At the 2024nd Annual Meeting of the Japanese Society of Aquaculture, held at the Okinawa Times Building in Naha from November 11th to 29th, 30, our university's graduate student, Kaori Imai, won the Outstanding Presentation Award.

【Winner】
Kaori Imai (1st year master's student, Marine Life and Resource Science, Graduate School of Marine Science and Technology)

[Title of award-winning research]
Age structure and sex change rate of the breeding population of Japanese anchovy in Tokyo Bay 

[Details of award-winning research]
The sex determination of the silver anchovy is highly sensitive to the environment, and depending on the water temperature and photoperiod conditions experienced during the larval and juvenile stages, the sex may change to the opposite sex from that determined by the sex chromosomes. With global warming progressing, if the sex ratio of wild breeding populations is significantly biased due to environmental factors, the survival of the species itself may be in jeopardy. In this study, we conducted a survey of the actual situation of this species in Tokyo Bay and revealed that approximately 9% of the breeding population, both males and females, are 1 to 10 years old, and that approximately 30% of each year class are XY female sex reversals and approximately XNUMX% are XX male sex reversals. In addition, since there is a certain number of older fish that have changed sex in the breeding population, we showed that sex reversals may affect the genotypic/phenotypic sex composition of the population in the following years.

　　　　　　　　　　　　　　　　　　　　　　　　　Imai

<Related links>
Japan Fisheries Breeding Society