Effects of salinity on Streptococcus infection of nile tilapia, Oreochromis niloticus
Journal
Journal of Applied Aquaculture
Journal Volume
6
Journal Issue
1
Pages
39-45
Date Issued
1996
Author(s)
Abstract
The effect of 0, 15, and 30 parts per thousand (ppt) salinities on three isolates of Streptococcus infection of "injured" Nile tilapia, Oreochromis niloticus, at 25 and 30°C were determined. No deaths occurred in fish in any environmental regimen unless they were exposed to Streptococcus. However, increased susceptibility to to Streptococcus was associated with elevated salinities at 25 and 30°C. Mortalities were not significantly (P > 0.05) higher in 15 ppt salinity than 0 ppt at 25°C, but at this temperature, mortalities of Streptococcus infected tilapia were significantly (P < 0.05) higher at 30 ppt than at 0 or 15 ppt salinities. At 30°C, mortalities of fish infected with two Streptococcus isolates were significantly (P < 0.05) higher at 15 ppt than an 0 ppt salinities. All groups of fish at 30°C in 0 ppt or 15 ppt salinities had significantly higher mortalities than the corresponding groups held at 25°C. Mean day-to-death generally decreased as temperature was increased from 25 to 30°C, but a greater difference was noted in most instances as salinity increased from 0 ppt to 15 ppt and 30 ppt. © 1996 Taylor & Francis Group, LLC.
SDGs
Type
journal article