Fish & Aquariums

Why There Are Worms In Freshwater Fish Tanks?

worms in freshwater fish tank
Written by Arlene S. Lane

Worms in the freshwater fish tank or any other fish tanks isn’t a very uncommon sight for fish tank setup. If your plan is to go for a fish tank for teens or kids and even for personal preference, doing research for it is always recommended. You will need to understand what is normal and what is abnormal in the fish tank. This can be challenging to distinguish and not only for the new fish tank owners but for the veteran ones as well. If you notice flatworms in a fish tank or any other types of worms in the fish tanks then your concern is natural. You might be wondering, where do they come from? what are they? are they dangerous to my fish and the ecosystem of the aquarium?

Depending on the aquarium setup be it a freshwater aquarium or saltwater aquarium setup, sometimes worms are inevitable. However, sometimes, aquarium pests can be an indication that there is something seriously wrong with your environment.

What exactly is Aquatic Worm?

Many aquarium setup owners are confused when they notice a protruding milky string from their fish’s anus. However, this is simply a typical digestive excretion and not at all a worm. And if you are wondering if can fish poop then yes, they do. Fish typically pass mucus while they are not eating or in between large, irregular meals. And the mucus coating the feces of other animals. These look like small white worms so it doesn’t possess any threat and are natural.

Real worms can be internal or exterior, parasitic or symbiotic. While symbiotic worms either assist their hosts or have no impact on their host or surroundings, tapeworms in goldfish solely behave for their own best interests and at the price of their hosts’ capabilities.

Different Types of Aquarium Worms

In any type of aquarium setup, there can be different types of aquarium pests. From basic to flatworms and tapeworms. Here is more to know about.

Trematodes – Flukes

Monogenean and digenean trematodes are the most primitive types of worms. Your fish’s gills and eyes can get extremely irritated by these worms. These parasites, sometimes known as “flukes,” are certain to cause issues for fish owners at least once in their careers. Since flukes are small, only a trained eye can notice them. You have probably seen them if you while examining the skin mucus of your fish using a microscope.

Flukes are the most common type of worms in reef tank and are mostly found in small numbers. However, they do not always possess the risk of any disease among fish. 

Flukes exist in almost all systems in very small numbers, but do not always induce clinical signs of disease. However, when the environment of the fish tank or pond is stressed or damaged, their small number will increase to a huge number. The signs of illness among fish because of these parasites include irritated skin that seems red, irritated behavior (including body rubbing against objects or tank walls, and bruising due to this behavior. These aquarium pests are easy to treat but you cannot remove them from the tank fully.

Cestodes – Tapeworms

It is far more difficult to identify internal cestode parasites like flatworms in fish tank or in fish. It might be very challenging to detect the active transit of cestode segments in the feces. The most typical indicator of sickness is a failure to thrive or acquire weight. Only a fresh fecal matter microscopic examination can provide a definitive diagnosis of cestode infection.

Treatments in the water will not work well with internal cestodes. A professional vet may prescript a food-based medicine which can be quite effective in this regard. 

Nematodes- Hookworms, Roundworms

The nematodes are one of the biggest groups of saltwater aquarium worms and include numerous parasitic, symbiotic, and pathogenic worms that may all have an impact on aquatic species. Bunostomum, Toxocara, genera Ancylostoma, and Uncinaria are among the found here. A huge number of aquatic invertebrates might belong to the nematode life span. As an aquarium owner, you will need to make sure to understand how these elements can affect its life cycle.

Larval migrans is a common disease famous by the nematodes migration from its larval cycle, aka hookworms. They can move to all body tissues and can cause significant disease among large species of animals and humans.

Crustaceans – Anchor Worms

Unlike other active saltwater aquarium worms, these worm types usually stay on the floor of the water bodies or in the aquarium. This is why they got the name “anchor worms”

This parasite is also a very common type of worms in reef tank and in the hobbyist community. What we see in the tank, those visible parts of worms are actually their reproductive organs. These crustaceans can penetrate deep into the muscle of the fish which can cause ulcers in different species of fish.

This fish type is very irritating to fish and can cause some severe health issues among fish. The good thing is, these worms in freshwater fish tanks can easily be diagnosed and treated.

Aquatic vets will add a combination of aquatic treatment and manual removal of the worms when fish will need treatment. This method will eliminate all adults engaged in reproduction and their eggs.

Annelids – Bristle Worms, Fireworms, Leeches

The majority of the common worms that people are familiar with are annelids. Leeches, earthworms, and tapeworms belong to this group. In saltwater ecosystems, bristle worms are the most widespread variety. It is very possible that they will make touch with the owner of a saltwater tank built by a non-experienced aquarium owner. 

If you want to know if these worms in freshwater fish tanks exist or not or if they are available in saltwater only? So, what you need to do is just give them touch and you will feel a stinger. Bristle worms often flair their bristle for their defense. It will inject into the human body a strong neurotoxin which can then cause severe pain. What is intriguing is that instead of brown antsjcousins, the fireworms hurt even more.

The best part is that fish will face any effect in any way by the more prevalent bristle worms. They primarily cause issues for caregivers. However, fireworms are famous to prey on insects. When it comes to treating them then you will need to understand that chemical treatment for these saltwater aquarium worms will also have a negative effect on the aquarium environment as well. To kill them easily, you should remove their feeding line. 

The majority of bristle worm infestations result from overeating. Worms hiding in the substrate use the extra fish food that settles at the bottom of the tank as their primary food source. The greatest method of controlling bristle worm infestations is by cutting off leftovers.

How To Avoid Aquarium Pests Infestation?

Prevention should always be the priority when dealing with potentially parasitic organisms. However, worm invasion can affect any aquatic system. In actuality, no system can be worm-free. The greatest part of eliminating these worms by any fish keeper is to appropriately isolate those new, ill, or damaged fish and to support a healthy fish immune system with sufficient nutrition, clean water, and suitable habitat.

The quarantine technique is also a good way to keep the reef tank worms away from the environment be it fish, insects, or any other living organism in the tank. If you aren’t sure about your aquatic environment, the suitable accessories for the fish tank, best fish food to avoid growing tapeworm in goldfish or other pong fish then it is recommended to visit your aquatic veteran and ask them about this. If you like what we posted, keep browsing for more pet care guides.

About the author

Arlene S. Lane

Arlene S. Lane is a veterinary technician and hospital manager with over 12 years of experience. Arlene has been contributed expert content to The Pet's Rise for over 10 years.
Arlene has worked in veterinary medicine since 2017. Arlene's veterinary experience ranges from routine wellness care and preventive medicine to emergency and specialty care, where she has performed duties ranging from specialized nursing to clinical administration.

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