Reducing stress and rising releasing survival rate of black porgy (Acanthopagrus schlegeli) after transportation
Date Issued
2009
Date
2009
Author(s)
Lu, Jung-Chi
Abstract
Due to the fisheries resources decreasing in recent years, several coastal counties released hatchery-reared fry to enhance stocks in Taiwan. However, the fry physical state after transportation in releasing procedure will influence the release efficiency. Therefore, it is important to handle the salinities during transportation and calm times after transportation. This study included three experiments. Firstly, estimate the recovery time after handling stress by measuring opercular beat frequencies and behavior activity of black porgy (Acanthopagrus schlegeli), and estimate the recovery time after transportation stress by measuring cortisol. Secondly, three groups of fish were transported by car from National Taiwan University in Taipei to Mao Aw hatchery in Northeastern Taiwan. The treatments of salinities were 7.5‰, 14.9‰ and 29.8‰, and calm times were 0h, 1h and 2h, respectively. Then, each was moved to the tank and encountered the Malabar grouper (Epinephelus malabaricus) after ten minute. The aim of this experiment is to compare the antipredator responses including schooling, swimming to the bottom of the tank, and swimming after the Malabar grouper. iii he results are as follows: (1) time to recovery estimated by measuring opercular beat frequencies was 60 minute, and by behavior activity was 75 to 90 minute, and by cortisol was one day; (2) the survival rate of 29.8‰ group was lower than that of 15‰ and 7.5‰ after transportation, 1 week releasing (p<0.05); (3) the antipredator responses of 0h calm time group was lower than that of 1h and 2h(p<0.05). In this study, we found the time to recovery after transportation was 60 to 90 minute based on behavior, and one day based on physical, there were lower transportation and releasing survival rates of the black porgy fry after transportation with high salinity, and there were weaker antipredator responses without time to calm. It was suggested that low salinity during transportation and 60 to 90 minute calm time after transportation were necessary for the releasing program.
Subjects
Acanthopagrus
schlegeli
transportation
stress releasing
SDGs
File(s)![Thumbnail Image]()
Loading...
Name
ntu-98-R95b45021-1.pdf
Size
23.32 KB
Format
Adobe PDF
Checksum
(MD5):ea5943e323af9b53248e3d05266527d2