Abstract
The writer observed on the gonad and the number of eggs of Spirinchus lanceolatus from Mukawa coast of Iburi Province, Hokkaido in 1957.
The form of left and right gonads is asymmetrical as well as that of Hypomesus olidus and H. japonicus.
The length of gonads to the body length are 43.0% in left and 32.2% right gonads in ovary, while the testes are 24.6% in left and 17.5% in right sides. The ratio of length of testes to body length is smaller than that of ovary-length.
The weight of gonads to the body-weight are 19.5% in ovary and 1.05% in testis. Therefore, testes-weight was about 1/20 of the ovary-weight.
The length of gonad, its weight and number of eggs are shown in proportion to the body length.
