Fan-Tail Mantis (Patreon)

Apparently, I never released the writing for this one either? Huh, that's weird, must've slipped my mind again...

The last paragraph is of dubious canonicity, I intended to make a post about Diyu organisms in captivity, but obviously I never got around to it.

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Fan-Tail Mantis (Squalloides pavomimus)

A perfectly acceptable phobia to have within Diyu is a fear of rocks, for there is a true possibility that every stalagmite, boulder, stone, or pebble may not be what it seems. The predatory tectopetracarians have specialized in camouflage as varying shapes and size of rocks and this has created eternal paranoia for residents of Diyu, as you can never be too sure if an inanimate entity is truly inanimate. Very often, the fate of many Diyuian animals is to casually walk by a seemingly innocuous rock, only moments later be ripped apart in the appendages of a hunting stone shrimp. This lifestyle is a far cry from their origins among tiny passive-feeding marine creatures hundreds of millions of years ago, but the tectopetracarians have long since traded their aquatic existence for a life on land. However, vestiges of this ancestry are still present in some form, particularly in more primitive species such as the fan-tail mantis. The paddle-like tail of the megacherians is still present, but now useless for swimming, it has been repurposed as a display organ. Normally hidden from sight and folded up, the fan-tail mantis's namesake tail can be dramatically spread out to reveal a vibrant blue glow. This is mainly used for intraspecific confrontations between other fan-tails and is present in both sexes, but works just as well to frighten off potential predators momentarily.

Fan-tail mantises are unusual among the stone shrimp for their far more generalist feeding habits, and up to half of their diet may consist of algae and fungal scum that accumulates in abundant concentration on moist rocks and stalagmites. Two pairs of flattened scoop-like forearms scrape off this scum and shovel it into the mantis's mouth. The fan-tail mantis populations concentrate around regions where this growth is most common, primarily along the coasts and within the undergrowth of exploding tree forests, where the moisture creates optimal growing conditions. Because their diet is not specialized upon algae or fungi, fan-tail mantises are not territorial over food supplies, and numerous fan-tails may occupy the same area within sight of one another. However, fan-tails are intolerant of other species feeding upon their scum, and will attack any other small animals on sight. However, short of simply being a territorial attack to drive them away, the fan-tails will rip apart and eat any scum-eating thieves they catch, because the other majority of their diet is animal prey. Any animal as large as they are or smaller are potential prey, caught and killed in the typical fashion of stone shrimp. The scooping forelimbs of the fan-tail mantis are also sharp-edged for cutting into flesh and ending in curved hooks for clinging to struggling prey. The scissor-like mandibles of fan-tail mantises then slice into the hide of captured prey, disembowelling them as they writhe about. Other fan-tailed mantises close by may also be drawn in and cut away pieces from the victim, resulting in the animal being torn apart while it is still alive. Inversely, this freeloading has accidentally caused more than a few fan-tail mantises to lose their catch, as they begin to squabble amongst one another and drop the prey, allowing it a chance to escape. Bladder fungi may also be consumed occasionally.

Although tolerant of one another most of the time, a particularly large carcass or kill spurs on the onset of mating, as it inevitably attracts most fan-tails in the vicinity. This will also feed most fan-tails in the vicinity as well, so with their minds off of food, they can attend to the prospect of mating without the possibility that a potential mate may try and eat them. The trigger for courtship begins when once male begins to display, which begins a positive feedback loop, as more males respond with their own displays. Within hours of this, dozens of fan-tails will have structured a layered lekking ring as each male hurries to find the best prospective display patch. Males will fight one another for the best spots, but these are largely bluff; although it was previously believed they would violently brawl should display alone not be sufficient, later study has indicated that these were largely mock battles meant to entice females through a show of physical strength. Males perform a complex dance where they rapidly scurry from side to side and flick their glowing tails open and closed, while occasionally tapping the ground with their forearms. Injuries and malformations are also judged, and fan-tails, until boulder mantises or stalagmite crabs, will remove any fungal growth that accumulates on their shells.

Females usually mate with several males before the courtship ring disperses as the mantises start to get hungry again. Because of the unpredictability of another carcass of sufficient size to begin courtship to appear again, females produce a large number of eggs in each clutch (usually between one to two hundred) and are larger than males to be able to produce such an amount of eggs at once (males average around twenty-five centimetres in height, while females often exceed thirty centimetres and reach a third greater in weight than the average male fan-tail). Fan-tail mantises bury their eggs and once they hatch, the young fan-tails are left to fend for themselves immediately. Adults of this species are not cannibalistic against their young, as they appear to release a pheromone that pacifies adult fan-tails. This being an adaptation lacking in other stone shrimp species, as the unique breeding habits of the fan-tail mantis necessitating that they try and reduce infant mortality as much as possible. Many fan-tail mantis juveniles will associate with adults, and will often feed upon the scraps of their meals or learn where algae/fungus patches are most prevalent; the adults generally ignore them, which is more than can be said for other tectopetracarian species.

(Fan-tails are the most common stone shrimp species displayed in captivity, for their grazing habits make them comparatively more active and mobile than other tectopetracarians, making them more enjoyable to observe. Their colourful posterior flaps and relatively small size also makes them more attractive for viewers while not requiring as much space to house them. However, this smaller size is also deceptive, for the fan-tail mantis is just as aggressive as its larger relatives and capable of injuries that require medical attention; thick gloves are an almost required item when interacting with them. Their scalpel-sharp forearms are capable of lashing out faster than the eye can see and scooping out a small chunk of flesh.)