Crayfish are freshwater creatures that may be found in streams, ponds, and marshes. they are little crustaceans that resemble lobsters in appearance. People throughout the world believe crayfish to be a tasty dish and many homes consider blue crayfish to be treasured aquarium pets.
Crayfish typically live in freshwater streams and rivers. This environment normally consists of stone, mud, vegetation, and a fast-moving current.
Notably, crayfish are excellent burrowers, which is why they love brackish water.
Crayfish normally eat decaying animal matter and vegetation. They will also eat frogs that swim or jump by. In the wild, this is not so easy as the frogs can easily swim away from the crayfish, but in a fish tank, this is not always the case. In a tank, particularly a small tank, the crayfish have a higher success rate in killing live frogs and tadpoles compared to what it would in their natural environment.
The common crayfish diet resembles that of their crab cousins a lot. Crayfish consume almost anything they come to find in the wild including seaweed, algae, fish, snails, and even each other! It does not matter to Crayfish whether their food is alive or dead – although they prefer the latter!
They will eat fish, shrimps, and frogs, as well as plankton, algae, and even insects.
Blue crayfish also consume decomposing plant waste that enters their water supply, such as grass, weeds, and tree leaves.
You can see from this that Crayfish will happily eat frogs if they are available in their environment.
Just remember: It is not just a one-way problem. Certain frogs have eaten smaller crayfish as well, which makes them less than ideal tank mates.
It is also important for you to know that crayfish will eat different thing depending on their species, habitat and what time of the year it is.
For example, the Northern Clearwater Crayfish eat much more animal matter than the Louisiana Crawfish but none of them eat tadpoles in winter (as they are not around!).
Do Crayfish Eat Tadpoles?
Crayfish are omnivores and eat both plants and animals. Generally, they have more success with slower-moving species, but if they come across tadpoles, they will certainly have a try at nipping them.
As crayfish develop from larva into fully grown crayfish, their food will change as they grow.
The survival of the tadpoles is also related to whether the crayfish are native varieties or one of the invasive varieties, which are more predatory. Tadpoles have a greater chance of survival with native crayfish than invasive ones.
Can I Keep Crayfish with Frogs in a Fish Tank or Garden Pond?
Crayfish are nocturnal, so it is not always possible to see how they hunt. At nighttime they crawl out of their hides and seek food. Normally, food will have sunk to the bottom, but the crayfish can swim a little and if something is slow-moving enough, the crayfish may catch it. They can also climb vegetation and rocks.
Frogs tend to be sedentary and would be an appealing target for a crayfish who could sneak up on it, if so minded. They are not ideal tank mates because of this, but if the tank is larger and deeper, the frogs may be ok, and any tadpoles will have more space to flee the crayfish.
Tadpoles that will grow into bullfrogs, once transitioned may well be a threat to the crayfish as large bullfrogs can sometimes attack smaller crayfish.
Bullfrogs are ambush predators that will devour worms, insects, crayfish, fish, other frogs, snakes, tiny turtles, small animals, and even birds.
They are the biggest frog in North America, weighing up to one pound and measuring up to eight inches in length.
Why you don’t want Crayfish in your pond
Crayfish populations can easily get out of hand in a pond and because of the wide range of their diet, they can strip a pond of other species. They eat the plants that oxygenate the pond and cause further damage. They can also erode the walls of the pond by tunneling.
Why you don’t want a bullfrog in your pond
Bullfrogs eat native wildlife like frogs, turtles, fish, crayfish, butterflies, and even birds. The population can easily explode and spread to neighboring water sources. In residential, they also produce a lot of disruptive noise at night.
In fact, bullfrogs are one of the animals that can easily eat crayfish – see all the fish or a full list of animals that eat crayfish in my other posts.
In some states, it is illegal to import and release live bullfrogs and crayfish as they are such a threat to native wildlife. Marbles crayfish are illegal in several states.
You can see from this article that crayfish are a threat to the natural environment and that great care should be taken with them.
It is also clear that while it is possible to home frogs and crayfish in the same tank, it can cause difficulties, especially in smaller tanks.
Crayfish eat frogs when they can, they eat tadpoles when they can, and tadpoles from Bullfrogs will also be a potential target.
Later on, when the tadpoles develop into bullfrogs, the adult bullfrogs may in turn eat the crayfish, so we see there is a two-way threat potential.