クロダイ成魚による養殖ワカメの食痕の特徴と採餌󠄀行動

Characteristics of bite scars observed in the cultured wakame Undaria pinnatifida by the Japanese black seabream Acanthopagrus schlegelii and feeding behavior

Creators Noda Mikio

Creators Murase Noboru

Recently overbrowsing by fish in cultivation of the wakame Undaria pinnatifida has become problematic and in particular the Japanese black seabream Acanthopagrus schlegelii. We examined characteristics of bite scars left on thalli of the cultured U.pinnatifida by feeding of the Japanese black seabream A. schlegelii in a tank experiment. The species showed active feeding behavor of the cultured U. pinnatifida and fed on stems as well as blades. Blades and stems were sharply torn by biting and shaking its head and thus most of bite marks left on blades were straight cut surfaces. However, cross sections in consumed stems were not only straight but also split in a number of strands. The shape of bite marks on the thalli was thought to be usefull for identifying the fish species that caused feeding damage of the cultured U. pinnatifida.

[ISSN]0370-9361