Can a Mantis Shrimp Kill a Human?

Mantis shrimp also known as thumb splitters, are marine crustaceans that pack a mean punch with their raptorial claws. They have even been called the “boxing champions of the sea”. But could their powerful strikes actually kill a human being?

  • Mantis shrimp belong to the order Stomatopoda and get their name from their raptorial front claws which they use to strike prey in a “praying mantis-like” fashion.
  • There are over 500 species worldwide in tropical and subtropical waters.
  • They are divided into “spearers” which impale prey with spiny appendages and “smashers” which pound prey with club-like claws.

Smashers in particular have become famous for having one of the fastest and most powerful punches in the animal kingdom. Using a spring-loaded mechanism, they can strike with the acceleration of a .22 caliber bullet. Their blows deliver an impact of over 1500 Newtons with speeds exceeding 50 mph underwater. This allows them to easily break open hard shells of mollusks and crustaceans.

Documented Mantis Shrimp Injuries to Humans

Mantis shrimp are notorious for inflicting painful injuries when handled Here are some documented cases

  • Lacerations and bleeding wounds from their sharp, serrated claws. In one case, a deep cut caused an ulcer on a student’s hand that took weeks to heal.

  • Fractured bones in fingers from the high-speed blunt force trauma of a smasher’s strike, One fisherman suffered severe pain for an hour after being hit in two fingers,

  • Puncture wounds from the sharp tail spikes that can also draw blood. A fisherman trying to unhook a mantis shrimp was jabbed in the ankle leaving a lasting scar.

  • Persistent unhealed wounds that last for weeks or months if not properly treated with antibiotics and cleaning.

So mantis shrimp claws can certainly inflict very painful and dangerous injuries on humans. But could the blow be deadly?

Factors That Reduce Lethality Against Humans

Despite their fearsome reputation, there are several reasons a mantis shrimp is unlikely to kill a person:

  • Smaller Size: The largest mantis shrimp grow to about 12-15 inches long. Many are just a few inches long. Their claws have less mass and striking force than required to fatally wound a human.

  • Strike Accuracy: Mantis shrimp mainly strike prey directly in front of burrows. It would be difficult to precisely hit a vulnerable spot on a human.

  • Situational Factors: Humans do not provide an ideal striking surface like a hard mollusk shell and humans would instinctively recoil from a blow.

  • Shorter Strikes Out of Water: When removed from the water, the strikes of a mantis shrimp lose speed and impact. Their blows become far less dangerous.

  • No Confirmed Deaths: Despite many mantis shrimp injuries over decades, there are no scientific reports of human fatalities. If their strikes were lethal, human deaths would be documented.

So while mantis shrimp can certainly inflict very painful injuries, there is no evidence that their strikes could generate enough force to kill a human being. Their small size, situational factors, and lack of documented fatalities strongly suggest their strikes are not powerful enough to cause human death.

First Aid for Mantis Shrimp Injuries

If you are unlucky enough to be struck and injured by a mantis shrimp, here are some first aid tips:

  • Immediately wash the wound with soap and water to reduce risk of infection.
  • Apply pressure to stop any bleeding.
  • Disinfect and bandage the injury.
  • Take over-the-counter pain medication for pain relief.
  • Seek medical care for severe cuts, bleeding, or persistent pain.
  • Get a tetanus shot if your last shot was over 5 years ago.
  • Take prescribed antibiotics to prevent wound infections.

Avoiding Mantis Shrimp Injuries

While mantis shrimp are fascinating animals, it’s best to admire them from a safe distance to avoid injuries:

  • Leave them undisturbed in the wild and don’t handle them.
  • Carefully remove them from fishing nets using gloves and gripping their abdomen.
  • Wear protective footwear when wading in mantis shrimp waters.
  • Supervise children playing in mantis shrimp pools at low tide.
  • Release captive mantis shrimp if keeping them legally.

So show caution and respect for these small but mighty marine creatures! While they can certainly pack a punch, mantis shrimp do not pose a lethal threat to humans. With proper first aid and some common sense precautions, we can safely coexist with these remarkable little boxers of the sea.

can a mantis shrimp kill a human

Antonio Lucas Sforcin Amaral

1 Universidade Estadual Paulista, Instituto de Biociências de Botucatu, Departamento de Zoologia, Botucatu, SP, Brasil. Find articles by

1 Universidade Estadual Paulista, Instituto de Biociências de Botucatu, Departamento de Zoologia, Botucatu, SP, Brasil. Find articles by

2 Universidade Estadual Paulista, Faculdade de Medicina de Botucatu, Departamento de Dermatologia e Radioterapia, Botucatu, SP, Brasil. Find articles by.

ALSA came up with the idea for the study, interviewed people, talked about the results, wrote the manuscript, and drafted the article. ALC oversaw the project and manuscript writing and gave final approval to the version that would be sent in. VHJ came up with the idea for the study and the structure of the manuscript, interviewed people, oversaw the project and the results of this study, talked about the final manuscript, and gave final approval to the version that would be sent in.

Mantis shrimps or siriboias are crustaceans belonging to the order Stomatopoda. They are known for their strong claws, which they use for defense and capturing their prey. They are split into two groups: the spearers, who pierce their prey with sharp projectiles, and the smashers, who hit their prey hard with powerful punches. Fishing people are very afraid of these animals, and there are many reports of people getting hurt by these crustaceans.

Twenty-three fishermen from Colony Z10 in Ubatuba, São Paulo state, Brazil were given a questionnaire about injuries to humans caused by these stomatopods. The literature on injuries to humans caused by these animals was also looked at.

The fishermen think that the mantis shrimp are dangerous and stay away from them because of that risk. We talk about five reports of people being hurt by these animals: four by their claws and one by their tail spikes.

We talk about first aid, how to avoid these situations, and what to do in them. We also suggest that educational leaflets be sent to the fishermen colonies.

Mantis shrimp are marine crustaceans that belong to the order Stomatopoda Latreille, 1817. They are also called siriboia, tamarutaca, tamburutaca, boxing shrimp, or squilla. “Siriboia” is an indigenous word formed by joining the words “si’ri” (crab) and “mboi” (snake/serpent) 1 . They are called “mantis shrimp” because their claws are raptorial and they attack their prey like a mantis (Insecta: Mantodea), which strikes with its forelegs. Mantis shrimps have a global distribution and occur in tropical and subtropical waters 2 , 3 , 4 . There are 43 species in Brazil, spread out along the coast from Amapá state (latitude 03º north) to Rio Grande do Sul state (latitude 30º south) [5, 6, 7, 8]. They belong to 10 families.

These animals are unique because they can attack prey with their second thoracic legs, which have been changed into raptorial claws (A and B) 9. Mantis shrimp are split into two groups based on the shape of their claws. The claws of each group do different things. The first group, called spearers, has claws with three to eleven spear-like projections that open when they get close to their prey and close when they reach it. So, they catch their prey and spear it with their claws, which pierce the prey’s body and stop it from running away (B, C, and E) 5–11 These animals can strike at speeds reaching 6 m/s (approximately 21 km/h) 12 . They usually occupy burrows in sandy sediments 13 , 14 .

The second group, called smashers (F), is made up of species whose claws have a big, hardened bump at the base that they use to hit their prey at speeds of up to 30 mph. six meters per second (108 kilometers per hour) and an impact force of 1500 Newtons (152 kg), which is the same speed as a 9mm pistol bullet 9, 15, 16, 17 These animals inhabit burrows in rocks and corals 12 , 13 , 14 , 18 .

Along with their claws, these stomatopods have two uropods, which are parts of the tail that make up the “caudal fan” (C). The uropods each have two sharp spikes on them (D) that can be used as weapons.

The fishermen are afraid of the “siriboia” when they are in their nets or walking in the water at low tide. The stomatopods are known as “thumb splitter shrimp” in some parts of the Caribbean, which shows how dangerous they are 19–20. These animals are difficult to observe. Further, the information on the injuries they cause to fishermen is limited 21 . Therefore, we aimed to identify and describe:

  • Injuries that have already been written about or from unpublished data collected by experts on marine animal injuries
  • An interview process was used to find out how often injuries happened in the fishermen’s colony Z10 in Ubatuba, São Paulo, Brazil.

A literature search was done to find reports of mantis shrimp injuries to humans that were written by health and/or zoological professionals who have worked in fishermen’s colonies. The reports were looked at to find out what happened and how the wound looked so that researchers could figure out how the injuries happen and what effects they can have.

It included peer-reviewed journal articles and notes that talked about stomatopods and how they interact with fishermen. It also included books about the topic written by researchers who have studied injuries caused by marine animals.

The municipality of Ubatuba is in the southeast of Brazil, on the north coast of São Paulo state (23°26′2′′ South, 45°5′9′′ West). It is in an area with open seas and estuaries 22 It was easier to get in touch with the fishermen in Ubatuba’s Z10 fishermen’s colony, which is why a stratified questionnaire was given there. Workers who were in the colony at the time of the interview were asked to answer the questions after giving their permission and confirming that they were fishermen who worked in the colony. Those who did not work as fishermen in the colony were excluded. The fishermen who met the same criteria as indicated by the interviewees were also interviewed.

Along with pictures of the animals to help with identification, the interviewer gave out a questionnaire that asked about the injuries caused by the stomatopods. The questions asked were as follows:

  • Have you heard of siriboias/tamburutacas?
  • Are siriboias/tamburutacas dangerous?
  • Did you suffer from injuries due to siriboias/tamburutacas?
  • If yes, how and where did it happen?
  • Do you have any sequelae due to the injury?
  • Do you know anyone who has been hurt by siriboias or tamburutacas?

The answers obtained were recorded through handwritten notes and counted at the end of the interviews. Even information that wasn’t directly related to the applied question was written down if it showed important facts about how the stomatopods and humans interacted. The results were improved by including descriptions of four cases of stomatopods hurting people that the authors had seen happen on other occasions. These cases add to the reliability of the fishermen’s answers to the questionnaire.

The authors were given permission by the Ethics Committee in Human Experimentation of Faculdade de Medicina de Botucatu, São Paulo State University, to study fishermen from the Fish Market of Ubatuba and the village of Picinguaba. Their registration number is CAAI 59887316. 5. 0000. 5411, report number 1. 759. 505 and by the Healthcare Department of Ubatuba, São Paulo.

All the 23 fishermen who were interviewed reported knowing the stomatopods. Also, everyone who was interviewed said they thought these animals were dangerous, even though none of them had been hurt or had any problems afterward. However, five fishermen (21. 7%) reported knowing people who had been injured by these crustaceans. In one of these cases, a fisherman around 50 years old used a fishing rod to catch a stomatopod from a sandy bottom (E). So he wouldn’t hurt himself, he held the animal by the claws as he tried to get it off the hook. However, it hit him in the hand with its tail, which made holes in the tail spikes that caused pain and bleeding. One of the interviewees said that the smaller specimens can be moved around by folding their abdomen in half so that the claws and uropod are touching. This makes it impossible for the specimens to hurt the hands.

Four reports of stomatopods hurting people have been written and seen in other places (20, 23). These reports show that fishermen should be careful around these animals.

Case 1: A 24-year-old fisherman was hurt while working with a fishing net in Salinópolis, Pará state, Brazil. The net was in a “curral,” which is a structure made of wood that traps fish and makes them easy to catch. He wasn’t paying attention to the stomatopod in the net when it hit him in the hand with its claws, damaging tissue and causing severe pain that lasted for about an hour. It hit him on the fifth left finger and the second right finger. He said he washed the area very well with soap and water, and in about a week, it was completely healed.

Case 2: The stomatopods hurt a 54-year-old fisherman three times on his hands while he was fishing for shrimp in Ubatuba, São Paulo state, Brazil. He said that the animal was easy to find in the fishing nets and that two injuries on his fingers had left scars on them (A). Besides that, he said he didn’t get any treatment for the wounds when they happened, and they didn’t heal for weeks 23.

Case 3: A 22-year-old fisherman in Ubatuba, São Paulo state, Brazil was hurt by a stomatopod while getting off the boat with a net full of fish. He stepped on something and felt intense pain in the medial malleolus of his right foot. Although he was unable to catch it, he said he saw the stomatopod because the water was clear there. The area bled heavily, and the wound persisted for months ( B). At the time of recording the interview, there was an extensive scar in the area 20 .

This case is about a 25-year-old biology student in Ubatuba, São Paulo state, Brazil. He hurt his left hand with a stomatopod while working with a specimen in the field (C). The claws cut deeply and caused a lot of bleeding, which led to an ulcer that healed in about three weeks. The animal was not collected for subsequent identification.

The interviews we conducted indicate that fishermen know how these crustaceans cause injuries. They stated that the claw is dangerous, and caution is necessary to avoid getting hurt. The findings showed that the stomatopods can hurt people when they are handled in fishing nets or rods, when they are stepped on in the sand, or when they are caught by hand. The spearers’ and smashers’ claws are very well shaped for catching prey, and they can hurt people.

The injury shown in C shows that these animals are very strong and fast. There is tissue loss in the area, but it is not possible to say for sure whether the wound was caused by a spearer or a smasher. In B, the wound looks deeper and has a round shape, which means it was hit with a lot of force. This suggests that it was likely caused by a specimen with smasher claws.

We got information about the injuries that was put together in a chart so that health professionals and researchers could easily read it.

There are no guidelines on prevention of injuries caused by the stomatopods, possibly because such incidents rarely occur. Based on the information we gathered for this study, we suggest the following way to treat stomatopod-related injuries:

When a MANTIS SHRIMP PUNCHES A HUMAN(it forking hurts!)

Are mantis shrimp dangerous?

The fishermen consider the mantis shrimp dangerous and avoid direct contact with them on account of the associated risk. We describe five reports of human injuries caused by these animals: four by the claws and one by the tail spikes.

Can a mantis shrimp punch a person?

A mantis shrimp’s powerful punch can hurt humans. A shrimp can land before a person even realizes it is there because its strike is so quick. Shrimp punches cause deep wounds and lacerations with rounded edges. There is almost always a loss of tissue after a mantis strike and heavy bleeding.

What happens if a mantis shrimp hits a fish?

The shrimp’s punches leave deep wounds and lacerations with rounded shapes. After a mantis strike there is almost always a loss of local tissue along with heavy bleeding. Fishermen attacked by mantis shrimp say that it hurts terribly to get punched or pierced by them.

How do mantis shrimp kill worms?

1. All mantis shrimp species can be divided into ‘spearers’ or ‘smashers’, based on the types of claws they have and tactics they use to kill the prey. Spearers have spiny appendages with barbed tips, that are used to stab soft-bodied prey, such as different types of worms and fish.

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