Common Name: Sydian (singular); sydians (plural)
Binomial Name: Homo sydianensis
Sexes: Male and female
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Sydians are covered in chitinous plating, with only the face and, in females, the front torso and groin exposed. Located under the porous chitin are glands that secrete a corrosive enzyme. While concentrated in the antennae and tail fuzz, they are found all over the body. This enzyme catalyzes oxidation of (i.e. rusts) most metallic elements. When living tissue is exposed, the enzyme stimulates low-level ion exchange in the nerves, causing a feeling of pleasure. On non-metallic substances or organisms lacking nervous systems, the enzyme sits inert or is absorbed without effect. The enzyme-generating cells bear surface structures with their own DNA; similarities to mitochondria suggest incorporation of protobacteria or archaea into sydian cellular biology. All sydian cells also contain mitochondria with mtDNA nearly identical to that of Homo sapiens, indicating common ancestry. Sydian secretions have a slight citrus flavor and aroma, possibly due to acidic enzymes adapted from the protobactera or archaea.
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Sydian dietary requirements include heavy metals alongside water and organic nutrients; colonies form when the three are found in close proximity. Freshwater bodies carrying fish and trace metals are common sites. Isolated colonies have developed rudimentary farms using scavenged or stone tools once forage no longer supports population growth. Lone individuals, social groups without settlements, and those in frequent conflict exist as nomadic hunter-gatherers, sometimes for generations before a colony is founded.
Recent research has shed light on the role of metals in sydian biology: individuals deprived of metals can survive on food and water for months but suffer from blood poisoning as the enzyme-generating cells in their bodies die. The replication of the organelles on the cell surfaces during mitosis requires heavy metal compounds. When these compounds are not available, a hormone messenger from the organelle interrupts mitosis and the cell lyses to release usable metals for other cells, along with metallic waste stored within the organelle. As the number of generative cells dwindles, the remainder can no longer reuptake enough of the metallic waste from the blood plasma, resulting in heavy metal toxicity. Sydians deprived of organic nutrients or water suffer ordinary malnutrition and dehydration, respectively.
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Female sydians do not have an established breeding season and ovulate multiple times throughout the year. Roughly every 240 days and lasting up to 30 days, regardless of estrous phase, female sydians begin to crave the oxidizing enzyme of other sydians; male-female interactions during this state almost always result in intercourse. This heat-like state is indicated by the head hair becoming fiery orange and the affected female seeking out other sydians more diligently. The change appears related to the release of extra luteinizing hormone during a heavy ovulation; the hormone acts as a cupric receptor antagonist to the bacterial organelles, preventing uptake of inorganic copper. The metal settles in body tissues, including hair follicles, provoking a strong craving for additional sources of enzyme to chelate it. The receptive state can be triggered artificially by fertility treatments with LH components, and an active pregnancy suppresses or diminishes the condition. While males prefer females in the receptive state, they are not above seducing non-receptive females or employing physical force to breed.
During either consensual couplings or forced copulation, the male penetrates the female with his penis, ejaculates, and potentially impregnates the female, who ovulates two to three eggs in each cycle. Embryos attach via hemochorial placenta to the uterine wall. Gestation lasts six months, after which the female gives live birth. Sydian embryos are colonized by the mother’s enzyme-producing organelles late in the first trimester, and it is surmised that these organelles trigger accelerated growth and the development of chitin in place of keratinous vellus hair. Pure human and mixed-breed embryos develop indistinguishably from sydians in sydian wombs, excepting variations in head hair that do not appear in pure sydians. Sydian embryos grown in human wombs or in vitro resemble human fetuses. Sydian children are born with scaly, soft gray chitin that persists until puberty. Puberty occurs between the ages of eleven and thirteen, whereupon the chitin scales thicken into the sex-appropriate adult configuration, darken, and join together.
