Locustai (Low-Cust-Eye)

Locustai are a race of large, crab-like arthropods. Like other large accroseptulents on Yull, they have both an endoskeleton and exoskeleton to support their sizable bodies. They are highly intelligent, capable of using tools, farming plants and algae and communicating extremely effectively among themselves through sounds and movements. Locustai have ten legs, of which the front two pairs are armed with pincers. The back four pairs have lobes like fins on the trailing edge, allowing the creatures to swim quickly despite their bulk. The colors of locustai shells very with the region in which they live (see fig. C). The shells often have greenish edges an a large stain of color in the middle. Locustai shells are thick and very heavy, and grow with their owners so that molting is unnecessary. Shells are difgficult to obtain, however, because locustai keep others away from their dead and it is considered a crime to attack such an intelligent creature.
Locustai can somehow sense direction on Yull without the veins (see Mapping Yull), and each of the largest groups alternates between to feeding grounds, allowing one to restock its resources while they feast at another. They eat mostly plantss, rotting material, algae and stone, though the latter is mostly for minerals. They have small mouths and often crush larger reeds and other food items with their sharp and incredibly powerful front chelipeds (claws) before eating them.
Locustai and their relative have existed on yull for hundreds of millions of years, with fossils dating back to -253MAB having been found.