Salinity Tolerance of Freshwater Shubunkin Gold Fish, Carassius auratus (Linn.): Suitability for Rearing in Inland Saline Water Bhatt Deepa, Kaur Vaneet Inder*, Ansal Meera D., Kumar Pavan1 Department of Aquaculture, College of Fisheries 1Department of Livestock Products Technology, COVS, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana-141 004, India *E-mail: vinnygulati@gmail.com
Online published on 30 August, 2019. Abstract Short term salinity tolerance test (10 days) was conducted to assess the stress responses in terms of fish survival, behaviour and colouration of freshwater shubunkin gold fish, Carassius auratus (L.) in different salinity levels (2 to 10 ppt). Inland saline water (15 ppt) collected from district Fazilka (Punjab) was used for preparation of different treatment salinities after dilution with freshwater (0 ppt). After proper conditioning in indoor conditions, fish were acclimatized (gradual increase in salinity @ 1 ppt at 1-hr interval) and distributed @ 10/aquaria (50 liter capacity). There was significant increase in pH and NH3-N, however, these remained in tolerance range for freshwater fish culture. The rest of the parameters i.e. EC, TA, TH and ionic composition (Na+, K+, Ca+2, Mg+2, Cl− and SO42-) of water increased significantly in accordance with the composition of source inland saline water. At the termination of salinity tolerance test, percent fish survival did not vary significantly, however, in 0 and 2 ppt, it was 100%, which decreased to 96.66% in 4, 6 and 8 ppt and 93.33% in 10 ppt. Fish behaviour w.r.t. swimming activity and feeding responses showed gradual departure from normal behaviour. Deviation from normal skin colouration was insignificant in terms of L a*b* values and colour indices (chroma and hue) during short duration of 10 days exposure to increasing salinity conditions. Overall results are indicative of stimulation of adaptive mechanism in freshwater fish during shorter duration of salinity exposure. Top Keywords Salinity stress, Gold fish, Inland saline water, Colouration, Fish behaviour. Top |