Last October, officials with the Toronto and Region Conservation Authority discovered rudd, an invasive fish, in its studies at Lake Wilcox in the northern end of the town.

Ministry of Natural Resources officials fear the species, which first showed up in Lake Ontario, could cross breed with the indigeneous golden shiners.

Additionally, this invasive fish could disrupt spawning and nursery habitats of other native species that inhabit Lake Wilcox, including northern pike, muskellunge and yellow perch and create an ecological imbalance in the lake.

Fishermen dumping their bait buckets into the lakemay have caused the species to be introduced into the lake.

Officials believe it's the first time the rudd has been found in an inland lake in the province.

Prior to its discovery in Lake Wilcox, the rudd was known to occur only in isolated locations along the St. Lawrence River and lower Great Lakes.

Mark Heaton, Aurora District ministry biologist, hopes it was an isolated case.

The ministry will do a further assessment at Lake Wilcox in the spring, he said.

An investigation into whether or not more of the fish have invaded the lake will be conducted in the spring.

The rudd is a large, deep bodied minnow that can grow to a length of 35 centimetres and a weight of 1.8 kilograms.

It is similar in appearance to the native golden shiner, but rudd has blood-red fins (a golden shiner's are yellow) and a fully scaled belly.

The public can help stop the spread of this invader by taking the following precautions:

· Learn to identify invasive and non-bait species at invading species.com

· Check bait buckets carefully for invasive or non-bait species before going out on any lake or river.

· Prevent the introduction of invasive fish species or other organisms invisible to the naked eye by never releasing baitfish or dumping the contents of bait buckets into a lake or river or on the ice of a lake.

Anyone finding minnows suspected of being an invasive species should freeze them and call the invading species hotline at 1-800-563-7711.