Salinity Tolerance of Black Carp (Mylopharyngodon piceus) at The Fingerling Stage

Abstract

      To test the culturability in brackish water the experiment was carried out to evaluate the salinity tolerance of Black carp (Mylopharyngodonpiceus) at the fingerling stage. Fish at size of 45 ± 0,3 gram/individual were stocked in several 120L-buckets with stocking density of 15 fish/bucket. The experiment included in 2 trials: trial 1 was conducted to assess salinity tolerance without acclimation when putting Black carp fingerlings directly from fresh water into treatments with different salinity concentration of 0, 5, 10, 13, 15, 17, 20‰; trial 2 was designed similar to trial 1 but fish was acclimated in brackish water before putting into different salinity concentration treatments. The results showed that non-acclimation black carp have 100% survival rate at the salinity of 13‰, but 100% mortality after 102 hours at 15‰, 12 hours at 17‰ and 4 hours at 20‰. Similarly, in the trial 2 with acclimation condition, Black carp were alive 100% at the salinity 13‰ and died quickly at higher salinity levels. Comparison of trial 1 and trial 2 in both condition revealed that Black carp could adapt and grow well in the arrange of salinity from 0-13‰, but quickly died without acclimation at 15‰ and showed no significant differences at 17 or 20‰. The growth rate of Black carp fingerlings in salinity 0‰ was highest with7,9a ± 0,61(gram/fish/week) and in lowest in 13‰ salinity (5,6c ± 1,12 (gram/fish/week). Histological observation indicated that there was no change in shape and structure of gills and kidney at the salinity of 0, 5, 10, 13‰, but at the 15‰ fish gills were dehydrated and shrinked and the kidney was clustered.