Lemon Sharks Go Back Home to Give Birth, Find Researchers

SeaDiscovery.com
Monday, December 09, 2013
Lemon Shark: Photo Wiki CCL

In the marine world, natal philopatry (animals returning to their own birthplace to give birth to their young) has been documented in salmon, seals, and some sea turtles; but for the first time, the phenomenon has been recognized in lemon sharks, researchers at the Field Museum in Chicago discover.

What is a lemon shark?
“A lemon shark is a large coastal shark, mainly found in the western Atlantic,” says Kevin Feldheim, A. Watson Armour III Manager of the Pritzker Laboratory for Molecular Systematics and Evolution at The Field Museum, who did his dissertation on these sharks.  “They are about as sharkey-looking as they come, and are called lemon sharks because their bellies are light, almost yellow, like a lemon.”

For the past 20 years, Field Museum scientists and collaborators in the Bahamas have been tracking female lemon sharks from birth through sexual maturity, and have found that some females do return to their birthplace to give birth to their pups.

Research
Each year, young sharks 0-2 years old, are collected and tagged using the same microchips that pet owners can place in their dogs.  The microchip acts as a collar of sorts, and can provide information about the identity and age of the animal.  In addition, a piece of the shark’s fin is taken for genetic analysis at the Pritzker Laboratory, right here at The Field Museum.

Using DNA from the fin, Field Museum scientists were able to create a database and determine family relationships, based on the similarity of the DNA sequences.

“We use a program that will create a parental pedigree for us, using the DNA of the newborn sharks,” said Feldheim.  “We can tell if a baby shark belongs to a female whose DNA is already in our database, and these relationships are confirmed by catching the animals.  For example, in 2008, we caught and tagged a pregnant female, and four years later, we caught several of her babies.”

“What is novel about our findings is that [lemon shark] nursery areas play a much stronger role in supporting local populations.  So, conservation of local populations needs to occur at a much finer scale (in addition to the needed larger regional scale)," concludes Feldheim.

Source: The Field Museum
 


People & Company News

Rickmers Holding, E.R. Capital Drop Merger Plan

Rickmers Holding AG and E.R. Capital Holding have jointly decided not to pursue the merger of their ship management activities.   For many years the companies

MN100: Conrad Shipyard

The Company: Conrad Shipyard was established in 1948 and is headquartered in Morgan City, Louisiana. The company designs, builds and overhauls tugboats, ferries,

Why Maritime Museums Matter

With today’s focus on digital technology, mobile apps, enhanced reality and the overall digital landscape, the maritime industry often gets overshadowed, leaving some to ask,

Environmental

C-Job Designs Flettner Freighter for Switijnk

The Dutch shipping company family Switijnk has contracted C-Job Naval Architects to develop a Rotor Sail-equipped design to meet their specific loading and sailing profile.

Vitol's Malaysia Terminal Suspends Ops after Spill

VTTI, the storage unit of world's largest oil trader Vitol, has suspended operations at its terminal in southern Malaysia following an oil spill, two industry sources said on Friday.

Danish Maritime Authority Supports Maritime Cultural Days

The Danish Maritime Authority's buoy tender ’POUL LØWENØRN’ will be alongside in Korsør in connection with the Maritime Cultural Days. The vessel will be open to visitors throughout Saturday,

Marine Science

Global Climate Change Threatens Papahānaumokuākea Marine

Despite its remote location in the Northwestern Hawaiian Islands, Papahānaumokuākea Marine National Monument faces a looming threat of global climate change that

SC Fisheries Research Vessel Repowered

A fisheries research vessel operated by the South Carolina Department of Natural Resources (SCDNR), was recently repowered with new eco-friendly fuel-efficient engines from Volvo Penta.

Fighting Barnacle Buildup with Biology

New research solves a mystery behind the gunk that sticks to the bottoms of ships.   The coating of barnacles and other growth along the bottoms of vessels is more than just an eyesore.

Ocean Observation

South Asia Meet on Oil, Chemical Spill Contingency Plan

A meeting to update South Asia’s regional plan for oil and chemical pollution preparedness and response is underway in Male, Maldives (22-25 August), informs  International

Global Climate Change Threatens Papahānaumokuākea Marine

Despite its remote location in the Northwestern Hawaiian Islands, Papahānaumokuākea Marine National Monument faces a looming threat of global climate change that

Indonesia to Change Name of South China Sea to Natuna Sea

President of Indonesia Joko Widodo, commonly known as Jokowi,  has vowed to transform Indonesia, which includes 17,000 islands into a ‘maritime power’, and also

 
 
Maritime Careers / Shipboard Positions Maritime Standards Naval Architecture Pipelines Pod Propulsion Port Authority Salvage Ship Electronics Shipbuilding / Vessel Construction Winch
rss | archive | history | articles | privacy | contributors | top maritime news | about us | copyright | maritime magazines
maritime security news | shipbuilding news | maritime industry | shipping news | maritime reporting | workboats news | ship design | maritime business

Time taken: 0.0880 sec (11 req/sec)