Spatial distribution and growth of Trapezium liratum, an endangered species, in Lake Obuchi

Abstract

The spatial distribution, density, and growth of Trapezium liratum, an endangered species, in brackish Lake Obuchi were investigated. The density of T. liratum was high in areas where the water depth was 1∼1.5 m with a rocky reef substrate, abundant stones and shells of Crassostrea gigas, and a high density of seagrass (Zostera marina). The experiments using enclosures revealed that the increases in the shell length and weight of T. liratum occurred when the monthly average water temperature exceeded 15°C, whereas those increases subsided at temperatures < 15°C.