Salinity Tolerance and Survival of Freshwater Carp, Labeo rohita Ham. (rohu) in Inland Saline Water

The present study was conducted to assess salinity tolerance and survival of freshwater carp, Labeo rohita Ham. (rohu) in inland saline water. Fingerlings of rohu (11–12 cm) were exposed to 0, 2, 4, 6, 8 and 10 ppt (o/oo) salinity water for 10 days. Fish was acclimatized to different salinities by increasing the salinity gradually @ 1 ppt hr−1. During the tolerance test, no mortality of fish was recorded up to 10 ppt salinity level and fish behaviour, in terms of swimming movement and appetite (feed intake), remained unaltered up to 4 ppt salinity. However, at 6 ppt salinity fish became less active after 7 days, while at 8 and 10 ppt salinities fish became less active after 6 days and sluggish after 8 days of exposure. Fish also exhibited low appetite in 8 and 10 ppt salinities after 8 days of exposure. The present study suggests that L. rohita, can tolerate salinity up to 10 ppt in inland saline water, but it is expected to perform well in salinities ≤6 ppt.