth all day while firmly attached in their silicon carbide cups. Sea scoops can be as small as a millimeter long or as large as three meters.
Spoke polyps are small animals with tongues ending in spoked wheels. The tongue captures food particles in its gaps and then retracts into the soft animal, which envelops it and wipes the food particles down the throat.
Umbrella polyps are small animals with appendages shaped like umbrellas. The appendage sweeps food particles inward and upward where it can be grabbed by short tentacles underneath and pulled into the mouth.
Screwcap shells are an incredibly diverse group of animals with hard outer shells. In most species, there are two shells with treads along their meeting edges to allow them to twist tightly shut. When open, the flesh of the animal stretches across the opening between the two shells and the animal extends its gills. The gills not only facilitate gas exchange, but gather food particles as well – although some species do not feed on plankton.
Plankton-feeding tube shells fix one shell to the seafloor early in life and grow it longer while keeping the second shell fairly small. The second shell becomes a screw-on cap at the end of a long tube. Climbing shells have ridges on the outside to help them “walk.” Some swing their shells left and right while others inch forward and back. Hammer shells pivot where the soft animal holds the shells together and uses one of its shells to bludgeon other animals. They usually break open polyp cups or other screwcap shells to eat the insides, although one species has been observed “clapping” a passing false fish between its shells. Crusher shells grab other screwcap shells between its shells where it has teeth and crushes them until they crack open. With so many predators about it is no wonder that some screwcap shells disguise themselves, mimicking the shape and texture of stones, dung, or unappetizing umbrella polyps.
One genus of screwcap shells exhibits extreme sexual dimorphism. Dirgud females remain fixed in place for life and raise their young right inside their shells while the shelless males swim around and hunt for food to bring home. Without a male, the female could not glean enough nutrition for herself and her young from filter-feeding alone. When danger threatens, the male will also slip inside the shell.
Kaleidoscope Puzzle Sponges:
On Earth, organisms often advertise their toxicity with contrasting colors. In the reefs of Ectora, most things are already brightly colored and so toxic organisms advertise their toxicity by changing color. Thus one family of puzzle sponges continually switches hue in complex patterns. This warns away any grazers as well as any predators that might otherwise consider following a school of fitters inside. While many puzzle sponges will ooze caustic fluid when torn, the kaleidoscopic ones contain a very strong, very thick, non-dissolving fluid that will run up the claws of any attacker and find every crevice in the shell before melting the flesh away. Furthermore, while most puzzle sponges are somewhat toxic to eat, the ones in this family are so toxic that they shouldn’t even be touched. This family of plankton-eating puzzle sponges have narrow, slit-shaped gaps between their units just big enough for fitters to slip inside. They change colors by expanding and contracting pigmented cells under the skin by the same principle that their larval forms use to slide their units past each other.
Rainbow-Edge Tallweed And Kin:
The rainbow-edge tallweed is a type of poisonous weed with a chromatophore-laden edge that changes color in rapidly propagating stripes.
Weeds are multicellular, photosynthetic organisms common in the reefs whose cells contain green and purple chloroplasts. This gives them a dark, grey-blue color. Some weeds are small, soft-skinned, and ruffled in order to better exchange dissolved nutrients. On the other hand, most are large and have thick, tough skins to deter herbivores. To exchange nutrients, they have a vascular system that includes blood, heart(s), and gills distinct from the light-gathering leaves (if any). Cells throughout the body freely detach and ride through the bloodstream, soak up the nutrients they need in the gills, storing them in vacuoles, again ride through the bloodstream, and finally take the place of another cell with depleted vacuoles. Often, the blood pathways will change position the same way rivers erode one bank and build up another. Gas in the vacuoles in each cell is what makes most weeds so buoyant.
Tallweeds are one family of tall, single fronds attached by holdfast to the seafloor with small, spiral gills placed periodically down the middle on only one side and that reproduces by spores (both sexual and asexual) produced anywhere on the skin.
Written by Daniel Noe, ChampionOfTheGalaxy.com