"The shell of the scallop is opened and closed by a single large muscle, the adductor muscle, which is used as food in the US. The mantle bears numerous irridescent, primitive eyes, sensitive to changes in light intensity, along a fold on its border, called the velar fold." (1)
The scallop does not usually attach to anything. It actually can swim by rapidly opening and closing its shell. They can also use this technique to squirt water at a possible threat or scare a possible predator away. Scallops are hermaphroditic--they have both female and male sex organs.
(1) "Scallop", Microsoft Encarta 96 Encyclopedia. 1993-1995 Microsoft Co.
