Occurrence of the Abnormally Colored Sea Bass Meat, Associated with Massive Outbreak of Oyogipinno Crab Tritodynamia horvathi

Abstract

Many of the sea bass Lateolabrax japonicus whose meat was abnormally colored yellow, orange or red, were caught in Tokyo Bay in July and August, 1979.
Most of the colored substance was extracted from those abnormal muscles with acetone or chloroform-methanol (2:1). The extracts showed absorption maxima at around 440, 460, and 485 nm in benzene, and 430, 455, and 475 nm in petroleum ether, indicating the presence of several carotenoids. In the gut contents of a sea bass specimen were recognized the debris of small crabs “ oyogipinno ” Tritodynamia horvathi. In this connection, a massive outbreak of oyogipinno was observed in Tokyo Bay during the summer of 1979. The chloroform-methanol or acetone extracts from the muscle or gut contents of the sea bass, and from the whole body of the crab, coincided with each other in spectral characteristics.
It was concluded that the colored meat of sea bass was caused by an unusual accumulation of carotenoid pigments, which may have resulted from the ingestion of a large amount of oyogipinno crab.