A mysterious barrier in the Atlantic divides weird deep-sea jellyfish cousins
A mysterious ocean barrier prevents high -sea jellyfish in the Arctic from reaching the Atlantic Ocean, revealed a new study.
Animals, members of the subspecies of Medusa Botrynema Brucei EllinoraeDwell in depths between 3,300 and 6,600 feet (1,000 to 2,000 meters) and can be divided into two groups depending on whether the individual specimens have a button on their bell structure in the shape of a umbrella.
“This jellyfish […] Has two different shapes depending on the area in which it occurs – one with a distinctive button at the top and one without ” Javier MontenegroA biologist at the University of Western Australia, said in a statement.
The anatomy of the marine creature in a way influences its global distribution: the jellyfish with the distinctive button live through all the oceans and the latitudes, while those who have no button have never been documented only in the Arctic and the Sub-Arctique, said Montenegro.
For the study, Montenegro and its colleagues examined the observational and photographic archives of B. Brucei Ellinorae come back over 120 years. The researchers then mapped the distribution of subspecies of jellyfish by combining these recordings with genetic analyzes. They published their results in the online version of the journal Deep sea research July 3.
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Genetic data said that samples of B. Brucei Ellinorae With and without buttons in the Arctic and the Sub-Arctique were almost identical to specimens with pimples in the Western Atlantic. This suggested that, despite strong genetic similarities, the jellyfish without information could not leave freezing waters.
So how does the shape of the animal determine its distribution? It seems that access to the Atlantic is blocked by a barrier – not by a physical, but biological obstacle, or determined by local geography.
“The differences in form, despite strong genetic similarities between specimens, above and below 47 degrees to the north, refer to the existence of an unknown bio-geographic barrier in the Atlantic Ocean,” said Montenegro.
This barrier is located inside the drift of the North Atlantic, a hot ocean current which extends towards the north of Gulf Stream, but it is not clear if the current itself is the obstacle for jellyfish without renown. A possible explanation could be that there are predators who hide beyond the drift of the North Atlantic that the frosts without information are not equipped to escape – but why having a button can be advantageous is not clear.
The barrier “could keep the specimens without button confined to the north while allowing the free transit of specimens with a button further south,” said Montenegro.
No barrier of this type is required to keep the nodes B. Brucei Ellinorae In the arctic waters on the side of the Pacific Ocean, because the Strait of Bering already blocks most of the high -high creatures to move south, according to the study. The strait is only 165 feet (50 m) deep, therefore jellyfish on the high seas like B. Brucei Ellinorae I can’t cross it.
The discovery of a potential ocean barrier associated with the drift of the North Atlantic is important, because it could help scientists better understand evolutionary relationships and dispersion patterns. “The presence of two samples with distinct forms within a single genetic line highlights the need to study more on the biodiversity of gelatinous marine animals,” said Montenegro.
