An unlimited breeding colony of a fish species referred to as the Jonah’s icefish (Neopagetopsis ionah) has been found within the southern Weddell Sea, Antarctica.
The nests of the Jonah’s icefish (Neopagetopsis ionah) within the Weddell Sea, Antarctica. Image credit score: Purser et al., doi: 10.1016/j.cub.2021.12.022.
The Jonah’s icefish is a species of notothenioid fish within the household Channichthyidae (crocodile icefishes).
First described in 1947 by the Swedish ichthyologist Orvar Nybelin, it belongs to the monotypic genus Neopagetopsis.
The species is discovered within the Southern Ocean at depths of from 20 to 900 m.
In February 2021, a crew of researchers aboard the German analysis vessel Polarstern noticed quite a few nests of the Jonah’s icefish on the seafloor of the Antarctic Weddell Sea.
“The unique observations were made with the Ocean Floor Observation and Bathymetry System (OFOBS),” mentioned Autun Purser, a marine biologist with the Alfred Wegener Institute on the Helmholtz Centre for Polar and Marine Research.
“It is a camera sledge built to survey the seafloor of extreme environments, like ice-covered seas.”
“It is towed on a special fiber-optic and power cable normally at a speed of about one half to one knot, about 1.5 m above the seafloor.”
The colony was estimated to cowl at the least 240 km2 of the japanese flank of the Filchner Trough, comprised of fish nests at a density of 0.26 nests per m2.
It represents an estimated whole of 60 million lively nests and related fish biomass of over 60,000 tons.
The majority of nests had been every occupied by one grownup icefish guarding 1,735 eggs.
“The idea that such a huge breeding area of icefish in the Weddell Sea was previously undiscovered is totally fascinating,” Purser mentioned.
“After all, the Alfred Wegener Institute has been exploring the area with its icebreaker Polarstern since the early 1980s.”
“So far, only individual Neopagetopsis ionah or small clusters of nests have been detected here.”
According to the crew, it’s the most spatially expansive steady fish breeding colony found to this point globally at any depth, in addition to an exceptionally excessive Antarctic seafloor biomass.
“After the spectacular discovery of the many fish nests, we thought about a strategy on board to find out how large the breeding area was — there was literally no end in sight,” Purser mentioned.
“The nests are three quarters of a meter in diameter — so they are much larger than the structures and creatures, some of which are only centimeters in size, that we normally detect with the OFOBS system.”
“So, we were able to increase the height above ground to about 3 m and the towing speed to a maximum of three knots, thus multiplying the area investigated.”
“We covered an area of 45,600 m2 and counted an incredible 16,160 fish nests on the photo and video footage.”
A paper describing the invention was printed within the journal Current Biology.
_____
Autun Purser et al. An unlimited icefish breeding colony found within the Antarctic. Current Biology, printed on-line January 13, 2022; doi: 10.1016/j.cub.2021.12.022