Climate change makes sharks & # 39; right-handed & # 39 ;: rising ocean temperatures affect the direction in which they swim, study finds
- Australian scientists have incubated eggs at temperatures predicted for 2100
- They found that half died within a month, and those who survived were left-handed & # 39; and preferred swimming to the right
Mark Prigg for Dailymail.com
Warming oceans are changing the way sharks swim – and making them right-handed, researchers have discovered.
Australian scientists incubated eggs in heated tanks to simulate temperature changes at the end of the century.
They found death within half a month and those who survived were right handed & # 39 ;, and preferred swimming to the right, a process known as lateralisation.
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Australian scientists found sharks that were incubated in tanks that simulate temperatures in 2100 & right hand & # 39; were, and preferred to swim to the right, a process known as lateralisation
The researchers discovered that the rising temperatures developed the property much faster than expected.
& # 39; We have incubated the sharks of Port Jackson and raised them against the current and projected temperatures at the end of the century and sizes from left or right to measure the preference, & # 39; the researchers wrote in a study published in the journal Symmetry.
To test whether the sharks had developed lateralization, the team placed them in a long tank with a Y-shaped dividing wall at one end.
Behind the divorce was a reward for food; sharks simply had to decide if they wanted to swim to the right or left side of the Y to get their snack.
Sharks incubated at elevated temperatures showed a stronger absolute laterality and were significantly biased to the right compared to sharks bred at the current temperature. & # 39;
The researchers say that the changes show that climate change can have a much larger and faster effect on the marine brain than expected.
& # 39; Climate change warms the oceans of the world at an unprecedented rate, & # 39; they wrote.
Under predicted temperatures at the end of the century, many teleosts show a disturbed development and changed critical behavior, including behavioral lateralisation.
& # 39; Because laterality is an expression of brain functional asymmetries, changes in the strength and direction of lateralization suggest that rapid warming may influence the development and function of the brain. & # 39;
Researchers collected a portion of Port Jackson shark eggs from the waters of East Australia.
They incubated 12 eggs in a tank warmed up to the current ambient temperature of the bay (about 70 degrees Fahrenheit, or 20.6 degrees Celsius) and 12 others in a tank that was gradually heated to 74.5 degrees F (23.6 degrees C) to simulate the predicted simulations. simulate. Ocean temperatures in the end of the century.
Five sharks incubated in the elevated temperatures died within a month of hatching.
HAVE THEM BEST FRIENDS?
For the first time, researchers have shown that sharks have very strong preferences over the years for certain individuals in their social networks, and that they prefer to hang around with others of the same sex and size.
The study, which involved the tagging of Port Jackson sharks (Heterodontus portusjacksoni), was carried out at Jervis Bay in New South Wales, Australia.
The bay was chosen because it houses large seasonal mating aggregates of Port Jackson sharks, a soil-type species that is endemic in Australia, where both males and females migrate each year from their foraging area in South Australia to return to the same reef. in Jervis Bay to breed.
Locations of acoustic receivers used in Jervis Bay (NSW, Australia); each circle represents a receiver
Proximity loggers were connected to seven individual sharks in 2012, and acoustic receivers, which were either attached to the seabed, or to mooring lines in the middle of the water, allowing remote monitoring of life in three dimensions, were and 2013 deployed.
The researchers discovered that when the sharks return to their breeding reefs, they do so with incredible accuracy.
The Fish Lab at Macquarie University studies these social interactions with sharks by using acoustic tags that identify individual animals when they are within reach of a recipient.
By analyzing the timestamps of these recipients, the researchers can see who is hanging out with whom and for how long.