Nippon Suisan Gakkaishi 65 (3), 457-463 (1999)

Plasma Cortisol Level for Stress Measurment of Japanese Whiting Sillago japonica Captured by Sweeping Trammel Net

Atsuhiro Tsunoda,* Ari Purbayanto,*
Seiji Akiyama,* and Takafumi Arimoto*

To investigate the stress response of Japanese whiting Sillago japonica associated with the capture process of sweeping trammel net, plasma cortisol levels of the fish were measured as a stress index. The result revealed that the plasma cortisol levels increased from just after capture to 24 hours, then tended to decrease in 72 hours by keeping them in a tank. In the gilled capture, changes in cortisol level were relatively similar, while for the pocketed capture, it decreased after 24 hours. Changes in plasma cortisol of mesh-cut released samples for gilled capture were relatively similar to the usual gilled capture. Hook and line stress, however, did not show any fluctuation compared to the sweeping trammel net capture. Tight contact with the mesh twine for the gilled fish during the capture process was considered to cause the higher stress of fish.


  [BACK]  [TOP]