An eel egg. (Photo: aori.u-tokyo.ac.jp)
New findings on wild eels: researchers
Thursday, February 03, 2011, 02:10 (GMT + 9)
Researchers have unprecedentedly gathered wild eel eggs to unearth their spawning habits.
This will let the researchers uncover how and where the eels lay their eggs. Experts say these new findings could help open the door to novel eel farming techniques.
"Further research into the physical and biological surroundings in the area where the eggs were collected will contribute to eel production by telling us more about the environment and food information for farming eels," said Hideki Tanaka, a researcher at the Fisheries Research Agency and participant in the development, reports AFP.
The Japanese researchers collected 31 eggs near the West Mariana Ridge in the Pacific Ocean near Guam in May of 2009, according to British science magazine Nature Communications, in an issue published this week.
With the help of a net for plankton, the team took eggs that it estimates had been fertilised some 30 hours prior in a 10 sqkm-area south of the oceanic ridge, reports Kyodo News.
As well, the researchers found a group of newly hatched eel larvae at a depth of about 160 m, such that the team believes spawning occurs at a depth of approximately 200 m and the eggs later rise gradually.
"The eggs hatch only 1 1/2 days after being laid. We were lucky we were able to collect them," said professor Katsumi Tsukamoto of the university and leader of the team, reports Mainichi Japan.
Further, the researchers discovered that eels can spawn more than once during spawning season and that they reproduce during new moons because at this time the darkness protects them from predators.
The team consists of researchers from the University of Tokyo's Atmosphere and Ocean Research Institute and the Fisheries Research Agency.
Most of the eels consumed by humans are raised in farms using fry harvested in the wild. However, since the 1970s, eel fry stocks have taken a plunge due to overfishing and climate change.
In 2010, the Fisheries Research Agency was able to farm eels from eggs. Yet, the technology is not yet commercially viable, it said, because the number of eggs that hatch successfully remains low.
The researchers think the latest collection of eggs will help them reach groundbreaking results regarding the development of new eel farming technologies and facilitate conservation efforts.
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