2012年6月に瀬戸内海西部の山口湾で,ハゼ科の準絶滅危惧種であるショウキハゼTridentiger barbatus 1 標本が採集された。全長110.1mm,体長89.4mm,雌の成魚で,卵巣は発達し,GSI は1.59%であった。細胞・組織学的検討より,最も発達した正常な卵母細胞は第二次卵黄球期で,新しい排卵後濾胞細胞を多数認めたことより,産卵期における複数回の産卵が示唆された。今回,標本に基づき山口湾における生息と産卵を初記載した。

A specimen of Shokihaze goby, Tridentiger barbatus, was collected from Yamaguchi Bay, western Seto Inland Sea, Japan in June 2012. This species has been evaluated as a near threatened species in Japan. This specimen was an adult female of 110.1mm TL and 89.4mm SL. The gonadosomatic index was 1.59%. Histologically the most developed stage of normal oocytes was the secondary yolk globule stage. The specimen had a lot of new postovulatory follicles in the ovarian lamella and a few ovulated ripe oocytes remained in the ovarian cavity. Therefore, these results indicate that spawning has occurred and this species is a multiple spawner. This is the first report of the occurrence and spawning of T. barbatus, based on a specimens from Yamaguchi Bay.