Aura Rupees
The Aura Rupees split from their ancestor. As a defense against predators, they have integrated large amounts of aragonite into their shells, reducing their photosynthesis somewhat but creating an iridescent appearance—almost like some kind of opaque aura quartz. They make full use of their ancestors’ ability to utilize a different photosynthesis pigment in different lighting conditions as well, creating a great rainbow of color varieties for different depth levels, but they predominantly serve as decomposers. Unlike other crystal flora, Aura Rupees which live in areas with no light at all turn an iridescent pearl-like white rather than black.
Though they retain the ability to reproduce waterborne spores, Aura Rupees can also bud from their root system. This allows them to spread quickly over a large meal, such as one left by fallen sea creatures. Oceanic mosshrooms and their relatives lacked this budding ability at the time it evolved, and as such the Aura Rupees have outcompeted the Crustal Gem despite its individual crystals growing more slowly than it.
Having aragonite shells, Aura Rupees are vulnerable to ocean acidification. They cannot reside in any part of the ocean which is naturally more acidic than other areas.
There are many, many species of Aura Rupee. Those in cold regions and deep ocean depths often have thicker shells to protect them from cold and pressure, respectively. Polar species tend to also have darker pigments to get them through the dark winter. Volcanic species have shells even thicker than the others. Though ridge species largely lack photosynthesis, in rare cases where a ridge rises into sunlit regions—such as Rhino Ridge—this is not the case. For example, the Platinum Aura Rupee native to Rhino Ridge sports an incredibly thick, yet still photosynthetic shell. A handful of species reside in hydrothermal vents and on trench floors and the presence of lava glow causes them to develop photosynthetic pigments, but very little photosynthesis actually occurs.