“It was a night dive on the wall, and I was busy scanning the rocks and coral illuminated by my dive light’s narrow beam, when my dive master frantically points out a small orange/red clam like creature attached to the wall. Upon closer inspection I was simply mesmerized. The clam had red tentacles through which a blue bolt of electricity seemed to be flashing across back and forth like a tiny lightning bolt that burned bright blue in the darkness. I simply couldn’t take my eyes off this creature.”
The “clam” that the diver above is referring to is actually known as The Electric Flame Scallop, also called the Red Electric Flame Scallop or scientifically known as Lima Sp. Belonging to mollusk family known as Limidae which comprises of only bivalve mollusks which are made up of scallops, clams, oysters and mussels that have a shell consisting of two rounded plates called valves joined at one edge by a flexible ligament or hinge.
The Electric Flame Scallop, inhabits the waters of the Indo-Pacific, ranges in size from 1 inch to 3 inches when reaching maturity and is instantly recognizable by its soft parts being a flame red color, with several bright red tentacles protruding from the open valves (shell). What makes this creature even more fascinating is that it seems to create bluish white electricity which can be seen shooting across the mantel like lightning bolts quite visibly in the dark.
While the purpose of the Electricity generated by this creature is unknown, it makes a remarkable spectacle for any night dive where even in the darkness; you can see the flicker of bluish electricity bolts flowing through the scallop’s filaments. For Underwater photography an electric flame scallop is truly a delight to photograph. During the day, the bio-luminescence isn’t very apparent, which is why electric scallop sightings are more spectacular at night.
The electricity (which is actually a form of bioluminescence) is not known to be harmful to divers or other creatures, and especially since the electric flame scallop is a filter feeder and feeds off on microscopic phytoplankton and bacterioplankton (omnivorous) it is curious why it possesses such a brilliant ability. Marine Biologists suggest that the light generated by the electric scallop attracts plankton to its filament like tentacles helping it feed from a fixed location.
Often the Electric Flame Scallop is confused with its parent species the Flame Scallop or Lima Scabra which is also similar in appearance, with a red fleshy mantle covered with tentacles, except for the absence of the strip of bio-luminescent tissue on its mantle that sends a flash of color back and forth over the mantle. Interestingly enough the Flame Scallop, and it’s sub-species the Electric Flame Scallop are not truly scallops but a form of file-clam.