Curved Heart Shell, Strophocardia megastropha

Curved Heart Shell, Strophocardia megastropha. Shell collected off the beach of Punta Chivato, Baja California Sur, June 2025. Size: 3.5 cm (1.4 inches) x 2.8 cm (1.1 inches) x 1.2 cm (0.5 inches). Collection, photographs and identification courtesy of Colin Campbell, DVM, Punta Chivato.

Curved Heart Shell, Strophocardia megastropha. Shell collected off the beach of Punta Chivato, Baja California Sur, June 2025. Size: 3.7 cm (1.5 inches) x 3.2 cm (1.3 inches) x 1.2 cm (0.5 inches). Collection, photographs and identification courtesy of Colin Campbell, DVM, Punta Chivato.

Curved Heart Shell, Strophocardia megastropha. Shell collected off the beach of Punta Chivato, Baja California Sur, June 2025. Size: 4.5 cm (1.8 inches) x 4.0 cm (1.6 inches) x 1.8 cm (0.7 inches). Collection, photographs and identification courtesy of Colin Campbell, DVM, Punta Chivato.

Curved Heart Shell, Strophocardia megastropha. Shell collected off the beach of Punta Chivato, Baja California Sur, June 2025. Size: 4.8 cm (1.9 inches) x 4.1 cm (1.6 inches) x 1.6 cm (0.6 inches). Collection, photographs and identification courtesy of Colin Campbell, DVM, Punta Chivato.

Curved Heart Shell, Strophocardia megastropha, Fossil. Shell collected off the beach of Punta Chivato, Baja California Sur, December 2025. Size: 29 cm (11 inches) x 29 cm (11 inches) x 12 cm (4.7 inches). Collection, photographs and identification courtesy of Colin Campbell, DVM, Punta Chivato. Identification reconfirmed by Identification courtesy of Dr. Paul Vlentich-Scott, Santa Barbara, California.

Phylogeny: The Curved Heart Shell Strophocardia megastropha (J. E. Gray, 1825) is a member of the Carditidae Family of Little Heart Shells. The Strophocardia Genus is in the subfamily Venericardiinae. The Strophocardia Genus is one of nine genera in the Carditidae Family and this species is the only species in the Strophocardia Genus. The genus name Strophocardia comes from a combination of the Greek words meaning “twisted”, “curved”, or “turned”, and the word for “heart”. The species name megastropha means “big twist” or “big turn” Both names refer to this shell’s curved shape. In Mexico this species is called Concha Corazon Curvado.

Description: Curved Heart Shells are trigonal in outline and inflated in profile. They are much taller than they are wide. The beak is high and curved. These shells are sculpted with 12 to 15 low, broad, rounded, axial ribs, and fine commarginal striae and coarser growth lines. The radial ribs cause deep undulations inside the ventral margin. The hinge plate is broad. These shells may be tan, orange, reddish-brown, or purple in color, usually with white spots, bands, or zigzags. Curved Heart Shells reach a maximum of 5.4 cm (2.1 inches) in height.

Habitat and Distribution: Curved Heart Shells are usually found in rubble, from the intertidal zone to depths of 100 m (328 feet). They are a subtropical to tropical Eastern Pacific species that are found in all Mexican waters of the Pacific Ocean with the exception that they are absent from the west coast of the Baja Peninsula and north of Bahía de Los Ángeles, Baja California, in the Sea of Cortez.

Ecology and Behavior:  Curved Heart Shells are suspension feeders that feed primarily on planktonic algae and suspended organic matter. They are gonochoric and reproduce sexually, through broadcast spawning, with external fertilization. Their engagement in any type of commensal, parasitic, or symbiotic relationship has not been formally documented. From a conservation perspective they have not been formally evaluated. However, they are fairly common with a relatively wide distribution and should be considered to be of Least Concern.

Synonyms: Cardita megastropha, Cardita tumida, Cardita varia, Venericardia flammea, and Venericardia megastropha.