Pistol Shrimps: Everything you need to know about this Amazing

Most people are afraid of weapons, because these are usually dangerous  and lethal . But what would happen if you suddenly  find a Pistol Shrimps, who has his own deadly weapon.


This is a kind of shrimp just like the others, but he has a small and sonorous difference, his deadly weapon, a powerful claw that emits a sound like a shot.

Characteristics of Pistol Shrimps

This is the common name of these crustaceans. They  belong to the family Alpheidae, and they are the only specimens, that can generate such a powerful snap. The Pistol Shrimp is a decapod crustacean, like most of this species.

Pistol Shrimps

Generally, these shrimps have a dark brown body, or brown green, with a large amount of rounded small spots in pale  green ,  even yellowish;  which form transversal bands. They can also be wholly white.

This species of shrimps is characterized by the excessive growth of  one of its claws or periropods, which makes these appendages asymmetrics . This is the reason why this small crustacean receives his name, since this claw or pincer generates  a short transient acoustic signal when it closes.

This pincer produces a very strong shock wave,   that is able to compress the water bubbles, that now  are directed to the prey,  which  can die immediately, or be stunned so that the shrimp will continue his  attack.

Pistol Shrimps  like all the others shrimps are invertebrates, and they are  also very small, because they grow to only five centimeters in length. They usually live in big colonies located inside caves

According to the scientists, the snap of the pincer is only employed for offensive and defensive purposes, because just as it is used to hunt, he also does so to defend himself against a possible rival or predator. This snap produces a jet of water that can scare anyone who gets too close.

The researchers also assert that the biological meaning of the sound produced by this click or snap , plays a very important communicative role.

How does the Snap Sound?

This peculiar characteristic of Pistol Shrimps  was already known by scientists, who had studied the crustacean for a long time. However, it was not until 1942 that the mystery of the loud noise produce d by the Pistol Shrimps  with their  pincers  was revealed.

To get the final conclusion , several laboratory tests were developed to different specimens, in different fields of study, and different populations from different habitats;  in order to know the truth, since in 1887 the sound was mistakenly attributed to the opening of the dactyl.

Since that time, many researches have been performed in different parts of the world, describing  the sound of the clicking as one of the most pervasive sources of underwater noise.

Given the power of the sound produced by the Pistol Shrimp, none other sound exceeds it in importance, since it is believed that it can even interfere with the measurement and recording of Bio Acoustic signals that submarines make in shallow waters.

In this video you will hear the sound produced by the  snap of the claw of a pistol shrimp in a fish tank.

The physical phenomenon produced when the pincer closes, is  known as cavitation, and it is a sound that reaches according to the experts, the two hundred and eighteen decibels. This snap is so fast that it produces a jet of water that shoots out more than one hundred (100) kilometers per hour.

This movement is so fast that pulverizes  the water,  making a bubble that reaches  five thousand (5000)0 kelvins, (according to scientists,), which is the  temperature at  the surface of the Sun,  and it is very difficult to perceive at first sight, since it only lasts one millisecond.

Pistol Shrimp Close Up


An expansive wave is produced and depending on the size of the victim it can be stunned  or killed  . Therefore, the shot doesn’t  come directly from the claw, but from the hot energy of the bubble. This is in itself cavitation, when the water is forced to move.

This sound can be emitted  by the shrimp with a simple snap and when it occurs in a population or colony of these crustaceans, it turns out to be a continuous high crunch. The noise produced by these shrimps is highly penetrating, although it usually varies during the day.


It is believed that the constant crunch of the shrimps colony     is so powerful, that  it could  be heard on the surface of the water  if it were quiet ,. This is due to the fact that the closing of the claw produces an acoustic signal with a very wide bandwidth, with components over two hundred KH.

This theory was recently discovered, thanks to the use of a system that allows recording at high speed, and another one of acoustic detection, which provides tools  for  studying  the behavior of this species in its natural habitat.

In this video you can watch how the Snap of the Pistol shrimp occurs.

Habitat and Distribution of  Pistol Shrimps

Shrimps in general, live in all the  waters of the world, either freshwater or in the  sea, and the Pistol Shrimps are not  the exception, so you can find these small crustaceans around the globe.

These creatures are benthic, which means they spend their lives in the depths of the ocean, but sometimes, they also develop other behaviors and could even live at different water levels.

For example Pistol Shrimps can be found on coral rocky bottoms, as well as  coral reefs, coral reef cavities, debris, and coral cracks. Although it`s not very common Pistol Shrimps can even live on sponges, bryozoan, and intertidal reefs of sabellid polychaetes.

Pistol Shrimps  are distributed throughout the American Continent, specially  in Florida and the Gulf of Mexico; likewise, as they feel very comfortable in the warmer waters, they are also present throughout the Caribbean Sea,  mainly in Brazil.

Learning How these  Shrimps  live in  Fish Tanks

Pistol Shrimps group  in pairs  , making  a cave where they can live. Since they really like corals, it is recommended to place one of these, or a similar structure, so they could feel comfortable.

You must also have enough sand so that shrimps  can dig, since their hobby is to make caves, which they always try to keep neat.

Although the Pistol Shrimps  are extremely small, you must take into account the size of the aquarium where they will live, and the number of specimens that will be introduced into it.

These crustaceans are usually very temperamental, especially males, so enough space is required  for everyone to cohabit in peace. In the same way you should keep in mind what kind of animals are going to share this ecosystem with the shrimps, because as we already know, these creatures have  a powerful weapon that can easily break  the shells of other shrimps . They  could even break the glass of your Fish Tank, if it is not strong enough.

Pistol Shrimps’ Behavior

Some scientists have labeled these shrimps as crazy, and it is because of their temperamental nature, ; it’s the same for them to attack a puffer fish, or break the shell of an unsuspecting crab. They  seem  more like quarrelsome  than  gentle sea shrimps.

In general, males of all species always have the largest chubs , talons, and teeth, and the largest and heaviest bodies. It is very common also that these males are more aggressive than females. In the Pistol Shrimps species, there is not much difference.

Males  Pistol Shrimps are much more aggressive than females, which is the reason  why  they have their tongs torn, in comparison with  those of females.  According to different   studies that have been performed the bigger the male’s pincer, the more aggressive his behavior is.

Pistol Shrimps in couple

The males of this species are more tolerant among each other,  they even prefer to share their caves, before facing with one of them. This is the reason why they can live in colonies  of Pistol Shrimps, within  a reduced space.

But when it comes to another species, the Pistol shrimps  don’t  have any considerations or contemplation, so they are willing to use their best weapon to attack them without mercy.

But females  Pistol Shrimps are not left behind, although they are less aggressive than males, they also fight bloody battles to defend their territory. Unlike the males, the females only tend to fight with the females, always avoiding a confrontation with the males of their species.

Shrimps Pistol in their Caves

Since  this  species was recently discovered , there are still many unknown  aspects about Pistol Shrimps. For example there isn’t yet a certain explanation, about why females behave more aggressive among them, than against females of other species.

There is a theory about this; since males tend to share their caves with other males, thus females don’t   fight for territory , but for partner.  It is quite possible that they prefer to have more males, and not to share them with the other females.

So they are not aggressive with the females of other species, since these even become in the food  of their partners . So then, this could  be a bout of gender, in order not to share the males, and have a better chance for reproducing

In spite this behavior, they can also share their caves with a partner, and with other fish. This is almost a business, because the shrimp is responsible of  cleaning chores  while the fish guarantees the safety they need.

Watch  the behavior of the Pistol Shrimps  in this video.

How do Pistol Shrimps Hunt

These  shrimps  have  a very peculiar way of hunting, since they are conscious of the powerful weapon they have, which is extremely effective, and helps them get their food successfully.  This is why these creatures remain hidden or entrenched in their caves , waiting for a potential prey to pass close to  them.

Once  they visualize  their  prey , they  load their pincer as if it were  a magnum of high caliber, and then when the victim is close,  the weapon produces the click that emits the bubble of water which hits it strongly.


In some cases, the impact is so strong that it kills the victim immediately,  and some other times, the impact only stuns it , so that the Pistol Shrimp has the opportunity to attack it and finish his job.

Sometimes this depends on the size of the prey, and how accurate the blow can be, since occasionally, the victim can face his attacker, and fight. Even sometimes, the Pistol shrimp loses  one of his   pincers, so his  has  to abandon the fight.

Although this is not a serious problem for these  crustacean, because when they lose  the main pincer, the remaining pincer grows becoming the main one . The  pincer that was lost also regenerates, but this time it will be the second pincer,   and the process starts once again.

That is why you can see specimens with the largest pliers both in the left clamp, as in the right clamp.

Reproduction of Pistol Shrimps

The exact moment for the reproduction of the Pistol Shrimps, is just after  the moult of  the female’s  exoskeleton, because it is in  this right  moment, when her skin is as soft as needed  . In some species, the male looks for the female that is about to change her exoskeleton, and waits for her, but in the case of the Pistol shrimps, they live as a couple in the same cave, so the male only has to wait for her to be ready to mate, and while she has her  body susceptible to predators,  he is the one  who protects her.

Once the female is ready for mating, they  interweave  and the copulation can last several seconds. After having copulated, the shrimps remain together for hours, and sometimes they can even spend days together swimming in the same way.

Shrimp Copulating

As we mentioned before, the study of this species started  a short time ago,   so  we don’t  have enough  details about this process; even males have been observed who don´t  consider it necessary to wait for the female to moult her exoskeleton for mating, and  they try to interact with several females, because they don’t  have a partner in the cave..

In this case, it seems to be casual sex, because once they have copulated, they both separate and don’t  swim together, as  the couples  who live together do. This behavior is being studied.

But it can also be similar to a non-consensual sex, since in  many occasions the females are victims of the violent nature of the male,  and they usually lose one or more of their appendages, during the fight and copulation.

During the copulation the female Pistol Shrimp,  produces a gelatinous mass between her  fourth pair of legs, and the male deposits the sperm in  it. After this process the female can put,  up to fifteen thousand (15.000) eggs to be fertilized by the sperm in the breeding chamber that is at the bottom of her tail.

In other species, the female only disperses the eggs in the water, where they will develop on their own.

In this video you can  watch  the mating process of these  Shrimps.


Offspring Developing

The offspring (floating larvae  when just born )  leave from the eggs , and they go through a series of changes as they grow. Before developing  an adult body, the larvae will moult it’s skin several times. This process can last between one and four months, then they will have already developed as adults, and will be sexually mature to reproduce.

The Pistol Shrimps and the Human Beings

Shrimps   are a paramount piece   of the food chain in their natural habitats,   since they feed on a wide diversity of microorganisms and remains of former marine life at the bottom of the sea. But shrimps are also the source of food for many other animals that are pleased to have them in their menus .

Just as these animals are pleased with the presence of shrimps in their food,  humans are also commonly delighted  about having shrimps in their   basic diet. And this is not only due to the pleasant taste of their meat, but also to the benefits that these animals bring to the health of people with every one of their properties.

Shrimps  Trawling

We  have to start mentioning the  big amount of jobs generated by shrimps fishing , which are  present in all the waters of the world, they are known and valued worldwide, this  is why it is necessary to keep them in all markets, and this generates employment for many fishermen who work in fishing boats, and also for  independent fishermen.

When people carry out this  fishing,  they are not looking for an  specific  kind of shrimps; in fact a wide  variety of species are caught in the fishing nets, including the Pistol Shrimps.

Packaging of Shrimps for Export

In addition to the employment generated by fishing shrimps  in the sea, they are also grown on land, so this is also a source of employment for people working in these places, who are responsible  of taking care of these creatures, in order to guarantee their proper and healthy lives as well as their reproduction. Then we also have  the packaging and distribution processes, which represent  a hard work that has to be done, in order to distribute this delicious food to different places.

But aquaculture has many detractors, because they consider that shrimps do not live in freedom, but rather crowded together  and prepared for certain death, because they are cultivated for this sole purpose. And also because these hatcheries  are regularly located in the most oppressed sectors of developing countries, causing people exploitation, who perform long hours of work, for a very low salary.

Benefits of Shrimps

Shrimps have a large number of properties that make of these  crustacean  a must have  in people’s diet, since they bring a variety of benefits for health, that few other foods possess.

One of the best-known components of this food, is vitamin B12, which is one of the responsible for the proper functioning of the body. And  when people are sick, vitamin B12  is quite useful  for restoring health . For this reason, many people prefer to eat a good recipe of shrimps when they feel sick.

This is also an excellent food that should be included in the diet of pregnant women because it  gives them a high content of folic acid that is necessary for the development of the fetus when he  begins to grow in his initial stage.

But this food not only favors the pregnant women, but also men who want to have family, because shrimp is not only an effective aphrodisiac for humans, but also stimulates the production of healthy and competitive sperm.

The reduction of chances  of suffering coronary or cardiovascular disease, is another benefit of including shrimps in our diet.  In the same way, shrimps  are an indispensable  element for people who have any type of nervous imbalance.

    • Losing  Weight

Although there is  a huge controversy regarding the level of cholesterol that shrimps may have, it has been scientifically proven that an egg has much more cholesterol than a quarter of a kilogram  of boiled shrimp.

This is the reason why they represent an ideal food for people who want to lose weight, not only because they

Contain  few calories, but because they  are rich in proteins, and this is an excellent combination to burn fat and provide the energy that is required when  exercising

Another benefit of this food is that it keeps the skin hydrated, which prevents the formation of wrinkles. Since  shrimps also contain  vitamin E they provide the skin with the elasticity it needs, and in addition, it prevents atherosclerosis, because it prevents the arteries from becoming clogged.

Senior couple

Eating shrimp is very beneficial, because it prevents the formation of blood clots, and thanks to the presence of selenium among its properties, not only protects the immune system, but also the cardiovascular system. For this reason, shrimp should not be missing from the basic diet of people who are already elderly.

How to prepare Shrimps

In the same way that there are so many species of shrimps, there are also different ways to prepare this delicious food, which for some people is a delicacy. Although there have been some controversies about the shrimp shell, whether it is swallowed or not, it depends on the taste of the people.

There are people who like to eat raw shrimps, and nothing happens; and there are other people who prefer to wait until shrimps go through water and salt.

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