Impact of heavy fuel oil on the abundance of bacteria in the digestive tract and growth of rainbouw trout Oncorhynchus mykiss larvae

摘要

In this study the effect of heavy fuel oil on intestinal bacterial populations of rainbow trout (Oncorhynchus mykiss) larvae was investigated. Heavy fuel oil addition into the environment of fish larvae induced changes in total heterotrophic and proteolytic bacterial counts in the intestinal tract of 18 and 25 days old fish. Significant numbers of indigenous hydrocarbon-degrading bacteria were observed in fish larvae intestinal tract before contamination with heavy fuel oil. Introduction of heavy fuel oil into the environment of rainbow trout larvae resulted in increase of abundance of hydrocarbon-degrading bacteria in their intestinal tract. During the exposure to heavy fuel oil the growth of fish larvae was poor and the toxic effect was determined on both total body weight and total body length.