Natures wonders: clustered icefish nests (Introduction)

by David Turell , Thursday, January 13, 2022, 18:36 (834 days ago) @ David Turell

A large group under Antarctica ice:

https://www.sciencenews.org/article/ice-fish-nest-antarctica-breeding-colony-largest-group

"Five hundred meters below the ice covering Antarctica’s Weddell Sea sits the world’s largest known colony of breeding fish, a new study finds.

"An estimated 60 million active nests of a type of icefish stretch across at least 240 square kilometers, nearly the size of Orlando, Fla. Many fish create nests, from freshwater cichlids to artistically inclined pufferfish (SN: 10/13/20). But until now, researchers have encountered only a handful of icefish nests at a time, or perhaps several dozen. Even the most gregarious nest-building fish species were previously known to gather only in the hundreds.

"The icefish probably have a substantial and previously unknown influence on Antarctic food webs, researchers report January 13 in Current Biology. (my bold)

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"At one location on the Filchner ice shelf in the Weddell Sea, one of Purser’s colleagues was operating the camera tow and noticed that it kept encountering circular Jonah’s icefish (Neopagetopsis ionah) nests down below. Icefish, of the family Channichthyidae, are only found in the Southern Ocean and Antarctic waters and have strange adaptations to the extreme cold such as clear blood full of antifreeze compounds. (my bold)

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"It’s not clear why so many icefish are gathering in one spot to breed. There appears to be good access to plankton in this location, which would be a crucial food source for newly hatched fish. The team also found a zone with slightly warmer water in the area, which could help the icefish locate the breeding ground.

"The icefish could be sustaining Weddell seals, the researchers say. Prior studies have shown the seals spending a lot of time diving in waters above the colony area.

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“'I would say [the massive colony] is almost a new seafloor ecosystem type,” Purser says. “It’s really surprising that it has never been seen before.'”

Comment: not surprising. Life can live anywhere and set up ecosystems for food supply.