Can a Frog Kill Fishes? The Reasons Why


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The health of fishes can be affected by many things in the water of a fish tank especially toxins. Frogs and other invasive species can introduce deadly biological chemicals which can kill your entire fish population within hours.

Fishes can be killed by frogs when they share the same space. Frogs, mainly toads, secrete a toxic chemical called bufotoxin when stressed which is a poisonous substance meant to make the toad unpalatable to potential predators. This chemical is dangerous to many small animals including fishes and can kill an entire fish population.

American toads and many other frog species require water to breed, get hydration and cool down after a hot day. They are often found in patches of dense vegetation and hide most of the day after which they emerge at night. 

This is when they are most active since their food supply, mainly insects, are also active during this time. These insects include bugs, spiders, worms, slugs, larvae and even small fish. For this reason, they are a vital part of the environment whereby they keep other pesky insects at bay.

What Attracts Frogs to fish Tanks?

Frogs can hear and sense water trickling from a distance and head straight towards it. Water provides the breeding ground for frogs. Here’s the perfect place to find a mate since other frogs will be attracted to the same thing.

Frogs can leap or crawl and climb their way into fish tanks and ponds if the environment allows. This is a win for the frog if they succeed to get in but it doesn’t work out too well for the aquatic animals living within the fish tank or pond.

Once inside the fish tank or pond, the frog can have a field day with smaller fishes and will eat any fish once they are small enough to fit into its mouth. Smaller fishes may include goldfish, koi, tetras and guppies.  Even if the frog is smaller than the fishes it is very unlikely that the fishes may attempt to eat it. 

How can a Frog Kill All the Fishes in a Tank?

If getting into the fish tank is a task for the frog then getting out will be just as hard if not impossible. 

The frog may hang around for a bit and then try to escape. Now, this may cause an even bigger problem. In the case where the frog realizes that it cannot escape, it will become stressed quickly.

When frogs, mainly toads, are stressed they release toxins called bufotoxin. Named after the species. The toxin is released onto the back of the toad as a stress reaction which enters the water stream.

These Bufotoxins are toxic to fishes and can kill the entire fish population within hours of release. The fishes will not stand a chance with a stressed frog within the same environment.

How To Prevent Frogs from Entering My Fish Tank?

An easy way to prevent frogs from entering into your fish tank is to have proper barricades which physically prevents frogs from leaping into the water.

The barricades just have to be high enough to prevent them from gaining access to the fish tank or pond. This is the best method of prevention since it doesn’t harm the frogs or the fishes.

Another method of control is to spray repellents around the pond or fish tank. Repellants such as vinegar and salt water can repel frogs effectively without killing them. These are organic methods of control which act as irritants to the frogs.

The vinegar and salt can be sprayed around the pond and yard to deter frogs from venturing too close to the water and fishes.This should be done on a routine basis to ensure that the frogs don’t come close to the fishes.

Chemicals can also be used to get rid of frogs but is not recommended since frogs play an important role in the ecosystem.

What can wrong in aquaponics

This is a picture of the fishes in my Aquaponic system which was taken a year ago. I had 30 koi and a number of tropical fishes and guppies which where all growing very healthy. I checked and fed them routinely until one morning I discovered that all the fishes where dead.

It was a frog, A FROG! He decided to leap into my biofilter. He couldn’t escape so he released stress chemicals from the pores of his skin into the water.

The chemical was poisonous to the fishes in my tank and they all died. The entire system had to be shut down, cleaned and restarted. The cost of this incident was in the thousands and could have been prevented with a simple barrier, salt water or vinegar.

After much research,
My findings are – A frog can kill fishes in aquaponics or any other fish system.

I complied this article so I can shed a little light on how frogs can affect fishes especially those in an aquaponic system.

JayLea

JayLea has a passion for plants and has been gardening since 2015. He has valuable knowledge about gardening and houseplant care and can answer everyday practical questions that every plant owner has.

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