Ayu grow a little 50 days after the beginning of spring (the first day of spring according to the lunar calendar), and begin to go up to fresh water from the mouth of a river, and grow up to about 9cm long in May.
鮎は立春後およそ50日を経れば、やや成長し海口から河川の淡水にのぼりはじめ、5月になれば3寸くらいに成長する。