This freshwater decapod crustacean is distinguished by its subcircular and highly convex carapace. The dorsal surface features a striking coloration that varies from bright red to reddish-brown, which becomes more pronounced in mature specimens. The anterolateral margin of the shell is armed with five to seven sharp spines, excluding the outer orbital angle. Its chelipeds (claws) are asymmetrical, particularly in males, exhibiting a distinct heterochely with one claw being significantly larger, robust, and colored in a vibrant crimson. The walking legs (pereiopods) are slender, with the margins of the dactyli fringed with dense setae, a specialized morphological adaptation that aids in swimming and navigating muddy substrates. In adult specimens, the carapace width typically ranges between 45 and 60 millimeters.

Geographical distribution The species is widely distributed across major river basins of South America, including the Amazon basin, the Paraná-Paraguay system, and the Araguaia-Tocantins basin. Its presence has been extensively recorded in several states of Brazil (such as Mato Grosso, Mato Grosso do Sul, São Paulo, and Minas Gerais), eastern Bolivia, the Chaco region of Paraguay, and northeastern Argentina, particularly in the provinces of Formosa, Chaco, Corrientes, and Santa Fe.

Habitat: It primarily inhabits lentic and slow-moving freshwater environments, such as permanent lagoons, marshes, flooded savannas (including the Pantanal and Iberá Wetlands), and quiet river banks. It shows a strong affinity for floating aquatic vegetation, especially the root systems of macrophytes belonging to the genus Eichhornia (water hyacinths), which serve as critical foraging areas and shelter from predators. It thrives in muddy or clayey substrates where it can easily burrow.

Feeding It is an opportunistic omnivore with a highly varied diet. A significant portion of its food intake consists of organic detritus, decomposing plant matter, and aquatic macrophytes. It also actively preys upon small aquatic organisms, including insect larvae, small gastropods, microcrustaceans, and carrion. This feeding behavior plays an essential ecological role in nutrient cycling within its freshwater ecosystems.

Behavior: It exhibits predominantly crepuscular and nocturnal habits, spending daylight hours hidden beneath dense mats of floating vegetation or buried deep within the mud. The species possesses a remarkable capacity for bimodal respiration, allowing it to utilize atmospheric oxygen and survive outside water in humid microhabitats. During dry seasons, it excavates deep burrows into moist riverbanks to prevent desiccation.

Reproduction Unlike marine decapods, this species exhibits abbreviated direct development, an evolutionary adaptation to freshwater environments that bypasses the free-swimming zoea and megalopa larval stages. Females produce a small number of large, yolk-rich lecithotrophic eggs which they carry and protect under their folded abdomen. Upon hatching, the young emerge as fully formed miniature crabs and remain attached to the mother´s pleopods for several weeks, benefiting from extended maternal care before dispersing.

Conservation status It is currently categorized as Least Concern (LC) on the IUCN Red List, owing to its broad geographic range and high population density in undisturbed habitats. However, local populations are increasingly threatened by habitat degradation, agricultural runoff containing pesticides and fertilizers, and hydrological alterations caused by dam constructions and land reclamation.