Tokyo, Feb 2 (Kyodo) A Japanese research team has foundeggs of natural Japanese eels in the Pacific Ocean off theMariana Islands for the first time, providing answersto longtime mysteries of where and when the fish spawn, itsaid in the British science magazine Nature Communicationsissued on Tuesday.
The team led by Katsumi Tsukamoto, a researcher at theUniversity of Tokyo''s Atmosphere and Oceanic ResearchInstitute, said it collected 31 eel eggs near the West MarianaRidge shortly before the new moon in May 2009.Most eels, popularly eaten in Japan, are currently raisedin farms using fry caught in the sea. But the team hopes thelatest discovery will help enable eel farming from eggs andprevent further declines in the eel population.
Using a net for plankton in filtering seawater, the teamfound eel eggs, estimated to have been fertilized about 30hours before, in a 10 kilometer-square area located south ofthe oceanic ridge.
The team also found newly hatched eel larvae concentratedat a depth of about 160 meters, leading them to believespawning takes place at a depth of around 200 meters and theeggs gradually rise to the level.
Fifteen adult Japanese eels and giant mottled eels inspawning condition were also caught in the same area, theysaid.
In the study that began in the 1970s, the team firstestimated the spawning area to be near seamounts and thespawning period to coincide with the new moon.
In 2005, they found larvae two days after hatching butwere unsuccessful in finding the actual eggs. (Kyodo)