Language selection


Using cinnamaldehyde as an inhibitor of the common fungus, Saprolegnia parasitica, infecting brook trout and rainbow trout eggs and fry



The common fungus Saprolegnia parasitica is a "water mold" that takes the form of cottony tufts composed of branched filaments (mycelia). Saprolegnia infects dead fish eggs and then spreads to healthy eggs. It also infects the yolk sac and digestive tract of fry that are just starting to feed, as well as the skin, gills and fins of fish. The fungus attacks the epidermis and dermis, eroding the tissue as it develops. Saprolegniosis creates a major physiological problem for fish (e.g. destruction of the osmoregulatory system) in addition to providing an entry point for microbial infections. If left untreated, saprolegniosis quickly results in mortality rates of as high as 50% in salmonids and other fish species. In 1936, the aquaculture industry around the world began using malachite green as a biocide. Known to be highly effective for its antifungal, antimicrobial and antiparasitic properties and inexpensive to use, malachite green has today become a highly controversial substance at the international level. Preliminary in vitro studies recently carried out have shown the effectiveness of cinnamaldehyde, a natural substance, as an antifungal agent to combat S. parasitica. The primary objective of the project is to test the effectiveness of cinnamaldehyde as an antifungal agent in the eggs and fry of brook trout (Salvelinus fontinalis) and rainbow trout (Oncorhyncus mykiss).

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)


2007 - 2010


Atlantic: Gulf of St. Lawrence, St. Lawrence Estuary

Principal Investigator(s)

Grant Vandenberg

Date modified: