Top Shell or Thais Chocolata, is a gastropod mollusk that lives in rocky and stony bottoms, usually between 3m. and 30m. depth, a lesser number may be close to the beach.

Its current distribution is from Paita (Peru) to Valparaiso (Chile) reaches a size of 88.3 cm. This snail is distributed between 5 and 40 m depth, on rocky substrates or small shells and gravel is a species with internal fertilization gonochoric without external evidence of sexual dimorphism during the breeding season, adults gather to form aggregations known as "maicillo".