EFFECTS OF DIFFERENT SALINITY LEVELS ON PHYSIOLOGICAL AND HEMATOLOGICAL RESPONSE OF ROCK BREAM Oplegnathus fasciatus
Abstract: Rock bream
Oplegnathus fasciatus is one of economically important marine fish species in
East Asia. However, lack of information about the salinity tolerance of rock
bream related to its physiological response made this issue were needed to be
studied. The present study was conducted to determine the effects of different
salinity levels on physiological and hematological response of rock bream in
order to obtain its salinity tolerance. Twelve rock breams (total length: 26.9
± 0.6 cm, body weight: 477.3 ± 61.9 g) were used for experiments. Four
experimental groups with three replications were conducted to measure the
effects of salinity (5, 15, 25, and 35 practical salinity unit (psu)) on
physiological and hematological response of rock bream. Fish were stocked into
the chamber inside the closed recirculation system. At the end of each
experiment, blood samples were collected. The study revealed that lower
salinity exposure had tendency to decrease the physical and chemical properties
of blood in rock bream. The value of Na+, Cl-, Ca, Mg, and osmolality showed
tendency to decrease with lowering salinity, while cortisol and glucose showed
tendency to increase from 35 psu to low salinity environment, indicating the
enhancement of fish stress and resulted in fish mortality at 5 psu. The lowest
cortisol value was 76.3 ng/mL in 25 psu, and the highest value was 188.8 ng/mL
in 5 psu. Meanwhile, the lowest glucose value was 35.3 mg/dL and the highest
value was 166.7 mg/dL (P<0.05). Results indicate that rock bream could
tolerate lower salinity up to 15 psu.
Keywords: Oplegnathus
fasciatus; salinity; physiological response; hematology
Author: Vitas Atmadi Prakoso,
Jun Hyung Ryu, Byung Hwa Min, Rudhy Gustiano, Young Jin Chang
Journal Code: jpperikanangg160045