Features a solid, wedge-shaped bivalve shell that is highly inequilateral, with a long, rounded anterior end and a short, steeply truncated posterior slope. The external surface is relatively smooth, displaying faint concentric growth lines and delicate radial striae that become more pronounced on the posterior slope. This species is renowned for its remarkable color polymorphism, with shells displaying vivid shades of white, yellow, orange, pink, purple, and brown, frequently embellished with dark concentric bands or radial rays originating from the umbo. The inner margins of the valves are finely crenulated, and the interior often mirrors the exterior´s purple or yellow coloration. Adult specimens typically measure between 15 and 40 millimeters in length, with females often reaching slightly larger dimensions than males.

Geographical distribution: Is endemic to the Southwestern Atlantic Ocean, ranging from the states of Espírito Santo and Rio de Janeiro in Brazil, extending southward along the entire coast of Uruguay, and reaching down to the southern sandy beaches of the Buenos Aires Province in Argentina. Within this region, it represents one of the most abundant macrofaunal components of the sandy beach ecosystem.

Habitat: Resides strictly in the intertidal zone and the active swash zone of microtidal and macrotidal sandy beaches characterized by high wave energy. It exhibits a strong preference for well-sorted, fine to medium quartz sand, where the sediment remains highly saturated and oxygenated by continuous wave action, avoiding low-energy muddy bays or gravel-dominated shores.

Feeding: Functions as an obligate suspension feeder, playing a crucial role in coastal energy transfer. By extending its short, separate inhalant and exhalant siphons into the turbulent water column, it filters out suspended organic matter, targeting phytoplankton, particularly benthic and planktonic diatoms, dinoflagelates, and fine organic detritus suspended by the breaking waves.

Behavior: Exhibits a highly dynamic lifestyle finely tuned to the relentless movement of the surf. It possesses a powerful, wedge-shaped muscular foot that facilitates rapid burrowing into the wet sand within a few seconds, a vital defense mechanism against wave displacement and predators. Furthermore, it undergoes tidal migration, active movements up and down the beach face synchronized with the rising and falling tides, using the physical force of the incoming and outgoing waves to maintain its position in the wet swash zone.

Reproduction: Exhibits a gonochoristic reproductive strategy with separate sexes and no visible sexual dimorphism. Fertilization is external, occurring in the open water column where both males and females release their gametes simultaneously, a phenomenon triggered by seasonal temperature changes and food abundance. Spawning is typically prolonged, with major peaks during the spring and summer months. The resulting offspring develop through a planktonic veliger larva stage, drifting with coastal currents for several weeks before undergoing metamorphosis and settling onto the sandy substrate as recruits.

Conservation status: Has not been globally evaluated by the International Union for Conservation of Nature (IUCN). However, local populations are increasingly threatened by coastal development, beach nourishment, off-road vehicle traffic on dunes and beaches, overharvesting for bait, and climate-induced extreme events such as marine heatwaves and harmful algal blooms.