REP: The Brimstars

Brimstars are members of the Sulphozoa, which is easily the strangest of the three multicellular kingdoms of Red Earth. In contrary to the Panimalia, which developed cell organelles out of their own structures and are therefore more akin to higher organized procaryotes, Sulphozoa have truly eucaryotic cells, created by endosymbiosis with sulphate-reducing microorganisms. This symbiosis is the origin of their sulphur-based metabolism and the reason for their strictly anaerobic habits. Sulphozoa are generally small, slow-growing and pretty much exist in their own food webs, separated from the aerobic lifeforms save for influx of dead matter and the occasional predator. They exist only in the dead zones of marine habitats, spreading and surviving aerobic influxes through resilient spores. Their body plan is fairly simple and often resembles Earth's Vendobionta because of the fractal symmetry; the development of an additional, secondary trilateral symmetry is not uncommon. The single units can be either separated or connected, depending on the mobility and the metabolic needs of the organism.

Brimstars are a fairly common mobile group of Sulphozoa that resemble three-armed starfish. They live on or in the ground where they move around by cilia and feed on microbial mats, detritus or smaller sulphozoans with a few autotrophic forms in between. The central seams on the underside of their arms work as the mouth, leading to a diverticled pocket, from where the single units are able to extract nutrients for further processing. They reproduce by dropping off a piece of an arm, which will look for another brimstar on its own to be consumed by it and take in the gametes it contains. If a broken-off arm is unable to find a mate, it will regenerate into a complete brimstar.

Frilled Brimstar: One of the few autotrophic forms that filter sulphate from the water. For more efficient resorption of nutrients, the units are extended into leaf-like shapes. The brimstar is still capable of moving in search for more nutrient waters.

Fat Brimstar: This short-armed species is comparably fast-moving and preys on other sulphozoans, which it kills by the use of venom.

Sandseal: Being one of the smallest brimstar species, sandseals reduced the number of units per arm to two. Living in between the sand grains, they feed off microorganisms and dead organic matter and can be found in the anaerobic layers of coastal sands.

Silt Arrowhead: This member of a digging, asymmetric group feeds on detritus and the microorganisms that live within it. Some species prey on other burrowing brimstars.

Crawling Brimstar: This group of long-armed forms feed on microbial mats they can efficiently graze on by the large areas they can cover with their arms. They inhabit the sparsely-populated areas and some species have some degree of oxygen tolerance that allows them to live and feed in spaces where predatory sulphozoans can't reach them.