It has been a mystery until now what the oysters, which are actively cultivated in the sea, feed on immediately after hatching from eggs, but fisheries research has shown that they are eating a very small new species of plankton. The research group of the Education Organization has clarified it, and it is expected to be applied to aquaculture technology.
Pacific oysters grow on phytoplankton when they grow up, but it has never been confirmed what they are eating during the larval period when they hatch from eggs and float in the sea, and it has been a mystery until now.
A research group led by Masami Hamaguchi of the Fisheries Research and Education Agency analyzed the contents of the digestive tract of oyster larvae taken in Hiroshima Bay using the latest DNA analysis technology.
As a result, two new species of plankton called "Keiso" were detected.
Both are cylindrical with a diameter of about 5 micrometers, and are said to be a special type that is extremely small, about one tenth of the general "Keisou".
When this new species of "Keiso" was added to the oyster larvae, it was confirmed that they were eating.
Since this new species of "Keisou" is extremely small, it has not been sufficiently studied until now because it was thought to be a large plankton mortal fragment, but when examined again, it is a sea area where oyster larvae are abundant. It means that it was found that it inhabits a lot in Japan.
Mr. Masami Hamaguchi of the Fisheries Research and Education Agency said, "I was surprised because I didn't even know that it was a living thing. I can expect it to be applied to technology for collecting oyster larvae."