Lanternfish, Deepsea Lanternfish, Rail lanternfish

Lanternfish are small, deep-sea fish known for their bioluminescence. They possess photophores (light-producing organs) distributed along their bodies, creating a striking pattern of glowing spots and lines. This bioluminescence serves various purposes, including attracting prey, confusing predators, and facilitating communication between individuals. They have a streamlined body shape and large eyes adapted for seeing in low-light conditions. There are over 200 recognized species of lanternfish, belonging to the family Myctophidae. They range in size from a few centimeters to around 20 centimeters in length. They have a distinctive, sometimes complex pattern of photophores that often differ between species, serving as a form of species recognition. They are an important component of the deep-sea ecosystem, playing a vital role in the food web.

Lanternfish are predominantly found in the mesopelagic zone (200-1000 meters depth) of oceans worldwide. They inhabit a wide range of oceanic regions, including tropical, subtropical, and temperate waters. Different species exhibit varying depth ranges and geographic distributions. Some species are found closer to shore, while others are exclusively found in the open ocean. They are exceptionally abundant in the deep waters of the Atlantic, Pacific and Indian oceans. They prefer areas with stable temperatures and moderate salinity.

Lanternfish exhibit a fascinating diel vertical migration pattern. During the daylight hours, they descend to the deeper, darker regions of the ocean to avoid predators and conserve energy. As darkness falls, they migrate upwards towards the surface waters to feed on plankton and other small organisms. They reproduce through broadcast spawning, releasing eggs and sperm into the water column. The larval stage is planktonic, drifting in the open ocean. They are preyed upon by larger fish, squid, marine mammals, and seabirds.

Lanternfish are generally not consumed by humans due to their small size, oily nature, and deep-sea origin. They are not commercially fished. While occasionally caught as bycatch in deep-sea fisheries, they are typically discarded. Their flesh is described as being quite oily and not particularly palatable. The oil is sometimes rendered for use in other processes.