The Internet has been buzzing with reports of “the deepest fish ever recorded” this morning! And they look quite sweet to boot:
But are these snailfish really “the deepest fish ever recorded”?! Turns out, that’s quite a complicated question!
CNN writes: “Cruising at a depth of 8,336 meters (over 27,000 feet) just above the seabed, a young snailfish has become the deepest fish ever filmed by scientists during a probe into the abyss of the northern Pacific Ocean.”
As far as I have found, yes, this is the deepest fish ever filmed.
They also write: “Along with the filming the deepest snailfish, the scientists physically caught two other specimens at 8,022 meters and set another record for the deepest catch.”
This statement is wrought with controversy!
In the paper Fishes of the hadal zone including new species, in situ observations and depth records of Liparidae (2016), Linley et al. detail fishes that have been found deep in the ocean.
Abyssobrotula galatheae is generally considered to be the deepest-living fish at a depth of 8,730 meters, which is noteworthy as it was found below the fish sighted on video! However, this is a controversial finding. The specimen was likely collected with an open net, which means there is room for error and the fish could have been caught anywhere above the maximum trawl depth. So, it’s not something we can trust.
CNN: “Previously, the deepest snailfish ever spotted was at 7,703 meters in 2008, while scientists had never been able to collect fish from anywhere below 8,000 meters.”
In the same paper linked above, Linley et al. detail two snailfish species which maximally (as far as we know) live at 8,076 meters deep and 8,145 meters deep! So, the deepest snailfish was described in 2016.
However, the deepest fish Linley et al. actually trapped was found at 7,966 meters deep. So, excluding the Abyssobrotula galatheae specimen, the newly trapped fish(es?) can still be considered the deepest captured specimens.
This discovery is exciting, as the maximum depth for fishes was previously hypothesized to be around 8,200 meters deep (in Yancey et al. 2014)! The sighting of this little snailfish allows us to reevaluate that hypothesis!
I can’t wait to see what we discover next!