Shrimp Diseases and Treatment

Introduction

Shrimp diseases are the primary cause of shrimp deaths while breeding and keeping shrimps. Thus, it is substantial to know how to treat shrimps when necessary. But, before diving into the disease types it is significant to tell more about shrimps.

Shrimps are aquatic crustaceans that play a significant role in the food chain in nature. They are a vital food source for fish and birds. Shrimps are used not only for hobby purposes but also commercially, and they are highly preferred creatures to keep. Therefore, their care becomes critical for successfully keeping and breeding them. Aquarists are facing a variety of diseases that make shrimps suffer or threatened. So, what types of diseases threaten shrimps, which are substantial in many respects, the effects, and how to treat them? These are the main questions that we are going to discuss in this article.

Shrimp Diseases

Vorticella

Description
shrimp-diseases-vorticella-close-up

Vorticella is a single-celled, eukaryotic cilium from the Vorticellidae family that approximately has 200 known species that live in the freshwater. It is also known as Bell-Animalcule. It has stalks that allow it to adhere to surfaces. Vorticella has dimensions that can reach 30-40 microns. It can tolerate a wide range of water temperatures like 23-35°C that makes it highly adaptive for living in most aquariums.

There are several life phases of this parasite as free-swimming, reproduction, or living on the host. The first life phase of the Vorticella is called the free-swimming phase. They produce the stalks at this stage and attach themselves to a surface, plant, or shrimp using these stalks.

A limited number of parasites are not harmful to shrimp. However, the increase in the number may result in death, as it will cause anorexia. On the other hand, a high parasite population can adversely affect the oxygen level in the tank.

Causes and Diagnosis
shrimp-diseases-vorticella-shrimp-1

It is a disease that is easy to detect visually. This parasite is colorless and has the appearance of fungus. Sometimes it can take a color close to yellow. It especially settles in the nose of the shrimp, antennae, or mantle. Apart from the visual changes, the parasite also causes several changes in the behaviors of shrimps. The most common of these is swimming abnormality. The shrimp cannot swim properly and will begin to circle. Anorexia and stress are other symptoms caused by the parasite.

Poorly established aquariums and poor water quality are the primary causes of this parasite settling and develop. New fish, shrimp, decorations, or plants brought into the aquarium from outside may also carry this parasite. Afterward, under proper conditions such as poor water quality, it develops and spreads in the aquarium and infects the shrimps. To prevent such infections, sterilization, and quarantining is the best practice to always keep in mind.

Prevention and Control

There are multiple methods to treat this disease, and each method has its advantages and disadvantages.

Potassium permanganate is the first of these treatment methods. It can be used by evenly distributing it on every surface, considering the tank dimensions. It is necessary to change 10 percent of the water after six hours of using the potassium permanganate. The next day it needs to be repeated.

Also, treating shrimps individually is another option. After the potassium salt in the water is completely dissolved in a separate container, the infected shrimp should be taken out of the tank and kept in this solution for 15 minutes before moving back to the main tank.

It is substantial to note that potassium permanganate loses its potential when exposed to light. For this reason, the application of this process should be done while the aquarium lighting is off. Also, if possible, covering the aquarium with a cloth to prevent light exposure during the treatment will increase effectiveness.

As a result of this treatment, all Vorticella parasites will die off. However, this treatment method has some harms. Potassium permanganate kills all good and bad bacteria in the tank as well. Second, it causes a dramatic decrease in the dissolved oxygen level in the tank. During the treatment, the tank requires well aeration with an increased level of its regular level. The treatment can also damage algae and aquarium plants by reducing photosynthesis ability. Also, aquarists have reported that all snails in the aquarium died during potassium permanganate treatment.

The most reliable treatment method is aquarium salt for Vorticella. A tablespoon of salt completely dissolved in a separate container with 1 liter of water. The infected shrimps are taken into the salt solution for a short bath. After 1 minute the shrimps are returned to the main aquarium. Even if the lower dosage removes the Vorticella on the shrimp, it may not clean the aquarium. For this reason, the dosage can be adjusted so that 1 tablespoon of salt is added to every 19 liters of aquarium water to treat the complete aquarium. Water changes up to 20 percent of the total water amount can be made after the third day of the treatment.

Copper sulfate is a substance that is suitable for the treatment of many diseases. However, many aquarists avoid using it because copper is a heavy metal and it causes some damage to the livestock. Also, copper can remain in the tank for 1 month after it is used for the treatment. Also, it is the least effective method for treating vorticella.

Below are some reference values of copper are listed that can be tolerated for some aquatic creatures.

Shrimps 0.03 mg per liter
Algae and bacteria 0.08 mg per liter
Fish, snails, and plant 0.10 mg per liter

*Note: Snails, plecos, and ancistrus species that have an exoskeleton may be sensitive to copper.

Because the dose adjustment can cause major problems, it is better to use commercial drugs available in the market for average aquarists. It is easier to follow the instructions available on the packages. But for experienced hobbyists, it is a cheaper and applicable option to treat with the chemical itself.

Individual treatment is also applicable for treating with copper sulfate solution. Once the proper amount of chemical is completely dissolved in a separate container, the infected shrimp should be taken out of the tank and kept in this solution for 30 minutes before moving back to the main tank. It is recommended to apply treatment in a separate quarantine tank, not in the main tank, due to its high risk.

Substances such as malachite green, formalin, or iodinol can also be used for the treatment. What should not be forgotten at this point is that since each treatment method has various advantages and disadvantages, the decision should be made by considering all livestock in the aquarium while treating the main tank. Some chemicals and their dosage are given below for reference.

KMnO41 ppm 30 min
CuSO4 (Copper sulphate)50 ppm 45 min
Formalin50 ppm 15 min
Malachite green100 ppm 15 min
Acriflavine100 ppm 30 min
Methylene blue100 ppm 6 h min
Flavone50 ppm 10 min

Prevention is always easier than treating a disease. Keeping the water quality high is the most significant factor in preventing the disease as well as quarantining new creatures before introducing them. Regular water changes are the main element of water quality with good filtration.

Scutariella Japonica

Description
shrimp-diseases-Scutariella-Japonica-close-up

Scutariella Japonica is another parasitic disease seen in shrimps. This parasite belongs to the Scutarielloidea family which is a species of flatworms. Although they resemble Planaria, they behave differently from them. They can reach a size of about 1-2 mm and have a white color.

Causes and Diagnosis

Visual detection of this parasite is easy as it is in other parasites. They are usually found on the shrimp’s head, mantle, or gills. These parasites are more often located close to the eyes. Also, they can rarely nestle on the legs or other parts of the body. On the other hand, they lay their eggs on the back of the shrimp’s head.

shrimp-diseases-Scutariella-Japonica-1

They are often confused with the Vorticella parasite, but there is no link between them. Scutariella is opaque and whiter than Vorticella. They usually do not cause the death of the host since they do little harm. For this reason, they can be considered almost harmless. But the higher their number, the more likely they may harm the host. According to researchers, the increase in the number of parasites disables the shrimp’s mobility and makes it difficult to breathe. And this could lead to death.

It is not clear why these parasites occur. But, as with the Vorticella, poor water conditions and other aquatic creatures or decorations placed in the tank from outside can carry and introduce the parasite into the aquarium.

Prevention and Control
shrimp-diseases-Scutariella-Japonica-2

Aquarium salt, which is also used in the treatment of Vorticella can be used for this parasitic infection. Apart from this, there are also some specialized medications available in the market for treating Scutariella.

Usually, Scutariella clings to shrimp molts. This is one of the ways the parasite reproduces in the tank. For this reason, molts must be collected quickly from the aquarium while observed. Otherwise, small amounts of parasites can colonize on it.

As with the Vorticella, buying shrimp from a safe place, keeping the newly purchased shrimp in quarantine, or sterilizing the new decoration materials to be placed in the aquarium are simple and easy ways to prevent the disease.

Bacterial Infections

Description

Bacterial infections are another factor that affects shrimp health. The most known of these bacterial infections are the Micrococcus infection belonging to the Micrococcaceae family. These gram-positive bacteria can live in a variety of environments such as dust, soil, and water.

Causes and Diagnosis
shrimp-diseases-bacterial-infection-shrimp-left

Unfortunately, bacterial infections are so difficult to detect visually. The diagnosis of the disease can be made with microscopic examinations. On the other hand, the histological study is another method to diagnose the disease. If the shrimp species has a transparent appearance and its internal organs are visible, the disease can be visually recognized. While the internal organs of healthy shrimp are black, infected ones have a color close to pink. At the same time, inflammation may be seen in the affected organs. (Shrimp at the left with infection and the healthy shrimp on the right)

Infected shrimps die, usually within 2-4 days after symptoms appear. The sudden death of the shrimp is and enough reason to suspect a bacterial infection. Shrimp may also show color changes or may lose limb or antennae.

Prevention and Control

There is no effective treatment method for this disease. In some recent researches, it is shown that oregano oil is effective on bacterial diseases and harmless to use with shrimp. But it is not widely tested or common in the aquarium hobby. Nevertheless, there are still several ways to control the bacterial diseases in the tank.

The disease known with the names chitinolytic bacterial disease, shell disease, brown spot disease, black spot disease, burned spot disease, rust disease is also a bacterial disease common for the shrimp species. The cause of the disease is chitinolytic bacteria (Gram-negative rods) including Vibrio spp. (Benekea spp.), Pseudomonas spp., Aeromonas spp., Spirillum, spp. and Flavobacterium spp. The common visual symptom is the erosion of chitin demarked by dark brown to black pigmentation. The disease progresses by necrosis, inflammation, and subsequent melanization of the body surface and appendages. The treatments below are also applicable for this disease.

• If the disease is suspected, it is recommended to change 80% of the water amount daily, sterilize the equipment and tank to control bacterial infection. This is a kind of reset for the aquarium but will help to save the remaining shrimp population.

• Hydrogen peroxide is another method that can be used to control the disease. Add 1 ml of 3% concentrated hydrogen peroxide to every 4 liters of water. This process should be repeated for 5 days daily basis. After 5 days, another %50 percent water change is necessary to remove dead bacteria and chemical residue.

• Applying UV light filtration is another method to keep bacterial, fungal, and other kinds of biological diseases under control.

Based on some hobbyists’ experience (Pals from SKF – https://skfaquatics.com/forum/forums/topic/5052-shrimp-diseases-and-diagnosis/ ) and as per veterinarian advice, applying a 3 dose of 1000mg / 40 liters Oxytetracycline treatment is effective on gram-negative bacterial infections and stops the deaths in the starting from the second day of the first dose. As per the instructions given, the tank was dosed with the above-mentioned dosage on the first day. The following day a %50 water change was made, and a full dose applied again. After two days, another 30-40% water change and one more full dose applied. Waited for 2 days and the last 30% water change was made. The repeated doses are applied to prevent the development of antibiotic-resistant bacteria and completely kill them.

Note: After applying an antibiotic treatment, we suggest paying attention to the drain water since it may still contain some live bacteria resistant to the antibiotics. If possible, UV filtering the drain water in a separate container for 2 days before permanently flushing the water to the sewer system will prevent untreatable future diseases. Another alternative can be sun drying the flush water.

In some cases, bacterial infections developed as secondary because of a primary parasitic or fungal infection. For this reason, it is substantial to check the shrimp daily to detect any primary infection to treat the original cause earlier than it develops.

Fungal Infections

Description

Mycosis is also known as “fungal disease” and it is a significant disease that has harmful and fatal effects on shrimps. This fungal disease can be found anywhere in the world. The spores that are usually found in the foods that the shrimp eat are the primary cause of the illness in shrimp with weak immune systems.

Causes and Diagnosis
shrimp-diseases-shrimp-fungus-1

These fungi, which in most scenarios involve the internal organs, cause the death of the shrimp and are very difficult to detect visually. This disease can be detected with microscopic examination. On the other hand, Saprolegnia and Achlya are other species of fungi that cause external infections. These cause whiteness on the head and abdomen area of shrimp. They can be easily identified visually without a microscope. Such kinds of fungal infections are effective when the shrimp’s immune system is lowered. These infections can occur after situations such as the molting phase or after injuries, and the symptoms are visible by the naked eye.

Prevention and Control

Fungal diseases are likely to result in death. Shrimp suspected of being sick must be quarantined to avoid the infection to spread in the tank. During the quarantine period, treating with proper medicines on the market is ideal for shrimps. The application methods of these medicines may vary according to the type of active ingredient of each. So, it is substantial to get help from a specialist before selecting the drug and treatment.

Application of Malachite green at 0.05 mg per 1 liter of water is one of the treatment methods for fungal diseases. This process should be repeated for seven days following by a 50% water change every day.

One of the most effective treatments available is a commercial product called JBL’s Fungol for fungal infections. Information on how to use this medicine exists on the drug package.

It is so difficult to diagnose fungal diseases that are not visible from the outside. For this reason, sudden deaths should be suspected as internal fungal infections. Afterward, the treatment can be applied accordingly.
Regular water changes and high-quality foods will help to prevent such diseases. It is vital to keep the shrimp immune system to prevent fungal diseases.

Muscular Necrosis

Description

The word meaning of “Necrosis” is the death of a group of cells. On the other hand, muscular necrosis is not a disease but a symptom caused by underlying reasons. Therefore, the underlying causes should be investigated when diagnosing the disease.

Causes and Diagnosis
shrimp-diseases-muscular-necrosis

Muscular necrosis should be suspected if the shrimp have dorsal or muscular tissue whitening in the shell is observed. Bacterial infections, Myxosporidien, or poor tank conditions are the reasons that trigger this disease. Also, insufficient oxygen, sudden pH changes, or inadequate nutrition can cause the disease.

Prevention and Control

For the treatment and control of the disease, the shrimp with Muscular Necrosis should be quickly taken out from the tank and put into quarantine. If the underlying cause of the disease is a bacterial infection, the treatments mentioned under the bacterial infections section should be applied accordingly. Parameters such as pH values, temperature, water hardness, and nutritional quality in the water should be controlled and adjusted to proper levels where the shrimp can grow healthy.

Conclusion

Shrimps are raised for both hobby and commercial purposes as food all over the world. Parasites, bacterial, fungal, or environmental factors can cause these excellent animals to get sick and die. Apart from the financial losses, the death of a living creature is always sorrowful. As seen in the diseases mentioned above, mortality probability could be higher in some cases. The most critical points in all diseases are observation and prevention. Routine and daily monitoring of shrimps allows you to detect the disease at an early stage and take quick action before it spreads. Also, it is always significant to keep the water quality and environmental conditions at comfortable and suitable levels for the shrimp.

Image Source:
http://cfb.unh.edu/
https://skfaquatics.com/
https://www.aquaportail.com/
https://myshrimphouse.com/

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