open access

https://hdl.handle.net/2115/35535

Development of male reproductive organs during sexual maturation in the Japanese common squid Todarodes pacificus

日本語

1991

日本水産学会

Bulletin of the Japanese Society of Scientific Fisheries

57(12)

2237-2241

Development of male reproductive organs during sexual maturation was studied for Japanese common squid caught from feeding and spawning grounds. The male maturity was divided into five stages based on the histological observation of the testis. The maturity was compared with testis somatic index (TSI: testis weight as a percentage of body weight) and accessory gland somatic index (AGSI: accessory gland weight as a percentage of body weight). Results showed that sperm have already been produced in the testis even when the testis is a relatively small size, and that the male maturational process consists of two phases. In the first phase, sperm are produced in the testis and in the next phase sperm are transferred into the accessory gland, stored there in the form of spermatophore until copulation with the female. In the maturation stage, sperm are still produced, which means that copulating behavior is repeated by same male during this final sexual stage. It is possible to express the male maturity condition by TSI and AGSI. These numerical values are TSI>0.5 and AGSI>0.1 in the maturing stage; TSI>2.0 and AGSI>l.0 in the mature stage.

学術雑誌論文

Version of Record

© 1991 The Japanese Society of Fisheries Science

0021-5392

1349-998X

AN00193422