Rare deep-sea anglerfish seen for first time in broad daylight
Researchers working on a shark research campaign for the NGO Condrik were surprised by an unexpected visitor off the coast of Tenerife last week, sparking excitement from marine biologists around the world.
Usually found at depths of between 200 and 2,000 metres, an adult abyssal humpback anglerfish or Melanocetus johnsonii was seen near the surface in what might be the first-ever sighting of the species in broad daylight.
Previous sightings have been limited to submarine images, dead individuals or larvae.
Just 2 kilometres off the coast of Tenerife, the underwater photographer David Jara Boguñá first spotted the otherworldly deep-sea fish.
Researchers haven’t determined why this fish showed up near the surface, but some scientists speculate that some individuals of the species sometimes rise up to the surface during the El Niño weather event which reduces the amount of cold water upwelling off the coast of North America.
Marine biologist Laia Valor who was also part of the shark expedition, told the EFE news agency: “We were returning to port when I saw something black in the water that didn’t look like plastic or debris. It seemed unusual. We spent a couple of hours with it. It was in poor condition and only survived for a few hours.”
She added: “There could be thousands of reasons why it was there.
“We simply don’t know. It’s an extremely rare and isolated sighting. While we can’t say it never happens, if it were more common, we would see it more frequently. This could very well be the first time it has ever been filmed in these conditions.”
After the fish passed away, the researchers brought it to the Museum of Nature and Archaeology (MUNA) in Santa Cruz de Tenerife where the body will be studied further to advance knowledge about this elusive species.
Despite a large mouth full of sharp teeth, the humpback anglerfish sports a bacteria-laden, bioluminescent lure on its head to attract and catch prey in the dark realms it lives in.
About the Anglerfish
The anglerfish are fish of the teleost order Lophiiformes. They are bony fish named for their characteristic mode of predation, in which a modified luminescent fin ray (the esca or illicium) acts as a lure for other fish. The luminescence comes from symbiotic bacteria, which are thought to be acquired from seawater, that dwell in and around the sea.Evolution
The earliest fossils of anglerfish are from the Eocene Monte Bolca formation of Italy, and these already show significant diversification into the modern families that make up the order. Given this, and their close relationship to the Tetraodontiformes, which are known from Cretaceous fossils, they likely originated during the Cretaceous.
Classification
Anglerfishes are classified by the 5th edition of Fishes of the World as set out below into 5 suborders and 18 families. The following taxa have been arranged to show their evolutionary relationships.
Anatomy
All anglerfish are carnivorous and are thus adapted for the capture of prey. Ranging in color from dark gray to dark brown, deep-sea species have large heads that bear enormous, crescent-shaped mouths full of long, fang-like teeth angled inward for efficient prey-grabbing. Their length can vary from 2–18 cm (1–7 in), with a few types getting as large as 100 cm (39 in), but this variation is largely due to sexual dimorphism, with females being much larger than males.[16] Frogfish and other shallow-water anglerfish species are ambush predators, and often appear camouflaged as rocks, sponges or seaweed.
from https://en.wikipedia.org/wiki/Anglerfish and https://oceanographicmagazine.com/news/rare-deep-sea-anglerfish-seen-for-first-time-in-broad-daylight/