drew some inspiration from subnautica--otherwise based on the frilled shark, diplocaulus, and mosasaurids
info below vv
Species Overview
As pictured above, guardians are extremely large, predatory creatures, although they are generally docile unless provoked. Guardians possess effective counter-shading, a flexible body, partially translucent fins, and a large frill on their skull. Due to roaming the deep sea for a large portion of their youth, they have very poor eyesight.
Lifecycle & Hunting Behaviours
Almost immediately after hatching, a guardian will begin hunting in the murky depths of their nesting grounds, which can be found in volcanic ocean trenches. Because the surrounding area is so dark, this species has evolved to use echolocation. Until they get big enough to school together and ascend to the shallows, they feed on microorganisms, shellfish, and crustaceans.
Juvenile guardians make a dangerous journey to shallow waters once lifeforms in the trenches can no longer sustain them. Together, they form a pod of no less than 7 individuals. The importance of this specific amount of juveniles travelling together is not yet understood. Once they reach sexual maturity, the guardians split from their pod and begin establishing their own territory.
Adult guardians primarily consume large, mollusk adjacent invertebrates which burrow into sand or corals for shelter. Using their shovel-like frill while pressing their bellies against the sea floor, they disturb the sediment and utilize echolocation to see underground. After the guardian locates its prey, it emits a low frequency vibration in its throat that is powerful enough to shake the burrow and drive the invertebrate out of hiding.
Guardians are also opportunistic, scavenging from large kills that have been abandoned. They may challenge one another over a body, but rarely stand up to other similarly sized carnivore species.
Mating rituals and end of life practices are yet to be observed.
Echolocation
At first glance, the rings atop a guardian's head may look like eyes. These rings are actually organs that the guardian is capable of rapidly dilating and constricting at will, producing an ultrasonic frequency that allows the guardian to "see" its surroundings more clearly. A guardian's eyes and beak are actually located underneath its frill and are not pictured in the reference image.
Given that their rings resemble eyes, it's also a useful defense mechanism that discourages predators attempting to ambush the gaurdian from above.
(Sorry about the low quality of the image!)
INFO BELOW
The Silicanus are a species of amphibian adjacent aliens. They have a flexible backbone and skull, but their limbs are rather uniquely, boneless. They have a very nervous look on their faces, which have surprisingly humanoid proportions. Their eyes are large and wet, and their mouths are small and give them a look of innocence. They have a varying number of antennae on their heads, designed as sensory organs. Their noses are rudimentary, developing scent glands as they move further from their natural water habitat.
They come in a variety of colours. Their tentacles, which are attached to their heads and back, are often styled like human hair, so they have an edge of familiarity in their appearances. Their respiratory organs are attached to their lower back, and look like little tails. These organs can work in any environment, but must be wet in order to function properly. (If it wasn’t for the pressure of space, they could survive there, too! They’re very resilient)
The silicanus have a variety of sexes, but the most common variety is adjacent to what we would call ‘female’. The ‘males’ often do not survive in their eggs, due to an unknown health issue linked to their sex chromosomes. In reality, there are far more than just ‘male’ and ‘female’, and it’s not really accurate to call them that.
The reproduction process for the species is strange. There are two ways of reproducing, though both will end in the same result. One, a Silicanus will lay unfertilised eggs, which at least 2 other Silicanus must fertilize in order to make them viable. Then, after the eggs hatch, the larva will be fed nutrients by a variety of Silicanus separate from the first three parents.
The other method is similar, but less common. The eggs will be fertilized inside the Silicanus, then laid. This method is uncommon due to a lack of sexes able to directly fertilize (ie, ‘male’ for our understanding.)
Due to the reproduction method and their naturally social nature, Silicanus will live in communities called clusters. Typically, clusters have around 20 members, but clusters as big as 60 have been documented. Clusters will raise offspring communally. When reaching adulthood, the offspring may stay in the cluster, or might leave to find another cluster.
The issue of inbreeding seems quite nerve wracking given that some offspring stay in their cluster, but in modern day, they might bring mates from another cluster, or might simply choose not to breed.
Clusters can resemble human polyamorous relationships, which, can be the case, but more often than not, they function like a family unit, with smaller relationships within. If not in a cluster, Silicanus might form a smaller group, which is definitely more reminiscent of a polyamorous relationship. These groups are often found in big cities, since clusters are a bit harder to form in such densely populated areas.
As implied by their name, Silicanus produce silica as a byproduct. It can be found in their waste, but generally they just seem to excrete small amounts of it with their bodily fluids. The silica they make is something they have utilised for tool creation and forming both symbiotic relationships with other species, and taming them with tools created from the silica.
