The Lanternfish Family – Myctophidae
Panama Lanternfish, Benthosema panamense, a representative member of the Lanternfish or Myctophidae Family.
The Lanternfish belong to the Myctophidae Family and are known as linternillas in Mexico. They are some of the most populous fish in the open ocean with two hundred forty-eight species that have been placed in thirty-three genera and are found globally in all oceanic waters. Their common name is derived from their ability to produce light. They make up at least half of the oceanic fish larvae and adults comprise about two-thirds of all oceanic fish with their global mass estimated at six hundred million tons.
The Lanternfish have slender compressed bodies and are generally small in stature ranging from 2.0 cm (0.8 inches) to 30 cm (12 inches) in length. Shallow water species have an iridescent blue-green silvery color, while deeper water species are dark brown to black. They have a bluntly rounded head with very large eyes that are set close to the tip of their blunt snout. They have a large oblique terminal mouth that extends beyond the eyes and is equipped with close set rows of small teeth. They have small fins that lack spines. Their anal fin originates under or slightly behind the dorsal fin; their caudal fin is deeply forked; their dorsal fin has a short base, is high on the body, and followed by a very small adipose fin. All Lanternfish have a series of luminous and round kidney-shaped organs (photophores) on their head and trunk. Additional photophores of various shapes and sizes are present on their head and caudal fin base. They emit a weak blue, green, or yellowish light along the sides of their body with the specific patterns and shapes being a key to the differentiation of the various fish. These photophores can be turned “on” and “off” and play an important role in communication and for camouflage as the brightness of the bluish light emitted can be regulated to match the ambient light level above masking their silhouette when viewed from below. Males and females of the same species can have photophores in different locations and with different light intensities. They have well-developed gill rakers. Their bodies are covered with small scales and they have complete lateral lines.
Most Lanternfish are coastal residents found in large schools over the continental slope. They make extensive daily vertical migrations; they are found at depths between 1,000 and 3,800 feet during the day to avoid predation and move between below the surface and 330 feet during the night for feeding. They are microcarnivores feeding on amphipods, copepods, euphausiids, and ostracods. In turn they are preyed upon by a wide variety of fish (salmon, sharks, and tuna), marine mammals (dolphins and whales), various sea birds, and squid. Their large schools have raised havoc with sonar scans giving the impression of false bottoms that move up and down in twenty-four-hour cycles.
From a conservation perspective the Lanternfish have recently been discovered as a viable source of animal protein. With the continuing global demise of marine fisheries these pivotal elements of the oceanic food chains are at risk and dire consequences are inevitable. They date from the Miocene Period, approximately fifteen million years ago.
There are four members of the Lanternfish, all from the Pacific, presented in this website: