Fish Folk

Figured I'd do some more world building.

Tridentites, colloquially known as Fish People, are a species of True Chimera*. They are sentient amphibious bipeds widely spread throughout the oceans and lakes of the world, and their exact origins are unknown. They were likely created or introduced to Earth's oceans during the Darkened Years.

Tridentite anatomy is highly similar to humans, as they were clearly based off of humans when they were created. For the most part height, weight, proportions, and other superficial details synch closely with human parameters -  the only exception being that Tridentites have longer legs on average. Skin tends to be pale grey-blue or green and of a smooth, hairless composition, condensing into pebbly, scale-like patches in several places: along the spine and shoulderblades, shoulders, forearms, hips, lower legs and feet, and occasionally on the cheeks. The colors of these scales were once thought to divide the Fish Folk into distinct races, but it has since become apparent that the scales change color to provide camoflage depending on the water temperature and qualities, as triggered by the protean gland (see below). For instance, the scales of a Tridentite in an inland lake will turn algae-green.

The Tridentite's hair and eye color and texture fall within human averages (and are the only way outsiders can generally distinguish the various Tridentite ethnic groups). Their eyes are large, with large irises, and their lenses can change both shape and position, making them unique anatomical mashups of aquatic and terrestrial vertebrates. This gives them excellent underwater vision. The protean gland can change the average level of contraction of the iris and several other factors to adapt to many different light levels and the cloudiness of water, as explained below. Tridentite noses tend to be small and flat, incisors are more pointed than in a human, and the outer ear is larger and of a more finlike structure. Similar fins and cartilaginous spines line the outer edge of their forearms, calves, elbows, and just below the ribcage, where their gill covers are. They have long, webbed toes, but not hands.

Internally, Tridenties have three major differences from humans. Fatty tissue in one of the fish people is filled with small gas-filled sacs whose exact purpose isn't clear, though because they expand and contract in the presence of the hormones emitted by the protean gland it is theorized they serve as dive bladders to help the Tridentite maintain buoyancy at different depths. The respiratory structure of the fish people is truly unique - they have no diaphragm, as the walls of the lungs are muscular and work to pump water from the mouth, through the lungs, and out the gill openings just below the ribs. The lungs (called such only because no one has come up with a proper name to describe this organ) are filled with oval structures that can serve as either alveoli or gill filaments. If the Tridentite finds herself above water, the protean gland causes her gill openings (operculum) to seal shut, the internal structure of her lungs to warp to better accommodate air, her lungs to expand and contract differently, and in a few seconds she is breathing in and out similar to how humans do so. The level of versatility Tridentites enjoy due to this as amphibians is incredible - there are very few places on the planet where they cannot breathe with relative ease.

(Before you inevitably ask, yes, they have breasts above the gills - Tridentites are mammals, even though many of their tissues and metabolic processes are closer to ocean fish, and they reproduce just like humans.)

The protean gland, as you may have guessed, is the most miraculous part of a Tridentite. Literally, in fact, as it has a subtle, naturally-occurring magical enchantment to bolster its effects. The protean gland releases a wide range of hormones in response to external stimuli that rapidly alter the Tridentite's body. Bones get harder or softer, skin changes how liquids and gasses permeate through it, pigment glands under the skin activate, heart rate changes, blood composition changes, all with the net effect of swiftly adapting the Tridentite's system to a huge range of environments, from freshwater lakes to rivers and oceans from the arctics to the tropics. They can even survive on land in environments dry enough to easily kill their smaller amphibian brethren (though like humans living at high altitudes, this isn't very comfortable and opens them up to a number of medical risks they wouldn't have to worry about otherwise.)

As mentioned, Tridentite population is widespread throughout the world's oceans, though the total population is probably less than a billion. They are a mostly stone-age people technologically (it is rather hard to discover fire, blacksmithing, irrigation and the like when you live underwater). The majority of them are hunter-gatherers, with a few semi-nomadic herders. There are about five Tridentite settlements worldwide that would qualify as cities, and the governments of these city-states are the most complex level of organization the Fish People have exhibited. Researchers have identified at least twelve distinct language groups, and at least one of the city-states has created a pictographic writing system. Tridentites dress in clothing made from sharkskin or fish hides backed by cloth woven from kelp. Nudity taboos vary between individual groups of Fish People, but they always leave their stomachs uncovered to give their gills room. One group that lived in deep ocean trenches was observed to collect bioluminescent fish and train them as living light sources, or to crush them and mix them with minerals collected from the ocean bed to create a brightly glowing body paint. Tridentites who live near settled shores frequently trade deep ocean fish and cloth with humans in exchange for metal goods and wood. Curiously, though some isolated settlements have had such contact with the fish people for decades, the world at large did not become aware of their existence until relatively recently. Some see a conspiracy in this, but it is more likely the fish people simply avoided the water pollution around main human settlements and shipping lanes and thus never had widespread contact. It should be pointed out that the majority of Tridentites still live deep enough in the ocean and far enough from shore that they have only a vague understanding of the concept of land, and may not know of humans at all.

Incidentally, the name "Tridentite" was coined during one of mankind's first major encounters with the fish people, when a repair crew sent to check on a malfunctioning underwater communications cable off the coast of India found that some Tridentites had stripped bits of metal from the cable's infrastructure and fashioned it in to tridents for hunting small fish.

*True Chimera, as opposed to Piecemeal Chimera, have their own genetic code and are capable of reproduction. Hmm, I should start a blog post collecting all the details of my original setting like that. Could be fun.