Ganulia
The ganulia (pronounced /gəˈnuːljə/) is an enormous ray that lives in the oceans of Dadauar. Ganulias feed by taking in seawater through their mouths and expelling it through their gills, filtering out and digesting any organic matter that gets caught in the process. Its feeding process is also its primary means of locomotion—the expelled water acts as a jet to propel the creature forward, although it may choose to expel the water less forcefully if it wishes to eat while floating in place. If necessary, the ganulia can swim using its fins, but it rarely has reason to. It therefore tends to move in fits and starts, jetting forward a few tens of meters and then pausing while it takes in more water, spurting forward again as it expels its new gulletful. The ganulia tends to stay at or very near the surface of the water, very seldom having any need to submerge.
The intelligence of ganulias is the subject of considerable debate. While most ichthyologists believe them to be within the upper level of the typical range for a fish, there are those who believe them to be much smarter than that, and perhaps even ellogous. So far, there has been no conclusive evidence one way or the other. Ganulias seldom respond to any attempt at communication, but it's impossible to tell whether that's because they don't understand, or merely because they're not interested. It's also been proposed that the complex infrasound "songs" ganulias produce as they travel are a true language that the ganulias use to talk to each other over long distances, but if so no one has yet been able to decipher it. There have even been some stories of ganulias with the ability to cast spells, though none of these have been substantiated.
Because the ganulia almost never goes underwater, and because its motion is relatively slow, it is often seen something as a living floating island. Indeed, in many ways it does function as such; semiaquatic or even terrestrial organisms often colonize the ganulia's dorsal surface, and entire small ecosystems can form there.
Description
The ganulia has a typically batoid form, with a fusiform body that spreads out on the sides into wide triangular pectoral fins. The ganulia's body proper, excluding the fins, is called its "disc", though its shape is more oblong than circular. Seen from above or below, the ganulia is nearly rhombic in shape, slightly wider than it is long. At the front of the ganulia's head is a wide, gaping mouth, flanked on each side by a flattened projection called a cephalic fin. Its eyes are located on the sides of its head, and its backward-facing gills are on its ventral surface. The ganulia has almost entirely lost the long tail possessed by its ancestors and relatives, its only vestige being a short stub.
A typical adult ganulia measures about forty meters from head to tail (not counting the cephalic fins), and fifty meters from (pectoral) fintip to fintip, and has a mass of about two hundred metric tons. Flattened dorsoventrally, it measures only some eight meters from top to bottom. Some individuals, through advanced age or just genetic variation, can be much larger; the largest reliably reported ganulia had almost four times those linear dimensions. Most ganulias are dark brownish grey on their dorsal surface and somewhat lighter on the ventral, though it's common for ganulias to be so covered in detritus and epibionts that little of their skin is visible.
Anatomy
Like other chondrichthyians, ganulias have skeletons made of cartilage instead of bone. The brain is protected and the head given its shape by a large cartilaginous enclosure called the chondrocranium. A cartilaginous vertebral comumn extends from the back of the chondrocranium to the vestigial tail, and keratinized filaments called ceratotrichia run through the ganulia's pectoral fins. Aside from the spine, there's relatively little skeletal structure in the ganulia's disc, mostly a pectoral girdle and pelvic girdle supporting the anterior and posterior parts, respectively, and the gill bars that separate the gills. Because of the röle the gills play in the ganulia's propulsion, its gill bars are firmer and proportionately thicker than those of other rays, and unlike most of its skeleton are partially calcified. This means the gill bars are more likely to be preserved than other parts of the skeleton, and on rare occasion gill bars from dead ganulias are found washed up on beaches; before their provenance was understood, they were called whalebeams, and this term is still often used today despite its now being recognized as a misnomer.
The mouth of the ganulia differs from that of its smaller relative the manta ray in that it entirely lacks teeth, but has a much more mobile jaw. This is related to the difference in their feeding patterns; while both are filter feeders, mantas simply let the water pass through them as they swim forward, while ganulias actively suck water into their mouths and expel it through their gills, requiring that they open their mouths wide for the suction and close them for the expulsion. Rust-colored structures called gill rakers fill the space between the gill bars and filter the water, passing particulate matter down the ganulia's esophagus toward its stomach for digestion. From there, the matter passes through a short intestine, which consists of two parts: a short duodenum and a longer, tightly coiled part called a spiral valve. At the end of the spiral valve is the rectum, from which waste is expelled through the anus into the cloaca and thence to the water outside.
Distribution
Ganulias have a cosmopolitan distribution, being found in all five oceans of Dadauar, though they are rarely seen in the interior seas aside from the Golden Sea and the Akararal. They seem to strongly prefer temperate and tropical waters; while they have been occasionally spotted in the pageric part of the Duhhian Ocean, they never seem to linger there but only to pass through it on their way between the ocean's warmer parts to the east and west. Ganulias seem to be most common in the southern Camilout, to the west of the Talacho Peninsula, and it's here that they're believed to have originated.
Diet and ecology
Ganulias eat just about anything organic that comes into their mouths—which generally means mostly plankton, but ganulias do eat fish and other epipelagic marine life as well. Ganulias move slowly, and most intelligent creatures know enough to get well out of the way when they see one coming, but the suction the ganulias produce when they're taking in water is certainly enough to take in larger animals—including humans—unwary enough to be swimming in their path. The cephalic fins play a role in guiding food toward the mouth as well.
Though it might seem a large source of meat, the ganulia has few natural enemies. Its flesh is toxic to most predatory organisms, including humans—it's not a deadly poison, but it's enough to sicken those who consume it. Those few organisms that might decide to feed on it anyway are warded off by the colonies of defenders that grow on the creature's underside.
Reproduction and life cycle
As with other rays, ganulia copulation requires the male to insert one of its claspers into the cloaca of the female. In the ganulia, the claspers are asymmetrical, one being stunted and nonfunctional while the other (usually the left, though on some individuals it is reversed) is much elongated, capable of reaching lengths of several meters though kept coiled in a myxopterygial pouch when not in use. This, along with the anterior positioning of the cloaca, which is located just under the tail, allows ganulias to mate without either needing to submerge, rather than having to press their ventral surfaces against each other as is the case for most rays. Even so, getting into position does require more careful maneveuring on the part of the ganulias than they otherwise generally find necessary; through subtle motions of their fins they carefully align themselves tail-to-tail close enough for the male's clasper to reach. Once the clapser is inserted, it takes several minutes for the male to pump sperm through the clasper into the female's oviduct, with the aid of organs called siphon sacs. Once this process is complete, the two ganulias may immediately separate and go their separate ways, but mating ganulias have sometimes been witnessed remaining "attached" to each other for extended periods of time, perhaps as long as several days. This seems, however, not to be a required part of the procreative process.
Ganulias are ovoviviparous; the embryos grow in egg cases, but they remain inside the female until after they hatch, so the young are born live. They have a long gestation period, just over a year. Usually, only one eggcase is produced at a time; multiple births do happen among ganulias, but are uncommon.
Ganulias can live at least two centuries, and there is some indication that they may live for much longer. There are stories of an enormous ganulia called Kukunga that bears on its back the ruins of a city thousands of years old, but most people dismiss this as a myth.
Epibionts
A large number of other organisms live on the ganulia's back as well as on its underside. Some of these are phoronts that only temporarily "hitch a ride" on the gigantic ray, but there are others that live there more or less long-term, including some organisms that specialize to dwell on ganulias as their sole or primary habitat. Among the latter are hidecrawlers, flattened relatives of mudskippers; sea mums, a family of phoronids; and key lice, larger kin of the whale lice that inhabit cetaceans (which, like the latter, are not true lice but crustaceans related to skeleton shrimps). Epibionts that are commonly but not exclusively found on ganulias include sea lichen and various types of barnacle, crab, snail, sponge, algae, and coral. Some creatures, such as the lamprey squid and the shockworm, feed on the ganulia's blood but in turn defend it from predators who might do significantly more harm to it if unchecked, their relationship with the ganulia therefore perhaps being mutualistic.
Over time, the creatures that die and decay on the back of a ganulia produce a kind of humus that is able to support other forms of life. From seeds and spores either carried by the wind or brought by flying animals, plants may become established there, first grasses and small herbs and then larger plants as the organic matter further accumulates; a sufficiently old ganulia may even bear trees on its back. With the plant life often comes the arrival of otherwise terrestrial fauna such as lizards, beetles, and rats perhaps reaching the ganulia either by rafting or by swimming or (in the case of birds, bats, and insects) flight when the ganulia passed close to shore.
It is not only beasts and flora that have made their homes on the backs of ganulias. Entire settlements have been built on the backs of some ganulias, small independent societies beholden to no landbound ruler. Most of these communities are primitive, but there are a few petty onirarchies located on the backs of ganulias, ruled by onirarchs whose powers pale in comparison to those ruling larger lands with many more dreamers to draw from, but are more than sufficient to reign over their tiny demesnes. Other ganulias have stockades on their backs that serve as the headquarters to rebel groups.