Pin Shell Scallop

The Caribbean Pin Shell Scallop (Atrina rigida) is a unique and elegant bivalve that brings a natural reef-flat look to saltwater aquariums. With its elongated, triangular shell and subtle tan to brown coloration, this species adds texture and interest without overpowering the rest of the tank. When settled, it often displays delicate mantle edges that gently extend from the shell, giving it a quiet but fascinating presence.

Native to shallow Caribbean waters, the Pin Shell Scallop naturally anchors itself upright in sandy or muddy substrates. In the aquarium, it does best when partially buried in fine sand with stable water conditions and low disturbance. This is a stationary invertebrate once established, making placement important during acclimation.

The Caribbean Pin Shell Scallop is completely reef safe and will not harm corals, fish, or other invertebrates. It is a filter feeder and relies on suspended micro-foods for nutrition, including live or preserved phytoplankton. Because it does not move to seek food, a well-maintained system with regular target or broadcast feeding is essential for long-term success.

This species is best suited for experienced aquarists who understand the needs of filter-feeding invertebrates. With proper care, stable parameters, and consistent feeding, the Pin Shell Scallop can be a rewarding and visually distinctive addition to a peaceful reef or lagoon-style aquarium.

Quick Facts:

Care Level: Moderate to Advanced
Temperament: Peaceful
Maximum Size: ~8–12 inches (shell length)
Minimum Tank Size: 30 gallons
Diet: Filter Feeder (phytoplankton and suspended micro-foods)
Reef Safe: Yes

If you’re looking to add a natural, understated invertebrate that enhances the realism of your reef environment, the Caribbean Pin Shell Scallop is a beautiful and intriguing choice.