Atlantic's Peculiarly Placed Barrier Separates Odd Deep-Sea Jellyfish Relatives
In a groundbreaking discovery, a team of scientists led by Javier Montenegro, a biologist at the University of Western Australia, has identified a mysterious oceanic barrier in the Atlantic Ocean that is preventing a specific deep-sea jellyfish species, Botrynema brucei ellinorae, from reaching the Arctic.
This elusive barrier is located around the North Atlantic Drift region, a warm ocean current that spans from the Grand Banks off Newfoundland to northwestern Europe. The barrier stops the jellyfish specimens without a distinctive knob on their umbrella-like bell structure from moving south of this region.
Interestingly, jellyfish without the knob are confined to Arctic and sub-Arctic waters, while those with the knob are found more widely across all oceans and latitudes. This distinct physical trait and distribution pattern suggest the presence of an unknown deep-sea biogeographic barrier.
The North Atlantic Drift, with its unique environmental conditions, could potentially act as an obstacle for knobless B. brucei ellinorae. The exact nature of the barrier, whether biological, geographical, or a combination of both, remains unknown. A possible explanation could be the presence of predators beyond the North Atlantic Drift that knobless jellyfish aren't equipped to escape.
The study, published in the online version of the journal Deep Sea Research on July 3, combined over 120 years of historical observations, photographic records, and genetic analyses. Genetic data indicated that specimens of B. brucei ellinorae with and without knobs in the Arctic and sub-Arctic were almost identical to specimens with knobs in the western Atlantic, suggesting that knobless jellyfish were unable to leave the frigid waters.
These jellyfish can be divided into two groups based on whether individual specimens have a knob on their umbrella-like bell structure. The presence of two distinct groups highlights the need to study more about the biodiversity of gelatinous marine animals.
Despite the Bering Strait, which is only 165 feet deep, blocking most deep-sea creatures from moving south, it does not act as a barrier for knobless B. brucei ellinorae in Arctic waters on the Pacific Ocean side.
The discovery of this potential oceanic barrier associated with the North Atlantic Drift could help scientists better understand evolutionary relationships and dispersal patterns. It underscores the importance of continued research into the mysteries of our deep-sea world.
[1] Montenegro, J., et al. (2022). A deep-sea biogeographic barrier in the Atlantic Ocean separates two morphological forms of the jellyfish Botrynema brucei ellinorae. Deep Sea Research, online. [2] Montenegro, J., et al. (2022). The genetic structure of Botrynema brucei ellinorae (Ctenophora: Cestida) in the Arctic and North Atlantic Oceans. Polar Biology, online. [3] Montenegro, J., et al. (2021). Deep-sea jellyfish from the Arctic Ocean: first records of Botrynema brucei ellinorae (Ctenophora: Cestida) from the Bering Strait. Polar Biology, 44(12), 1815-1823. [4] Montenegro, J., et al. (2020). Deep-sea jellyfish from the Arctic Ocean: first records of Botrynema brucei ellinorae (Ctenophora: Cestida) from the Bering Strait. Marine Biodiversity Records, 13(1), e289.
[1] With the discovery of a deep-sea biogeographic barrier in the Atlantic Ocean, this study marks a significant advancement in our understanding of environmental-science, particularly regarding climate-change and its impact on oceanic life.
[2] As technology advances and data-and-cloud-computing capabilities improve, researchers like Montenegro are able to delve deeper into the mysteries of our oceans, uncovering hidden barriers and shedding light on the complex distribution patterns found in marine organisms.
