Pectinida

Pectinida is an order of marine bivalve molluscs commonly known as scallops and their allies. These bivalves are characterized by their fan-shaped shells, which are typically equivalve (both valves are the same size) or nearly so, and often exhibit radial ribs. A distinctive feature of many pectinids is their ability to swim by rapidly clapping their valves together, expelling water and propelling themselves through the water column. This mode of locomotion is primarily used to escape predators.

The order Pectinida is divided into several families, including the Pectinidae, which contains the familiar scallops, and the Amusiidae. Members of this order inhabit a wide range of marine environments, from shallow coastal waters to the deep sea, and are found in all the world's oceans. Their diet consists of plankton and other small organic particles filtered from the water. Many species are commercially important as a food source. Pectinids have a unique sensory apparatus along the edge of their mantle, including numerous simple eyes that can detect changes in light intensity and movement, aiding in predator avoidance.