What Is Camallanus Red Worm? (And How To Treat It)

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Treating Camallanus Red Worm can be especially tricky. It is highly contagious, can be easily spread between aquariums, and is really prevalent in fish that eat from the bottom of the aquarium or who ‘scavenge’ for food in the substrate.

I remember the first time I had an outbreak of Camallanus Red Worm in my fish room. I didn’t know I had it until a number of my guppies died suddenly. When I removed their bodies they had small red worms sticking out of the bodies. Camallanus Red Worms spread from tank to tank really quickly!

What Is Camallanus Red Worm?

Camallanus Red Worms are small, parasitic nematodes that live in the intestinal tract of fish. Camallanus Red Worms are easily spread from fish to fish. Symptoms of Camallanus Red Worm include a swollen abdomen, loss of appetite, and tiny red worms protruding from the vent (anus) of the fish. Camallanus Red Worms are their characteristic red color due to the consumption of blood from the host fish.

How Does Camallanus Red Worms Enter Our Aquariums?

Camallanus Red Worms are most often associated with livebearing fish including Guppies, but they can infect any fish, and the worms have been recorded in countless species of fish around the world.

In the wild, Camallanus Red Worm is only found in freshwater environments. In our aquariums, however, they are easily transferred over to marine aquariums as well.

Camallanus Red Worms are highly contagious and often spread from fish to fish in the tanks of importers, wholesalers, and stores. Cross-contamination can also occur through using the same equipment in multiple tanks, including nets.

Even quarantining new fish doesn’t also help prevent Camallanus Red Worms from entering our aquariums.

Research into Camallanus Red Worm and their spread in the hobby has shown that the worms travel in ‘intermediate’ hosts such as crustaceans. Other research and anecdotal evidence from both breeders and hobbyists suggest that the worm can be introduced when feeding live foods and with live plants.

How Do Camallanus Red Worms Affect Fish?

In the early stages, it can be hard to tell that your fish are infected with Camallanus Red Worms. There may initially be no outward signs. The first sign something is wrong with your fish maybe their lack of interest in food. As the nematodes multiply inside the fish’s intestine, the fish’s abdomen will become noticeably swollen.

Small, wire-like red worms will begin to protrude from the vent or anus of the fish. Eventually, the fish will die. The dead fish will often have worms protruding even after death. If you gently squeeze the dead fish, a large number of worms will come out of the dead fish’s vent.

The main symptoms of Camallanus Red Worms:

  • Bloated abdomen
  • Lack of interest in food
  • Swimming on the spot (shimmying)
  • Red, wire like worms protruding from the vent (anus)

Healthy fish, being kept in a well-maintained aquarium can usually put up with a small infection of Camallanus Red Worms. In fact, it is entirely possible for the fish and worms to like in unison without the fish keeper ever knowing of the Camallanus Red Worms presents.

Overcrowding of the aquarium, poor water conditions, and poor diet can cause the Camallanus population to get out of hand and begin killing the fish.

What Is The Lifecycle Of Camallanus Red Worms?

Camallanus Red Worms have three main stages to their lives:

  • The free living stage: After successfully mating, mature female Camallanus Red Worms will produce ‘first-stage’ larvae. These larvae find their way into the water column when the host fish defecates. These larvae will quickly move down and settle in the substrate where they will ‘wriggle’, hoping to entice passing crustaceans to eat them.

  • Moulting Larvae Stage: Once consumed by a crustacean, the larvae feed in the host crustaceans’ gut. Here they remain, moulting twice until they reach ‘third-stage’ larvae size. At this point the larvae become inactive, waiting for the host crustacean to be eaten by a fish.

  • Mature Adult Worm: Once the larvae detects its host has been eaten by a fish it moults into a mature male or female Camallanus Red Worm. At this point, now sexually mature, the process will begin again.

The lifecycle of the Camallanus Red Worm is massively dependent on water temperature. Research has shown that in water which is 77°F (25°C) the whole process takes around 28 days.

Image Source: chewy.com

There are several different species of Camallanus Red Worms, and all need to go through the lifecycle detailed above, with the exception of Camallanus cotti. Recent research has shown that this species can complete its life cycle without the host crustacean.

How To Treat Camallanus Red Worms

There are a number of ways to treat Camallanus Red Worms. Fenbendazole, levamisole, and praziquantel have all been used to treat fish infected with Camallanus Red Worms.

Many of these treatments don’t actually kill the worms, but rather paralyze them, allowing the fish to excrete them before they have a chance to complete their life cycle. Because the worms are passed rather than killed, treatment should be accompanied by thorough gravel vacuuming. The worms will be excreted as either pink or white worms.

It is often advised to treat 3 times over a three-week period. This allows the medications to kill the worms that may have been in the larvae stage when the first and second doses were administered.

Treatments For Camallanus Red Worm In UK

In the UK and Europe, eSHa Labs produces a medication called eSHa ndx. eSHa ndx has Levamisole as the active ingredient. eSHa ndx has in my experience been very effective in the treatment of Camallanus Red Worm. I have more information on eSHa ndx in this article.

My Final Thoughts On Camallanus Red Worms

If your aquarium has ever had an outbreak of Camallanus Red Worm, you will no doubt be aware of how quickly it can spread through your tank and just how many fish it can kill, often before you know what the problem is.

Camallanus Red Worms are surprisingly common in our aquarium fish, especially in guppies, mollies, goldfish, and other livebearers. Left untreated, an outbreak of Camallanus Red Worms will devastate your aquarium.

To prevent such an outbreak, always quarantine your new fish and make sure you practice good aquarium husbandry such as regular water changes, frequent gravel vacuuming, and feeding your fish good quality foods.

The ultimate answer to dealing with Camallanus Red Worm is quick identification of the problem followed by an appropriate course of suitable medication.

About the Author

I’ve been keeping, breeding, and showing tropical fish for nearly 30 years. Over that time I’ve done it all! I’ve had great success and I’ve made some really foolish mistakes (like the time I bought an Asain Walking Catfish). Read more…
Richard James

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