A Chromosome Study of the Ayu, a Salmonoid Fish

Abstract

The present study was carried out to clarify the morphology and the number of chromosomes that the ayu represents. The material, Plecoglossus altivelis, was obtained from Lake Biwa, a lake in the main island of Japan. The air drying technique was used to obtain chromosome preparations of kidney tissues after injection of 0.5%. colchicine. The diploid number of chromosomes in the ayu amounted to 56, including 12 biarmed and 46 telo- or acrocentric chromosomes. The number of arms was 68. Four pairs of small dot like chromosomes were also observed.