Anima Ex Machina: Extra #4 [Ixodida Lifecycle]
One of the things that still hasn't been fully fleshed out is the lifecycle of the ixodida parasite. For this reason, a lot of this is only bare-bones; it's liable to change later on down the line if or when I decide something else would work better.
Furthermore, while I'm not a genius in biology, I'm secretly a bio geek. Hence, you'll be seeing a lot of very nerdy terms throughout this article. I apologize and promise to define everything, even if I fully acknowledge that I'm just doing it for the gratuitous bio geekery.
To start things off, as I've said in the extra about pronouns, the ixodida parasite is hermaphroditic. For those of you who haven't taken Bio 101, this means that the parasite has both male and female reproductive organs. As a result, it can reproduce one of two ways.
The first and most preferred way is via allogamy, in which one parasite lays a batch of eggs for another parasite to fertilize. To be a bit more specific here, parasites normally live in groups called "seas." These seas usually comprise more than one hundred individual members that all hunt together. When they come across prey (usually an animal several times larger than they are), they overwhelm it and drain it of its bodily fluids. Afterwards, each member of the sea lays hundreds of eggs (usually suspended in a green, gel-like egg casing) in the remaining tissue and moves to fertilize the eggs of the parasites closest to it before moving on to find new prey. The eggs will hatch and immediately excrete acids to corrode the tissue of the host carcass for consumption. Because the parasites are mindless at this point, it's very likely that hatchlings will accidentally eat each other or consume the carcass and starve late-hatching parasites, so the population is well-regulated by nature before a new sea is fully formed and ready to move onward.
If a parasite is somehow separated from its sea, the fact that it's a hermaphrodite also means that the second and less desirable option is autogamy, wherein the parasite goes through the same process (locating and killing prey, draining its fluids, and laying a batch of eggs) but fertilizes its own batch instead of someone else's. This is undesirable for two reasons. First, the ixodida parasite is small on its own, and its prey is typically many times larger than itself. It's not unheard of for a parasite to kill something by itself, but it's still more likely that the parasite will simply be killed by its wild prey. Second and most important, the parasite is forced to scramble its own genetic code in order to produce varied offspring. This is akin to in-breeding and typically results in genetic defects, usually mental in nature. (During the genetic scrambling process, the ixodida's main priority is to produce offspring that may potentially have a different type and rank as itself thanks to the species' reliance on the idea that the adults will be structured in a sixteen-part social system based on both. As a result, less emphasis is placed on weeding out the other glitches that might result from an extremely small gene pool.) Case in point: Abel. Electric-type drone but dumb as a brick.
This brings up the next point: the ixodida's parasitism. As mentioned above, the ixodida life cycle starts off with hermaphroditic parasites living in a massive sea. Technically, they can live all their lives (a lifespan completely dependent on the planet's environment) in such an arrangement, and most of them actually do. Parasitism requires a lot of effort, and because the sea provides all the food and reproduction partners the creatures technically need, the ixodida don't actively look for hosts.
However, the adult form is extremely important to the ixodida nonetheless. Individual adult-forme ixodida are better adapted for hunting and form a social system that supports a single ixodida known as the imperial ixodida (emperor if male, empress if female, imperial to refer to both genders). This ixodida has the ability to maintain what's known as the "colony" (the planet-wide community of ixodida) through means and for reasons that I'd prefer not to bring up because it's full of plot. The short of it is that without the imperial in place, even the seas are bound to die within a couple of months.
Third and most importantly, the host serves as a vector and vehicle: while the seas can travel quickly, adults can travel easily. Usually, they have the means to overcome obstacles that seas can't, and the fact that the parasites typically infect the dominant species of a planet means that they gain access to the species' technology and population. This means that the ixodida can spread to places normally unreachable for seas such as continents or islands. (Fun fact: On their home planet, the entirety of the ixodida species had been confined to a tropical island until a member of the dominant species stumble across them. It's through this hapless explorer that they were able to spread to the rest of the planet by hitching a ride on it and forcing it to bring them across oceans. Yes, despite being able to survive the vacuum of space, ixodida seas are, for whatever reason, deterred heavily by a strong current of water. Go figure.)
With that in mind, if an ixodida parasite comes in contact with a living being, it first bites into their prey, no matter what species it is. It's a bit hazy to the researchers in the great cosmos how the parasite determines whether or not what it has is a potential host, but theories suggest it could have something to do with the antibodies in the blood or certain codes of DNA. Whatever it is, the parasite "reads" its victim. If it's food, it's quickly disemboweled. If it's a potential host, the parasite burrows into the skin until only the top hemisphere of its body is exposed. Through the use of the hive-minded network, the other parasites know to retreat once a successful implantation occurs. This is because not only would multiple parasites infecting the same host result in lethal problems during the transformation stage (read: problems that would cause both the host and the parasites to become massive blobs of cancerous cells) but also, in addition to being carnivorous, ixodida have the potential to be cannibalistic: the adults are just as likely to consume the parasite as they are any other type of prey.
Once implanted, the ixodida grows tendrils under the host's skin at a rapid pace. These tendrils excrete a combination of mutagens similar to those that trigger evolution in normal pokémon. However, because the host is usually not capable of evolution (as this is one of the factors that the parasite looks for while "reading" its victim), its body doesn't know how to adapt to the hormones. As a result, the process is much slower and a lot more gruesome than evolution. (It typically takes up to two weeks, and the host's body doesn't absorb lost tissue in the process.) The other secretions by the tendrils are proteins that accompany the mutagens. These help force the host's DNA to rewrite itself according to parts of the parasite's own genetic code. Hence, the end result is an alien creature bearing both the features of the host's and parasite's species -- a hybrid, if you will.
After that point, the ixodida's very basic instinct is to spread to new places, although the species' actual goal can be overwritten by the imperial. After transformation, typically, drone ixodida are sterile, although they still have genitalia dependent on the host's original gender. Monarchs are fertile, but they can only reproduce with other monarch ixodida. Ixodida gametes (sex cells -- either sperm or eggs) aren't compatible with those of normal pokémon (in the same way a human can't just fertilize a chicken egg), and the structural changes in the host's genitalia prevent successful reproduction with a member of its own original species. (It's theorized that it's possible but just about as rare as getting struck by lightning more than twice in the same storm.)
To put it in short, females lay eggs that are somewhat smaller than pokémon eggs. These have soft shells that enable the fertilized egg to expand to the same size as a newborn baby of the host's species. After which, the shell hardens to a rock-like consistency after a few days. (During the time between fertilization and the point where the eggs harden, the parents are extremely territorial and likely to attack without provocation. They maintain a territorial attitude after the eggs harden, but it's to a slightly lesser degree. Imperial ixodida, however, will always be extremely violent when it comes to protecting their unborn hatchlings.)
Males, meanwhile, possess a tube in place of normal genitalia. The tube is usually retracted into the body, but it extends during mating to stimulate the female into laying an egg and to fertilize it right after it's in the open.
As implied by the above, females normally lay only one egg every few months. Additionally, males and females pair up into monogamous relationships: adult ixodida (of the same type) will only spawn with one mate until either of them die. Researchers believe this is because monarch ixodida, being strategic thinkers at heart, can adapt to each other in order to establish a partnership best suited for protecting their eggs. In other words, ixodida mate for life because the couple eventually learn how to best use each other's skills to fight off threats to their young.
Meanwhile, inside the eggshell, the zygote will split early in development. Half of the remaining will follow remnants of the host's DNA in order to become a baby of the host's species; the other half will become an ixodida parasite that will infect the fetus close to birth. As a result, offspring born to ixodida parents will always be monarch ixodida as soon as they're born.
Because of the speed at which this happens (i.e., because the egg takes nearly a year to hatch, as opposed to the day-long incubation period of parasite eggs), it's not a preferred method of reproduction for the ixodida. Rather, it's the adult's duty to find a mate and to transport parasites to potential places of breeding. Once at a suitable location, the parasite detaches from the hosts, killing them in the process. (This is also used as a defense mechanism if the environment has suddenly become unsustainable for the host. The parasite lacks many needs and can go into a period of hibernation that can last for thousands of years. Think tardigrade-level of indestructibility.) After that, the two parasites mate with each other and begin a new sea in their new environment. Thus, the lifecycle of the ixodida is complete, and the parasites are free to die. (Parasites that detach from their hosts rip up vital parts of their body in the process. The exertion usually means that if they spawn, they'll die shortly afterward. Parasites that don't spawn right after detaching from a host can recover and find a new host.)
Through this manner, ixodida are capable of locating new food sources and safer breeding grounds fairly easily, but the monarchs' ability to reproduce serves as a failsafe. That is, if the adults can't reach a suitable location before the end of the host's lifespan, the parasite will force it to mate with another monarch in order to produce a new vector to carry the ixodida species.
As a related note, this explains why drones travel in packs of like types: because the drones serve as protectors for the ixodida meant to spread their species around a planet. Additionally, it's worth mentioning that not all ixodida follow the instinct to travel, detach, and breed. Adam is a prime example of this.