How to get rid of Nemerteans
Pictures: Michaël Baele, unless mentioned otherwise.
I bet that everybody knows them, those slimy little worms crawling against the glass of a terrarium. Whilst they may cause many victims amongst fruit flies and other food animals, they fortunately pose no threat to frogs. I have tried many times to kill them, but could not find a product strong enough, until by chance, I discovered a very effective product to help me get rid of those troublesome little worms, the Nemerteans.
Description of the Nemertean
Nemertea is a phylum of invertebrate animals also known as ribbon worms or proboscis worms. Most of the 1,400 species are marine, with a few living in fresh water. A small number of terrestrial forms also exist.
Nemerta can be found in all marine habitats (including the world’s oceans) and are named after Nemertes (one of the Nereids of Greek Mythology). Alternate spellings are: Nemertini, Nemertinea and Nemerta.
The name of Nemertean, or ribbon worm, refers to their anatomy. They are long, thin and distinguished by the presence of an eversible proboscis, which they use for catching prey. They are un-segmented animals with a body that can be flat or cylindrical and, they can range in size from 5 mm to over 30 metres long. They are very “stretchy” and can be lengthened up to double their normal size. Some are also very colourful, for example bright orange, yellow or red.
Their proboscis is retractable and can be retracted using the retractor muscle. In some families, the proboscis is armed with a sharp stylet, which may be poisonous.
Most nemerteans are carnivorous and predatory, they hunt for segmented worms, little crustaceans or insects. I have noticed that they do not really hunt for fruit flies, which possibly means that any flies touching the worm by accident are trapped in the sticky secretion on the proboscis, which is wrapped around the prey.
The circulatory system of nemerteans is closed, as is the digestive system, which includes a separate mouth and anus. The nervous system includes a brain and several nerve cords. Nemertean worms are unique in possessing a "cerebral organ" - a sensory and regulatory organ closely associated with the brain.
Nemerteans often have numerous gonads and most species have separate sexes, although all freshwater forms are hermaphroditic. Fertilisation is usually external, though some species have both internal fertilisation and live birth.
Starting a great hobby
I started to keep terrarium animals about 14 years ago. It all began when I was visiting a friend who had been keeping frogs for some time. In keeping with many amateurs, I created my first terrarium to keep animals that do not require complicated care, such as lizards and geckos. At that time, there was no question of disease or vermin in my terrariums. Everything went well and after a period-of-time, I decided that I wanted to learn more about looking after frogs, particularly poison frogs.
Inspired by their behaviour and their most beautiful colours, I became very enthusiastic about them and searched many specialised stores to find specific professional literature about frog terrariums. After spending considerable time reading up on the subject, I was finally ready to start my first frog terrarium and of consequence, bought my first group of poison frogs: a group of six P. Bicolor. Following on from this, I bought more and more species of poison frogs.
During the first couple of years, I had no troubles at all in any of the terrariums. No disease or vermin of any kind, everything was going very well and as such, I decided that I was ready to create a few more terrariums.
A weird animal.
Whilst experimenting with new containers, they must have entered the frog room, those strange little animals, the nemerteans. I suspect that new plants or frogs brought them into the terrarium, as any other scenario seems to be impossible to me. All the material used to create my terrariums was always well disinfected and/ or dried out. Xaxim, Yanti wood and peat were always dried out or even heated.
At first, the worms appeared only in one of the nine terrariums and for a while, it stayed that way. .Furthermore, they were not too numerous, as they appeared in a terrarium with Pumilio frogs which were fed for most of the time with springtails.
Unfortunately, whilst creating the frog room, some plant cuttings moved from the infected terrarium to the others, so you can imagine what happened...
Shortly after this, the nasty worms appeared in almost every terrarium. During the day, they were crawling most of the time on the pieces of banana used as bait for the fruit flies. However, once the lights are out, you could see them crawling on the glass. I quickly established that the terrarium in which fruit flies were fed were the most infected. They were also more numerous during the humid period than dry season. At that moment, it seemed that the only efficient way to combat these worms was by removing the front glass and rinsing it with really hot water.
Saturday, 13th October 2007
On this very important day, a friend of mine (also a fellow frog keeper) came to see me. After having made some improvements to the critter boxes, we went to the frog room. Whilst inspecting the different terrariums, we passed the one with the couple of D. Tinctorius Patricia. Unfortunately, I had noticed earlier in the week that worms had infected them.
I told my friend that the treatment had already started (as I always have the necessary medicine in stock). Checking up on the frogs, I suggested to my friend that it could be worthwhile trying to put a drop of the product directly on to the nemerteans. I caught some of them and put them in a Petri dish where they were crawling around.
It is hard to believe but, shortly after having put a drop on the worms, they died immediately. I recall my friend saying, “it seems to me that they are not so happy anymore”. I was genuinely glad and relieved that I had finally found a way to exterminate the vermin that had caused me so much trouble for so many years. I tested this product immediately in 2 terrariums, in the first one I used the product to treat the frogs, in the second one a solution of 1ml of the product on 18ml water. The effect stayed the same, the only difference with the diluted solution was that the worms died only after some minutes.
The product I used is called L. Ripercol and is available at the veterinarian.
Active ingredient : Tetramissole
Dosage form: solution, 100 mg/l
Active against: XXXXXXXXXX
Administration: oral (for treatment of the frogs, on their back)
Dosage mg/kg during 2 days (for the frogs see text below)
Administration 2: XXXXXXXXXXX
Dosage mg/kg, during 2 days
I used a solution of 1ml L. Ripercol on 9 ml water to treat the frogs. For the worms, a solution of 1ml on 18 ml water is sufficient.
The diluted solution is also efficacious enough to sprinkle in the terrarium in order to prevent the worms, but only do this when the lights are out as the frogs will be in their sleeping place and as such, they will not get the product sprinkled on their backs. Please note that I only treat the bottom and side glass.
I also noticed that the product stays effective for some time, as the worms that are crawling against the glass in the morning also die off after a period-of-time. The treatment of the terrarium takes place the first, eighth and the seventeenth days of the month, followed by a rest period of 15 days. After this, sprinkle the terrarium one more time and the job should be done (the cycle of egg to adult worm should be stopped this way).
I really hope that this information can be of great help to many of you in order to rid you of these nasty little worms, the nemerteans.