Aquarium shrimp are known to be quite sensitive and easily stressed crustaceans. Therefore, when we see signs of stress in shrimp, it is also important to identify the source and resolve the problems before they become a major issue.
Some of the most common signs of stress in shrimp include lethargy, lack of appetite, loss of color, decreased growth, and molting problems.
Signs of stress in aquarium shrimp can be difficult to detect. They are often subtle and may not always be readily apparent.
In this article, I will discuss different signs that aquarium shrimp is stressed and what may cause it (I will also provide links to my other articles where I meticulously describe every mentioned reason). So, keep reading to learn more about it!
List of the Most Common Signs of Stress in Shrimp
There are several signs of a stressed shrimp. It can be:
- erratic swimming,
- loss of color,
- lack of appetite,
- decreased growth,
- molting problems,
- reduced fertilization success and decreased fecundity,
- loss of the eggs.
What is Stress for Shrimp?
Stress in aquarium shrimp is a physiological response to any harmful stimuli.
They can become overwhelmed when they experience any conditions that cause physical discomfort and trigger a physiological response.
Even short-term stressors for your pet may have adverse effects on their health. If it continues over time it may weaken their immune system, making them more vulnerable to diseases.
Too much stress on the shrimp may even cause deformities, higher mortality rates, and other major problems.
So, let’s list them in order of priority, as I see it, and tackle them one at a time.
1. Increased Movement
Increased movement (erratic swimming) is, probably, the easiest way to notice that something is wrong either with the aquarium water or with the health of your shrimp.
When shrimp experience significant stress, they often develop strange swimming and moving patterns. For example, if your shrimp are swimming frantically, bumping, or even scrapping their body parts intensively, it is a sure sign that they are under a lot of stress.
For more information, read my article “Shrimp Behavior: Why Do They Keep Swimming Around?”.
Lethargy is another easy sign of stress in shrimp.
Generally, shrimp are active animals. These little guys are always busy and their walking/swimming style has a mesmerizing effect. Actually, it is one of the main reasons why shrimp are so interesting to observe.
Therefore, when swimming and/or moving activity is decreased, it typically indicates a serious problem. Lethargy often comes right after increased movement. In this case, it is an indicator that the problem is acute and is only getting worse.
3. Loss of Color
Loss of color (fade in color) is the third obvious sign of the stressed shrimp.
It is really important to understand the reason your shrimp is losing their color as soon as possible as this can be a symptom of something much more serious.
There are many reasons that could be behind your shrimp loss of color, the most frequent ones include:
- shipment stress
- bad water parameters.
You can also read my article “How to Enhance Shrimp Color?”.
4. Loss of Appetite
Shrimp are great scavengers. In aquariums, they help to keep the tank clean, by grazing on algae or eating biofilm, detritus, uneaten fish food, dead animal or plant matter, etc.
Basically, they eat any organic matter that falls on the bottom of the tank. It makes them an amazing clean up crew.
Therefore, any loss of appetite is a common sign when shrimp feel stressed because it is a symptom that the shrimp’s immune and nervous system may be compromised.
When shrimp are under stress, their mechanisms for controlling food intake and appetite signals in the brain don’t work as they should.
5. Decreased Growth Rate
As with lethargy and increased movements, decreased growth is closely related to loss of appetite. In many cases, it is the next step of the same problem.
If the immune and nervous systems of the shrimp do not work, it will affect the shrimp’s intestinal metabolism. As a result, inappropriate feeding stuns their growth rate and weakens shrimp even more.
Generally, it takes around 75-80 days for the baby shrimp to become adults and reach maturity.
Any deviations will be an indicator of stress in shrimp.
6. Molting problems
Like all crustaceans, shrimp need to molt in order for their body to grow. However, molting is also the most dangerous part of a shrimp’s life because any disruption can lead to death.
Stressed shrimp may be already weakened by other factors (for example, inappropriate nutrition and immunity system (molting hormones) problems). Thus, it is way more likely to have molting problems.
Main reasons for molting problems in shrimp include:
- Unbalanced diet.
- Sudden changes in water parameters.
- Too big or too frequent water changes.
- Poor acclimation.
For more information, you can also read “Dwarf shrimp and Molting problems. The White Ring of Death”.
7. Decreased Fecundity and Reduced Fertilization Success
Generally, depending on the size, each female can carry up to 50 eggs on her swimmerets. Shrimp are prolific breeders once they are healthy.
Stressed shrimp do not breed much if at all.
Stress can hamper fertility. Incomplete fertilization of an egg, in which the egg lacks the genetic material to develop into an embryo will also lead to egg loss.
Read more about it in my article “Breeding and Life Cycle of Red Cherry shrimp”.
8. Loss of the eggs
Loss of the eggs is a sign of stress in aquarium shrimp that is also related to reduced fertilization success.
For more details, read my article “Missing Shrimp Eggs: Why This Occurs”.
Common Causes of Stress in Shrimp
The list of the most common causes of stress in shrimp includes:
- Poor water quality (primary stressors to the shrimp – Inadequate levels or range of the ammonia, nitrites, nitrates, low CO2, temperature, PH, GH, and KH),
- incorrect acclimation,
- large water changes (“White Ring of Death”),
- toxins (like copper, hydrogen sulfide, chlorine, chloramine, heavy metals, pesticides, etc.)
- parasites, infections, and diseases,
- incompatible tank mates.
As we can see, there are many signs of stress and some of them can also be difficult to detect right away. But what is even worse, it can also be hard to pinpoint the exact reason.
It is important to remember that stress can weaken shrimp’s immune systems and make them more susceptible to diseases. Chronic stress may inhibit the shrimp’s immune response and ability to fight illness.
Therefore, we need to know how to avoid, control, or treat all these things in shrimp tanks.
Shrimp can show signs of stress in a number of ways.
The problem though is that stress is often a consequence of multiple factors so it can be tricky not only to identify the problem but to fix it as well.
Nonetheless, the easiest way to identify whether or not your pets are stressed is by looking at their activity, appetite, and appearance.
If shrimp zoom around in the tank or barely move, if they seem to be less hungry than normal, or their color fades – it is extremely likely that there may be something wrong.
Other changes are not that obvious, especially for beginners, and include decreased growth, molting problems, reduced fertilization success, decreased fecundity, and loss of eggs.
As we can see, stress can cause legitimate and very devastating health problems for your shrimp. Thus, the causes of stress should be attended immediately.