Shark populations in the Mediterranean are highly divided, an international team of scientists, led by Dr Andrew Griffiths of the University of Bristol, has shown.
Many previous studies on sharks suggest they move over large distances. But catsharks in the Mediterranean Sea appear to move and migrate much less, as revealed by this study. This could have important implications for conserving and managing sharks more widely, suggesting they may be more vulnerable to over-fishing than previously thought.
The study, published in the new journal Royal Society Open Science, used genetic techniques to investigate the population structure of the small-spotted shark, Scyliorhinus canicula. The species is common throughout Europe and has been eaten since ancient times, as documented in Roman mosaics.
In the UK anglers catch it for sport and it can often be seen in rock pools at low tide. The study found evidence of isolated populations in the Mediterranean, but no population division was found between catsharks around the North East Atlantic and British Isles.
During the last ice age, about 20,000 years ago, ice sheets occupied much of the Seas and Ocean of this region and catsharks probably didn't survive in the area. This means the region had to be recolonised, and there are very little genetic differences between them today.
The study also highlights differences in the movements of males and female catsharks - an increasingly common finding in sharks.
Dr Griffiths, based in the School of Biological Sciences, said: "It makes a lot of sense, females may want to stay in areas that are good for laying eggs, but males are often the dispersing sex, perhaps taking risks to increase how much they reproduce."
This research has conservation implications; if patterns of population structure vary hugely in different seas, and between the sexes, then shark resilience to fishing can vary greatly, meaning that better informed management could be needed for many species.
'A tale of two seas: contrasting patterns of population structure in the small-spotted catshark across Europe' by Gubili C et al in Royal Society Open Science.
Hannah Johnson | EurekAlert!
Diving robots find Antarctic winter seas exhale surprising amounts of carbon dioxide
15.08.2018 | University of Washington
Algorithm provides early warning system for tracking groundwater contamination
14.08.2018 | DOE/Lawrence Berkeley National Laboratory
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
15.08.2018 | Physics and Astronomy
15.08.2018 | Earth Sciences
15.08.2018 | Physics and Astronomy