ACCUMULATIOIVAND ELIMINATION OF PATHOGENIC BACTE'RIA BY TILAPIA FISH SPECIES.

ACCUMULATIOIVAND ELIMINATION OF PATHOGENIC

BACTE’RIA BY TILAPIA FISH SPECIES.

By
M.A. EL-SHENAWY, AND M.E. EL-SAMRA
National Institute of Oceanography and Fisheries, Suez and Aqaba Gulfs

Branch, Ataka, Suez, Egypt.

Key Words: Pathogenic bacteria, Fecal coliforms, Tilapia Fish Sp.

ABSTRACT
LaboratolY experinlents were done to investigate the rate of bacterial ,­
contanlination in Tilapia sp. This include total aerobic bacteria, total
col(forms andfecal coliforms. The jish was exposed to sewage waterjor 12
hours (contanlination period) and subsequent elinlination period in clean
waterfor the next 180 hours.
During the contanlination period, the numbers oftotal aerobic bacteria,
total col(fornls andfecal coli/orms in skin, gills and alimentary canal were
increased by 4.5, ..J1.6 and 4.1, and 105, 65 and 38, alld 20,42 alld 13 folds
over the initial numbers re,f;pectively.
After 132 hours ofelinlination period, bacterial cOllnts approximated the
initialnunlbers or less, except in gills where slightly higher numbers oftotal
coliforms were recorded No colifornl bacteria was detected infish muscles
during the accumulation and elimination periods.