species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
bivalve
Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed b ...
mollusk
Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...
in the
family
Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
Limidae
The Limidae or file shells are members of the only family of bivalve molluscs in the order Limida. The family includes 130 living species, assigned to 10 genera. Widely distributed in all seas from shallow to deep waters, the species are usually ...
, the file clams. It is known by the names electric flame scallop, disco scallop, electric clam and disco clam. The clam has been given these nicknames because its soft tissues flash light like a
disco ball
A disco ball (also known as a mirror ball or glitter ball) is a roughly sphere, spherical object that reflects light directed at it in many directions, producing a complex display. Its surface consists of hundreds or thousands of facets, nearl ...
. Along with '' Ctenoides scaber'', they are among the only bivalves known to have light displays.
The electric clam is widespread throughout the
tropical
The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...
waters of the central
Indo-Pacific
The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...
region from
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...
to
Palau Islands
Palau, officially the Republic of Palau, is an island country in the Micronesia subregion of Oceania in the western Pacific Ocean. The Republic of Palau consists of approximately 340 islands and is the western part of the Caroline Islands, w ...
and
New-Caledonia
New Caledonia ( ; ) is a group of islands in the southwest Pacific Ocean, southwest of Vanuatu and east of Australia. Located from Metropolitan France, it forms a ''sui generis'' collectivity of the French Republic, a legal status unique ...
.
Research by graduate student Lindsey Dougherty showed that the apparent flashing-light display of this clam is not a
bioluminescence
Bioluminescence is the emission of light during a chemiluminescence reaction by living organisms. Bioluminescence occurs in multifarious organisms ranging from marine vertebrates and invertebrates, as well as in some Fungus, fungi, microorgani ...
phenomenon, but is instead coming from reflection of the ambient light (sun or diving light). A staff member of the
Lembeh
Lembeh is an island off the north east coast of Sulawesi near the city of Bitung.
Lembeh Island is 25 km long and 2 km wide. Lembeh Island is separated from the mainland of Sulawesi by a narrow stretch of water known as the Lembeh Stra ...
Resort in Indonesia, where Dougherty was working with Dimpy Jacobs in August 2013, wrote, "The clams have a highly reflective tissue on the very outer edge of their mantle that is exposed and then hidden very quickly, so the change back and forth from the white reflective tissue to the red tissue creates the appearance of flashing".
Dougherty went on to discover that the brightly reflective edge of the mantle of these clams contains nanospheres made of
silica
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and abundant f ...
, which are very reflective.
In 2016, Dougherty published another study of ''C. ales'' that suggested the flashing behavior was most likely developed for the purpose of predator deterrence.