Female shark reproduces without sex

Updated on May 23, 2007 07:58 PM IST
An unexpected birth of a shark without sex has led to the conclusion of a possibility of asexual reproduction in sharks.
HT Image
HT Image
AFP | By, Belfast

A female hammerhead shark that gave birth without sex has put the bite into conventional wisdom about reproduction among large vertebrates, according to research published on Wednesday.

The shark's offspring has no paternal DNA, bemused experts from Northern Ireland and the United States report.

The discovery is the first known case of asexual reproduction in sharks but it also raises concerns about the genetic health of dwindling shark populations, they say.

The investigation was launched after an unexpected birth in an aquarium at the Henry Doorly Zoo in Nebraska in December 2001.

The baby's arrival baffled staff, as none of the three possible mother hammerheads in the tank had been exposed to any male hammerhead for the past three years, after they had been caught as babies off Florida.

The research was carried out by scientists from Queen's University Belfast, the Guy Harvey Research Institute at Nova Southeastern University in Florida and the Henry Doorly Zoo.

The head of the Queen's research team and the study's co-author, Paulo Prodohl, from the School of Biological Sciences, described the findings as 'really surprising.'

"As far as anyone knew, all sharks reproduced only sexually by a male and female mating, requiring the embryo to get DNA from both parents for full development, just like in mammals."

Co-author Mahmood Shivji, who led the Guy Harvey Research Institute team, said the research may have solved a mystery about other species of shark having babies in captivity despite not having contact with males.

SHARE THIS ARTICLE ON
Close Story
QUICKREADS

Less time to read?

Try Quickreads

  • Children cool off in a water fountain during a heatwave, in London, Britain. (File)

    Europe's scorching heat to escalate pressure on power infrastructure

    Another scorching heat wave is set to hit northwest and central Europe this week, putting further pressure on the continent's strained power infrastructure. Sizzling temperatures are expected to hit the UK, Germany and France -- reaching almost 36 degrees Celsius (96.8 Fahrenheit) on Friday -- according to Maxar Technologies LLC. The heat will boost demand for cooling, aggravating already dry conditions that hurt crops and force limits on water use.

  • Chinese built Pakistani frigate PNS Taimur at a Cambodian Port. The ship is on a maiden voyage from Shanghai to Karachi.

    Colombo allows Pakistani frigate Taimur to dock, Dhaka says no

    Sri Lanka has allowed permission to the Chinese built-Pakistani guided missile frigate PNS Taimur to make a port call at Colombo while on its way to join the Pakistan Navy in Karachi.

  • United Nations Secretary-General Antonio Guterres. 

    UN chief demands international access to Ukraine nuclear plant after new attack

    U.N. Secretary-General Antonio Guterres called on Monday for international inspectors to be given access to the Zaporizhzhia nuclear plant after Ukraine and Russia traded accusations over the shelling of Europe's largest atomic plant at the weekend. "Any attack (on) a nuclear plant is a suicidal thing," Guterres told a news conference in Japan, where he attended the Hiroshima Peace Memorial Ceremony on Saturday to commemorate the 77th anniversary of the world's first atomic bombing.

  • US President Joe Biden answers a shouted question from a reporter while walking to Marine One on the South Lawn of the White House in Washington, DC, on August 7, 2022, as he travels to Rehoboth Beach, Delaware. 

    US President Joe Biden tread out to find legacy-defining wins

    After the White House gave initial approval and then settled the final details with senators, that became the version that was shepherded into law. The president next tried to strike a deal on a social spending and climate package with Sen. Joe Manchin, going as far as inviting the West Virginia lawmaker to his home in Wilmington, Delaware, until the conservative Democrat abruptly pulled the plug on the talks in a Fox News interview.

  • Taiwan flags flutter outside the presidential palace in Taipei, Taiwan August 8, 2022. 

    Air traffic returning to normal, says Taiwan govt

    Air traffic around Taiwan is gradually returning to normal after airspace surrounding the island reopened, Taiwan's Ministry of Transportation and Communications said on Monday, although China later announced fresh military drills in the area. China last week deployed scores of planes and fired live missiles near during military exercises sparked by U.S. House of Representatives Speaker Nancy Pelosi's visit to Taiwan.

SHARE
Story Saved
×
Saved Articles
Following
My Reads
Sign out
New Delhi 0C
Monday, August 08, 2022
Start 15 Days Free Trial Subscribe Now