Beware the Electric Fish!
Remember being scolded as a kid for trying to plug in something with wet hands? That's because water conducts electricity. So what happens in the ocean when you encounter a strange fish capable of delivering a 200-volt electric shock? You might imagine that the underwater world insulates you from electric currents, but think again.
Deep at the bottom of the sea dwells a truly fascinating and unusual creature—the torpedo ray, a member of the electric rays family. Few have had close encounters with this fish, which some call the sapphire torpedo due to its flat shape that resembles a paddle decked with sapphires. Its body is flat, with fins extended like wings, and its width matches its length, giving it a squarish form that it propels using its fins. However, unlike wings that move up and down, these fins move forward and backward.
These fins allow it to dart or bury itself rapidly when needed, a unique trait. This movement resembles the airborne gliding reminiscent of certain soaring fish. Its pectoral fins form a sort of rounded, flat, thick disc resembling a club, with a short, thick, muscular tail and smooth skin.
Electric Shock
The torpedo ray isn’t the only member of its family. Others include the electric nut and manta ray. Despite some differences, they share a great similarity in appearance and behavior—their electrifying abilities. Whenever they seek prey or need defense, they emit a current in the desired direction, efficiently achieving their goal.
The torpedo ray delivers the strongest jolt. Its chest fins’ muscles are electric organs capable of generating up to 200 volts, courtesy of special batteries within its body. One shock incapacitates its foe, allowing the ray to leisurely settle down and swallow it. The torpedo ray comfortably resides at depths of 200 to 400 meters on the sea floor, be it sandy or muddy.
The torpedo ray, along with the electric nut and manta, showcase several interesting differences from the commonly known fish species. For one, they lack a bone skeleton, having a cartilage-filled arch-like body instead. Furthermore, in contrast to the two breathing slits found in most fish, the "electric" ones have between five and seven pairs of gill openings for breathing. These fish have two eyes deeply set close together on the top of their heads. Their nostrils, located on the lower body, appear eye-like but function as tasting openings through which the fish sample their food. Their diet mainly consists of small sea creatures, crab, snails, and small fish.
These "electric" creatures primarily inhabit shallow waters close to the shoreline, camouflage themselves by embedding into the muddy ground. Yet, it's worth mentioning that the giant manta behaves differently from its family; while others spend long hours camouflaged on the sea bed, the giant manta swims near the surface for extended periods.
The manta ray is a giant fish with a vast wingspan. Named manta for its black cloak-like upper side, protruding lobes above its head create an imposing appearance. These lobes funnel water into its mouth while swimming powerfully using "wings" [its pectoral fins].
The water that passes through its mouth contains tiny creatures known as plankton. Its mouth filters water through gill rakes, directing these small creatures right to its stomach. Occasionally, it swallows larger creatures, like fish, squids, and shrimp.
Despite its frightening appearance, it poses no threat to humans unless approached recklessly.
An Egg Anchored Down
One of the most fascinating aspects of the "electric" creatures’ lives is how the female lays her eggs. Unlike most fish that release eggs directly into the water, these eggs are ejected enclosed in boxes or black cases made from a flexible, rubber-like material. Each square box, about 3.5 cm in diameter, has four corners, two on each side. These corners resemble horns, to which threads are attached, each ending in a sort of hook that anchors into the sea bottom, acting like an "anchor". This secures the egg case from being swept away by stormy waves. Nonetheless, strong gales sometimes wash these "black boxes" ashore.
The egg "incubation" inside the black box lasts around three weeks. Then, the tiny fish must emerge. To start breathing, it needs water. Right on time, usually on the 20th or 21st day of incubation, small holes open at the ends of the black box. Water enters, allowing the little fish to breathe. This is a critical moment as the fish begins its life: if the openings occur too early, it risks death before ready to face "the world". Conversely, if they open too late, it might suffocate in its sealed space without air. This timing is one of nature's incredible wonders.
Another marvel is that the openings appear opposite the "anchor" threads’ side of the black box, preventing the emerging fish from tangling. The little fish comes out with its "wings", or fins, folded. When spread, the fins are three times wider than its incubation cell. Naturalists have discovered that these openings of the black box react precisely when the yolk's stored food depletes and the little fish must emerge to find both respiration and nourishment in the open sea. Once everything is aligned, the cell opens, and the little fish swims away, exactly like a "fish in water".
