
Name: Schalenhai (Calciplacatichthys duoventis) [chalk-plate fish of the second wind]
Creator: OviraptorFan
Ancestor: Twilight Neodevorator (Neodevoratorus primucrepusculum)
Habitat: LadyM Tropical Ocean, North LadyM Subtropical Ocean, South LadyM Subtropical Ocean
Size: 2.64 meters long (adult), 27 cm long (Juvenile) 5mm long (newborn larvae)
Support: ?
Diet: Adult: Carnivore (Siluros, Swarming Roufos, Carpolinka, Chambered Siluro, Common Naelk, Common Roufo, Dappershell, Nautcracker, Oceanic Lantern, Ripplegut, Stallephas, Starcrusher, Striped Nautstar, Rhombill, young Schalenhai), Scavenger, Kleptoparasite Juveniles: Scavenger, Carnivore (<5cm), Filter-Feeder (<2mm) Larvae: Filter-Feeder(<300µm)
Respiration: ?
Thermoregulation: ?
Reproduction: Sexual (Male and Female, 5cm tall Egg Sacks), Asexual (5cm tall Egg Sacks)
In the wake of the end-binucleozoic atmospheric disturbance, the devorators were one group that suffered greatly, with nearly all members of this once proud lineage dying out. But down in the depths, one species made it through to the other side, being the Twilight Neodevorator. In the aftermath, the oceans had pretty much cleared of megafauna, meaning anything had a chance to take over if they responded quickly enough. With their effective respiratory system, the Twilight Neodevorator had a particular advantage over other taxa during this time of lower oxygen levels, so they would begin to grow bigger and enter surface waters. Despite this, however, the low amounts of nitrogen meant the exoskeletons of pure chitin no longer worked for large organisms, which in turn meant the growing Twilight Neodevorators had to develop ways of dealing with this problem, which among other things led to these groups splitting off into a unique taxon of their own right.
Known as the Schalenhai, these new predators have grown to over four times the size of their ancestor, rapidly taking the role of top predators. This large size is possible due to both their respiration and their support. When it comes to respiration, the Schalenhai use their ancestral adaptation, using powerful muscles around the gills that actively pump in and out water. This means more water goes through their gills, which then means more oxygen enters their bloodstream, which is critical for sustaining their large size during a time where oxygen levels are fairly low. This adaptation can also be still used for their original function, allowing the Schalenhai to enter a state of dormancy for periods of time, usually entering a state like this after bouts of intense activity like hunting down prey to then conserve energy and use less oxygen. Another major adaptation, one that is a recent development, relates to the Schalenhai’s exoskeleton being now primarily made up of calcite rather than chitin. Since calcium carbonate is quite abundant in the seas, this adaptation allows the Schalenhai to get around the problem of nitrogen levels being particularly low at this time.
With both of their adaptations relating to respiration and support, the Schalenhai is able to reach their enormous sizes, which in turn makes them the undisputed apex predator in the region. Being by far the largest predator in their ecosystem, almost anything else of decent size is on the menu for the Schalenhai. To hunt the various prey in these seas, the Schalenhai relies upon its ancestral adaptations and some new ones which had evolved in response to living in sunlit waters. For example, the Schalenhai’s exoskeleton has lost its iridescence, such having it shine brightly might give it position away to prey before it can get close enough to attack. Additionally, the Schalenhai has much more prominent countershading, helping it hide in a place where there is no cover to speak of. While it will try to get as close as it can towards a target to reduce the overall distance, the Schalenhai can also keep up a sustained pursuit. The effective respiration means the Schalenhai won't tire quickly during these bouts of high activity, while their streamlined shape and the denticles covering the exoskeleton means they won’t be slowed down by drag. The extra heart chamber inherited from its ancestor still helps circulate blood more effectively, getting vital oxygen around their body quickly and thus improving muscle performance which in turn means greater acceleration and mobility.
Once it gets close enough, the Schalenhai will try to grab the target with their feeding tendrils, relying less on ramming prey like their ancestor did. As the prey is caught, the tendrils will be retracted halfway into their cephalic sheaths and crush the prey. Two small prongs at the tip of a tendril that are made of calcite help with puncturing the target and help hold in place to prevent its escape. When killing prey, the four chitinous plates around the eye will come together, protecting the eye from potential damage if the prey struggles. The four facial plates still mean the mouth ring can expand to a fairly large size to consume its catch. As the prey is digested, the energy extracted from it will either be used immediately for body functions or will be stored as fat underneath the outer exoskeleton layer as a reserve for lean times.
Some parts of the Schalenhai’s body have not really changed. For example, the species still possesses a true brain, helping it to process information more quickly and effectively than the cerebral ganglion seen in more basal devorators. There is also still a small layer of fat underneath the exoskeleton’s surface layer, strengthening the armor against blows by absorbing the energy of crushing and squeezing attacks. This adaptation also protects the exoskeleton against high-strain impacts, though this is primarily used for intraspecific conflict since the species does not ram into prey as much.
As the Schalenhai is highly nomadic, it's inevitable that individuals will come across each other. Outside of the breeding season, these are typically random encounters which result in both individuals periodically flashing the UV patch on the top of their head as a warning. The winner of these “fights” is determined by who has the more complex sequence of flashes and how long these sequences last, with the loser quickly swimming away in the opposite direction. If two individuals are evenly matched, they will then escalate to a physical fight, swimming towards one another at high speeds to ram eachother. In these jousts, it's who breaks away from their charge first or is knocked out cold that a winner is determined. Schalenhais rely on these displays and jousts to avoid a truly violent fight, as such a battle could easily prove fatal for both combatants.
During the early spring months, females will become reproductively active, releasing pheromones into the water. As the species still uses scent to locate prey, males easily pick up these pheromones, where after they will begin to follow the trail to the source. Once a male has tracked down a potential mate, he will begin to use all of his UV patches, as only the males retain UV patches on parts of the body besides the top of their head (having UV patches on their dorsal fin and along their flanks). In these displays, it's all about the sequences and duration, with females only picking the ones that have the longest and most complex of displays. The mating process is identical to that of their ancestor, with the two locking their back fins together while mating belly to belly. Since the species has much more elaborate mating rituals than their ancestor, female Schalenhai will retain their egg sacs within their bodies. There are only two cases where a female will release the egg sacs, either when it has been fertilized by a male that had mated with the female, or close to the end of the breeding season. As the breeding season lasts about six weeks, a female will likely be fertilized by a male, but if she hasn't late into the season then she will fall back into parthenogenesis. The young inside the egg sac will begin to develop and the whole egg sac will be expelled by the mother. Since there is no incentive to males to try fertilizing the floating egg sacs, the egg sacs no longer glow with UV light. The young that hatch from these fertilized egg sacs will be still all female.
The resulting youngsters, fertilized or unfertilized, start their lives as small soft-bodied filter feeders. Being vulnerable to a variety of predators, including adult Schalenhais, these youngsters stick together into schools that can be hundreds strong. As they grow in size, they will begin to break up into smaller and smaller groups, with these youngsters starting to grow in their exoskeleton at around 27 centimeters long. These start as 3 slim “prime rings”, which start off as pure chitin. As they grow in size, the rest of the exoskeleton will grow in while also using more and more calcite.

A young Schalenhai.
Alright guys! Here is my first ever species of beta! How does this look? Feedback is highly appreciated!
This post has been edited by OviraptorFan: Feb 15 2023, 01:40 PM