Understanding Dwarf Shrimp Diseases and Parasites  

No shrimp owner wants to see their shrimps develop unexplained and sometimes brutal diseases. However, they are extremely common, and in most cases curable. The first step to understanding and treating dwarf shrimp diseases and parasites is learning to recognize them. Are your shrimps suddenly dying? Are they changing in color or developing strange dots and spurs on their bodies? This article will give you a better understanding of how to recognize the diseases and parasites your shrimps may be suffering from.

Vorticella    

Vorticella is one of the most common parasites in shrimp tanks. It looks like white mold growth on the body of the shrimp. Areas of fluffy white growth may also be observed on the shrimp’s head and at the tip of the nose.

Because of its appearance, vorticella are often mistaken for a fungus when they are better described as protozoa. There are over 200 known species with at least 16 known types of Vorticella, which are classified as heterotrophic organisms, meaning that they feed on bacteria. Vorticella will settle on freshwater plants, algae, rocks, shells or crustacean animals, such as shrimp.

As protozoa, Vorticella reproduce by dividing themselves. The new protozoa, which is created by the division of the “parent” will float into the water until it finds something to leech onto.

For shrimp, Vorticella can be deadly. Left untreated, it could cause various health problems and eventually death.

Treatment possibility: Fortunately, Vorticella is curable. You can read more about it in my article “Shrimp Vorticella Parasite. Treatment”. 

Some medicine (links to check the price on Amazon):

• Paraguard
• Aquarium Solutions ICH-X
• Freshwater aquarium salt
• PIMAFIX

Scutariella Japonica    

Scutariella Japonica is possibly the most common and most discussed shrimp parasite. A Scutariella Japonica is a type of flatworm or parasitic nematode. It is classified in the following categories and sub-categories: plathelmintae/tubarellia/temnocephalidae/scutarielloidea. This animal is classified as a “parasite” by shrimp keepers because it lives and thrives by damaging the gills or mantle of the shrimp and sometimes even lead to their death.

The first sign of infection of a shrimp by Scutariella japonica is the appearance of a small white stick-like growth of about 1 to 2 millimeters on top of a shrimp’s head. As I have just said, these parasites live not only on the heads of shrimp but also in their gills. However, they are very rarely found toward the legs of the shrimp or the lower part of their bodies.

Those parasites grow, thrive, and reproduce inside of the shrimp. This means that they also lay eggs inside the shrimp’s head or in the gills region (read more about shrimp anatomy). After the shrimp molts, the eggs are liberated, open up, and go on to colonize more shrimps. Although those eggs are small in diameter, there are often several of them forming a noticeable white formation around the shrimp’s head. This makes them easy to spot even without using a microscope.

It is also important to note that in small quantities, these parasites will cause no great harm to the shrimp and the only problem is on an aesthetic level, as it affects the appearance of the animals. However, if the parasites reproduce at a steady pace and colonize more hosts, they can cause serious health problems and really be considered a disease.

Treatment possibility: Scutariella Japonica can be cured. You can read more about it in my article “Shrimp Disease – Scutariella Japonica. Treatment”. 

Some medicine (links to check the price on Amazon):

• Paraguard
• Freshwater aquarium salt
• Panacur C
• Canine DeWormer

Holtodrilus Truncates

Holtodrilus truncates (shrimp worms) are small, worm-like obligate epibionts (organisms living on other organisms, basically, parasites) of crustaceans, mainly crayfish and shrimp. These worms do not appear to prefer to anchor to the rostrum, instead of anchoring under the shrimp right between the pleopods.

These parasites are a new threat that came to use from Asian aquaculture ponds. Shrimp worms can affect shrimp wellbeing by causing distress which leads directly to shrimp weakness, loss of color, and even casualties.

Treatment possibility: Fortunately, Holtodrilus truncates worms are easy to remove. You can read more about it in my article “Holtodrilus Truncates – Parasites in Shrimp Keeping Hobby”. 

Some medicine (links to check the price on Amazon):

• Freshwater aquarium salt

Bacterial infection    

Bacterial infections are subtle and act quickly. The outbreak of Bacterial infections can lead to massive mortalities of the shrimp. You may only notice that your shrimps have got sick with one when several of them start dying all of a sudden.

In shrimps that are transparent (like Amano shrimp or Ghost shrimp), the infection can sometimes be observed by a change in the appearance of their internal organs. For example, they might look inflamed or swollen, and even sometimes turn to black.

Unfortunately, for other types of shrimps, the infection may go entirely unnoticed until death. In fact, you may not even notice what caused death and blame water parameters (PH, GH, KH, TDS, Nitrate, etc), molting issues,  copper, etc.

Because noticing a bacterial infection generally means that the shrimp has been infected for a long time, the shrimp only has a few days to live once it has been diagnosed with a bacterial infection. The problem is that I do not know any organization that can do such things for ordinary shrimp keepers.

Treatment possibility: In conclusion, we do not know much about Bacterial infection, we cannot diagnose it fast enough and there is often no treatment for our shrimp.

Chitinolytic Baсterial Disease

Chitinolytic bacteria affects the outer organs of the shrimp, differing from bacterial diseases, which only affect inner organs. Under the umbrella name, ‘chitinolytic’, many types of bacteria are grouped, among which Benekea spp, Pseudomanas spp, Vibrio spp, Flavobacterium spp, Spirillum spp, and Aeromonas spp.

The main criterion of diagnosis of this disease is spots, dips, and a general erosion of the outer membrane of the shrimp. The dotted appearance that it gives the animals has given this type of infection many names, among which “Brown spot disease”, “Burned spot disease”, “Black spot disease”, “Rust disease” and “Shell disease”.

Not only does this infection affect the structural integrity of the shrimps’ outer membrane, but it also makes them a lot more vulnerable to further infection.

Treatment: You can find on different sites some ways to treat it but to tell the truth, I know only one treatment that can be used against Rust disease – hydrogen peroxide (H2O2).

You can read more about it in my article “Rust Disease in a Shrimp Tank. Treatment”.

Fungal Infections    

Although they are more common with fish than shrimps, fungal infections are a real possibility and sometimes a powerful killer of shrimp. To understand fungal infection, it is first important to understand the role of fungi in the lives of shrimp:

fungi are organisms that belong neither to the plant kingdom nor to the animal kingdom. On earth, we know fungi best in the form of mushrooms, but there are actually thousands of different species of fungi. Any kind of water zone in which living animals are present is sure to contain a good amount of fungi as well. Most of the time, that fungi is not dangerous or harmful.

However, in some cases, fungi can cause an infection known as ‘mycosis’ (‘mycosis’ is the same diagnosis given to people who struggle with conditions such as Athlete’s foot). In shrimps, mycosis can deteriorate internal organs, and even cause death.

Most shrimps are able to resist fungal infections well, granted that they have a solid immune system. When shrimps are injured, are recovering from another disease, or straight after they have molted, they are particularly sensitive and likely to develop a fungal infection.

Fungal infections and Diagnose

Fungal infections are particularly hard to diagnose when they affect the internal organs of the shrimp. In fact, they may only be noticeable with a microscope, which is not readily available to the standard amateur shrimp keeper.

However, fungal infections such as “Achlya” or “Saprolegnia” which affect the outer membrane of the shrimp can be visible to the naked eye in the form of white residue. Shrimps that have been attacked by those fungi will develop a cloud-like white growth on the outer part of their bodies.

Not only are superficial fungal infections easier to diagnose, but they are also easier to cure. In some cases, the shrimp will molt, and the fungal infection will disappear with the molted skin itself.

However, if the infection is still there are several medicines, which can help you.

API Pimafix (link to check the price on Amazon), according to API company, is completely safe with invertebrates such as snails and shrimps. It will not harm the biological filter – the bacteria in the biological filter are quite different from those that are found on the fish. It will not harm plants.

Proper usage:

1. Add 5 ml per 10 gallons of aquarium water.
2. Dose daily for 7 days.
3. After 7 days, make a 25% water change.

jbl Fungol will also treat external mycoses (fungal infections). However, be very careful, according to the manufacturer, “Invertebrates in freshwater (shrimp, crustaceans, snails, etc.) may exhibit intolerances”. Therefore, if you decide to use it start with less then half a dose and increase cautiously.

Treatment possibility: potentially curable. 

Porcelain disease

“Porcelain disease” is the result of infection by the single-celled protozoan Thelohania contejani (Microsporidia), and is only easily recognizable in the advanced stages, when the abdominal muscle, translucent in healthy individuals, becomes white and opaque.

This is a serious problem for several decapod crustaceans including shrimp, crabs, and freshwater crayfish.

The infectious stage is represented by the spore, which is highly resistant, persisting in the environment for long periods of time. Initially thought to be protozoans, new molecular biology data has suggested their affinity for fungi.

When the infection spreads, the parasite can be found in the gills, skeletal, cardiac, and intestinal muscles.

“Porcelain disease” usually only occurs with newly imported shrimp or with animals that have come into contact with these imported animals. It has not been proven so far that the disease also occurs spontaneously.
At first, the infected shrimp will lose some color. Then they turn milky white starting from the head. Next, infected muscles will not be able to move, and after some time shrimp die.

Note: The infection rate also seems to depend on the pH of the water. The lower the pH, the higher the risk of spreading “Porcelain disease” infection.

Important: Shrimp with such symptoms should be immediately removed from the tank.

Treatment possibility: Unfortunately, it is possible to treat this disease only in the early stages. According to the experiments, flake food soaked in the malachite green was effective against this parasite in several cases. However, no guarantee can be given.

In my article “Shrimp Vorticella Parasite. Treatment” you can find the list of medicines that contains malachite green. 

Medicine (links to check the price on Amazon):

• Paraguard

“Milk shrimp disease” or “Cotton shrimp disease”

It is very easy to confuse “Milk shrimp disease” and “Porcelain disease”. The difference is that unlike “Porcelain disease”, “Milk” parasite infects almost all body of the shrimp at once.

This disease is caused by Myxosporea, which literally eats the shrimp from the inside.

Shrimp with these symptoms usually die within a short time.

Treatment possibility: Myxosporea are very resistant and effective treatment is currently not known for the shrimp.

Epibionts, Dinoflagellate, and Ellobiopsid Parasites 

Much like fungi, there are hundreds of different sorts of epibionts, dinoflagellates and ellobiopsids living in the water. Not all of them are bad, and most are completely harmless. However, in some cases, epibionts, dinoflagellates, and ellobiopsids (sometimes also called ellobiopsidae which is more scientifically correct), act as particularly vicious parasites. They attack not only shrimps but also fish and a variety of other invertebrate animals.

Their method of attack is to settle into the shrimp’s digestive tract, muscles, blood, and even eggs, where they live using the shrimp’s inner resources. This causes the shrimp to weaken, become sick, and eventually die.

Although they are subtle, the presence of these parasites can be fairly obvious to the trained eye. These species reproduce by sending out spores which are then found on the outer membrane of the shrimp’s body. To be able to fight that kind of infection early, I strongly recommend that shrimp keepers familiarize themselves with the appearance of the spores of those dangerous parasites.

In order to notice the appearance of those parasites in a shrimp tank, you need to look out for cottony green or yellowish growth on the body of the shrimp. The texture will be very similar in appearance to a fungal infection, differing only in the color of the growth created. The most common place to notice the appearance of infection is in between a shrimp’s legs and around the swimmeretes.

Treatment possibility: Green fungus is extremely hard to treat. However, there is still a chance. You can read more about it in my article “Ellobiopsidae or Cladogonium ogishimae. Green Fungus in Shrimp Tank”. 

Some medicine (links to check the price):

• Kordon Rid Ich Plus
• Seachem Paraguard
• Hydrogen peroxide.

Muscular Necrosis

Muscular Necrosis is a common disease in shrimps. It is characterized by loss of color on the body of the shrimp, which goes together with the appearance of white or milky colored spots on the lower end of the shrimp’s body.

The word “Necrosis” comes from the Greek word “Necros” which signifies “Death”, and refers to a disease in which the cells of an animal die off. The white color on the shrimp that you see making an appearance is actually only a symptom of a larger problem, which is the death of cells in the muscles, hence the name “Muscular necrosis”.

Some shrimp keepers assume that Muscular necrosis can be caused by inappropriate water parameters, lack of nutrients, bacterial infection, etc. However, nobody knows for sure. Therefore, without understanding the cause it is not possible to find the cure.

Treatment possibility: not possible.

Parasites

Parasites are not actually always considered to be a disease for shrimps. In some cases, a parasite will choose to live on a shrimp and cause it no harm whatsoever. In some circumstances, the relationship between the shrimp and its parasite can even be called “Symbiotic” because they both benefit from being in relation with one another.

However, in some cases, a parasite can be manifested as a disease. It will weaken the shrimp or damage its internal organs, and, depending on the species, can even lead to the death of the shrimp. Common parasites for freshwater shrimps include scutariella, flatworms, leeches, etc.

Planaria

These worms are absolutely hated by most aquarists. However, if you are overfeeding your shrimp there is a very high chance that Planaria will visit your tank eventually.

Although, they cannot catch healthy shrimp they can be a problem for the shrimplets and molting shrimp. So they do actively prey on some things.

Do not try to squash or cut them. Thanks to their ability to regenerate, they will grow back the missing part. As a result, you will get 2,3,4, etc. Planaria in place of the one.

Treatment possibility: very good chances. You can read more about these worms in my article “Planaria and Shrimps. How to remove them”.

Some medicine (links to check the price on Amazon):

– Benibachi 
– Dog Dewormer
– Panacur C

Hydra

Unfortunately, Hydras are also common visitors in our tank. This tiny predator feeds on small aquatic invertebrates that are paralyzed by the stinging cells.

Of course, one or two stings will not harm adult shrimp. The problem is that if you saw one Hydra it means that there are many more unnoticed. That can become dangerous even for the adult shrimp.

Keep in mind that their numbers grow exponentially! Every 2 – 3 days Hydra makes its copy. Thus, only 1 Hydra can turn into 4 000 in just 3 months.

Treatment possibility: very good chances. You can read more about it in my article “Hydra in a Shrimp Tank. Treatment”.

Some medicine (links to check the price on Amazon):

• Hydrogen peroxide
• Benibachi
• Dog Dewormer
• Panacur C

Dragonfly Nymph and Damselfly Nymphs

A Dragonfly or Damselfly nymph is not so much a disease or a parasite as it is a dreaded predator for the freshwater shrimp. Dragonflies can live in close proximity to shrimps and prey on them, eating both the babies and the adult specimens of the species.

The main way to tell if a dragonfly nymph may be affecting your shrimps is if you notice a lot of sudden deaths (disappearances). You may also want to familiarize yourself with the appearance of these animals. Knowing how to spot them will make it easy to tell if the death of your shrimp is caused by a predator, or finds its cause in another disease.

Treatment possibility: besides manual removal, it is almost impossible to get rid of Dragonfly Nymph and Damselfly Nymphs in a shrimp tank.

You can read more about it in my article “Dragonfly and Damselfly Nymphs. Monsters in Shrimp Tanks. Treatment”.