They are large, aggressive fish. Commonly found in lakes, rivers, streams and ponds. They tend to live in the clay, silt and gravel bottoms and hide under debris. They have rapidly spread. They are found throughout South-central and southeastern Ontario.
Feeding Habits
They are 'opportunistic' feeders, eating anything available to them. They eat large quantities of aquatic vegetation. They feed on aquatic plants, snails, clams, leeches, aquatic insects, crustaceans, small fish and fish eggs.
Life Cycle
Rusty crayfish tend to mate in early spring, early fall or late summer. Once eggs are fertilized, they attach to the females tail section. The eggs hatch in 3-6 weeks. The female is able to lay 80-575 eggs. After they're hatched, they still 'cling' to the tail section of their mother until they are bigger in size. They do this for protection. Their maximum length is 4 inches. A typical Rusty Crayfish lives for 3-4 years.
Rusty Crayfish eating
Limiting Factors
Before this was banned in 1983, Rusty Crayfish were used as live bait. They are also captured and brought home as dinner in some cases, because they are easy to catch and they taste good! Other animals like to eat crayfish too, whenever they happen to catch one. Some include mink, turtles, herons and cranes. Crayfish are considered a delicacy in some parts of the world. 100 million pounds of crayfish are harvested annually in the US, mostly from Louisiana.
They were likely introduced because they were used as live bait by 'anglers'. Females also carry fertilized eggs so it is much easier for them to spread. When they were used as live bait, some would get free and go into water that was not yet invaded by the crayfish. The females eggs would hatch and the cycle would continue to happen until they invaded the water.
Effects of the Rusty Crayfish
They eat much of the plants found in the water, and destroy the plant bed abundance. They also take the
place of the native species by taking much of their resources, space, and out populating them. They throw off the ecosystem because they weren't meant to be there and they eat things that native species eat, leaving the native species with less food. The rusty crayfish is thriving because it has no natural predators and since they re produce so quickly, they are always rebounding and increasing. They are able to eat a lot of different things because they are 'opportunistic feeders', and have a wide variety of choices. How to control the species
There are chemicals out there that will kill the crayfish, but none are specifically for crayfish control. The known chemicals that kill the crayfish, don't only kill the Rusty Crayfish, but would put other crayfish at risk as well. Since there is a large population of the rusty crayfish, harvest for human consumption would be a good use for the species, but would only reduce the adult population. Once the species is introduced to an ecosystem, it is almost impossible to eliminate them. Therefore, the best way to control them is to prevent future spread of the Rusty Crayfish.
What lessons have we learned?
In our opinion, you don't learn much from the Rusty crayfish, only that you have to be careful when dealing with invasive species because if they get loose, they can reproduce quickly and invade more areas.
What Can We Do?
We should learn to identify the Rusty Crayfish. We should not in any areas besides the Ohio River Drainage. Unused crayfish bait should be thrown away and never released into the water. Don't use crayfish as bait in general. Do not sell rusty crayfish.
B3.5 Identify various factors related to human activity that have impacted on ecosystems (the introduction of invasive species) and explain how these factors affect the equilibrium in an ecosystem.
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What is a Rusty Crayfish?
They are large, aggressive fish. Commonly found in lakes, rivers, streams and ponds. They tend to live in the clay, silt and gravel bottoms and hide under debris. They have rapidly spread. They are found throughout South-central and southeastern Ontario.Feeding Habits
They are 'opportunistic' feeders, eating anything available to them. They eat large quantities of aquatic vegetation. They feed on aquatic plants, snails, clams, leeches, aquatic insects, crustaceans, small fish and fish eggs.Life Cycle
Rusty crayfish tend to mate in early spring, early fall or late summer. Once eggs are fertilized, they attach to the females tail section. The eggs hatch in 3-6 weeks. The female is able to lay 80-575 eggs. After they're hatched, they still 'cling' to the tail section of their mother until they are bigger in size. They do this for protection. Their maximum length is 4 inches. A typical Rusty Crayfish lives for 3-4 years.Limiting Factors
Before this was banned in 1983, Rusty Crayfish were used as live bait. They are also captured and brought home as dinner in some cases, because they are easy to catch and they taste good! Other animals like to eat crayfish too, whenever they happen to catch one. Some include mink, turtles, herons and cranes. Crayfish are considered a delicacy in some parts of the world. 100 million pounds of crayfish are harvested annually in the US, mostly from Louisiana.Where did the Rusty Crayfish come from?
They are normally distributed from Illinois, Ohio and Indiana.How were they introduced into our ecosystem?
They were likely introduced because they were used as live bait by 'anglers'. Females also carry fertilized eggs so it is much easier for them to spread. When they were used as live bait, some would get free and go into water that was not yet invaded by the crayfish. The females eggs would hatch and the cycle would continue to happen until they invaded the water.Effects of the Rusty Crayfish
They eat much of the plants found in the water, and destroy the plant bed abundance. They also take theplace of the native species by taking much of their resources, space, and out populating them. They throw off the ecosystem because they weren't meant to be there and they eat things that native species eat, leaving the native species with less food. The rusty crayfish is thriving because it has no natural predators and since they re produce so quickly, they are always rebounding and increasing. They are able to eat a lot of different things because they are 'opportunistic feeders', and have a wide variety of choices.
How to control the species
There are chemicals out there that will kill the crayfish, but none are specifically for crayfish control. The known chemicals that kill the crayfish, don't only kill the Rusty Crayfish, but would put other crayfish at risk as well. Since there is a large population of the rusty crayfish, harvest for human consumption would be a good use for the species, but would only reduce the adult population. Once the species is introduced to an ecosystem, it is almost impossible to eliminate them. Therefore, the best way to control them is to prevent future spread of the Rusty Crayfish.
What lessons have we learned?
In our opinion, you don't learn much from the Rusty crayfish, only that you have to be careful when dealing with invasive species because if they get loose, they can reproduce quickly and invade more areas.What Can We Do?
We should learn to identify the Rusty Crayfish. We should not in any areas besides the Ohio River Drainage. Unused crayfish bait should be thrown away and never released into the water. Don't use crayfish as bait in general. Do not sell rusty crayfish.B3.5 Identify various factors related to human activity that have impacted on ecosystems (the introduction of invasive species) and explain how these factors affect the equilibrium in an ecosystem.
Answers to questions on topic.
Choses relevant and interesting pictures, videos, and links.
Spelling, grammar, neatness and organization.
Apply functions and capabilities of Wiki to page.