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Mastigoproctus giganteus

What do they look like?

Giant vinegaroons look like scorpions in many ways, but are actually more closely related to spiders. Their pedipalps are modified into two large claws. They also have two front legs that are held above the ground, and six legs that are used for walking. They have a thin, flexible tail at the end of their abdomen, which gives them the common name 'whip scorpions', as the tail looks like a whip. The body is divided into two parts, the front cephalothorax (prosoma) and the abdomen (opithosoma). Both sections are flat and oval-shaped. There is one pair of eyes located on the front of their head, while there are 3 more eyes on each side of their head. Giant vinegaroons are one of the largest species of vinegaroons, growing to lengths of 40 to 60 mm, not including their tail. Their body is typically black, with some brown or reddish-brown sections or appendages. Males have larger claws than females. Nymphs look like adults, though they lack a few small characteristics. (Hembree, 2013; Punzo, 2005; Schmerge, et al., 2013; Weygoldt, 1970; Weygoldt, 1971)

  • Range length
    40 to 60 mm
    1.57 to 2.36 in

Where do they live?

Giant vinegaroons or giant whip scorpions (Mastigoproctus giganteus) are native to the Nearctic region. They are found in the southwestern United States, including New Mexico, Arizona, Texas, and areas just to the north. They also live in much of Mexico, and are also found in Florida. (Carrel and Britt, 2009; Punzo, 2005; Punzo, 2006)

What kind of habitat do they need?

Giant vinegaroons typically live in dry desert habitats in the southwest, and scrub forests and grasslands in Florida. They have also been found in dry mountainous areas, as high as about 6,000 m. They can be found taking shelter beneath plant debris, in rock crevices, or in burrows dug by other animals or themselves. (Eisner, et al., 1961; Hembree, 2013; Kern Jr. and Mitchell, 2011; Punzo, 2005; Punzo, 2006)

  • Range elevation
    6000 (high) m
    19685.04 (high) ft

How do they grow?

Giant vinegaroons go through incomplete metamorphosis, with egg, nymph, and adult life stages. Once the eggs hatch, the nymphs climb aboard the back of the female, and remain there for about a month, until their first molt. After their first molt, the nymphs leave their mother. Giant vinegaroons have 4 nymphal stages, with a molt in between each stage where they shed their skin, before reaching adulthood. Molts occur about once a year, usually during the summer. Preparing to molt can take months, during which, the vinegaroon constructs a molting chamber that it does not leave, not even to feed. The abdomen inflates, until the skin splits, and the newly molted nymph emerges from the skin. The new nymph is white, and stays white for 2 or 3 days. It takes about 3 to 4 weeks before the color completely changes to black. During this time, their skin also hardens. After the fourth and final molt, the adult is now able to mate. (Weygoldt, 1970; Weygoldt, 1971)

How do they reproduce?

Mating typically takes place at night, during the fall season for giant vinegaroons. Before mating begins, fights often break out between males and females when the female does not want to mate. If the female does want to mate, she approaches the male, and the male then grabs her first pair of legs with his claws and mouthparts. Holding on to the female, the male moves backwards, dragging the female with him. He strokes her, and the female moves backwards. The male follows her for a few steps, before he moves backwards, pulling her with him again. This back and forth "dance" can go on for several hours. Eventually, the male releases the female and turns so that they are facing the same direction. He produces a spermatophore, which holds the sperm, and places it on the ground. He pulls the female over it, and her genitals pick the sperm up. The male turns around and uses his palps to move around the sperm carrier and the female's genitals, making sure the sperm gets inside. This goes on for 2 or more hours, until they finally separate. (Kern Jr. and Mitchell, 2011; Weygoldt, 1970)

After mating, females carry the fertilized eggs inside of them for a few months. They then lay the eggs in a fluid filled sac that is protected from drying out, with each sac holding 30 to 40 eggs. The sac is carried by the female, held from underneath her abdomen. Females stay in their burrow during this process for an additional two months, without moving and holding the egg sac off the ground while the eggs develop. Finally, the eggs hatch and the nymphs climb aboard the female's back, staying about a month until their first molt, after which they leave. By this time, the female is usually so weak and starved from not feeding that she eventually dies. Because of this, females only produce one egg sac in their lives. Giant vinegaroons are ready to mate 3 to 4 years after hatching. (Cloudsley-Thompson, 1968; Hembree, 2013; Kern Jr. and Mitchell, 2011)

  • How often does reproduction occur?
    Females breed only once during their lives.
  • Breeding season
    Giant vinegaroons mate in the fall.
  • Range number of offspring
    30 to 40
  • Average time to independence
    1 months
  • Range age at sexual or reproductive maturity (female)
    3 to 4 years
  • Range age at sexual or reproductive maturity (male)
    3 to 4 years

Female giant vinegaroons provide significant care for their offspring. The eggs are laid in an egg sac that females carry from their abdomen for two months. After the eggs hatch, the nymphs cling to their mother's back and stay there until their first molt. During this time, the female does not leave her burrow, and becomes very weak as she does not feed. She provides so much care and protection for her young that she does not take care of herself, and by the time the nymphs leave, she is so starved that she dies shortly after. (Cloudsley-Thompson, 1968; Kern Jr. and Mitchell, 2011; Punzo, 2005)

  • Parental Investment
  • female parental care
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • protecting
      • female

How long do they live?

Giant vinegaroons usually live 4 to 7 years, though some individuals have been known to live even longer. (Hembree, 2013)

  • Typical lifespan
    Status: wild
    4 to 7+ years

How do they behave?

Giant vinegaroons are nocturnal, hunting during the night and taking shelter during the daylight, when temperatures are warm. Adults are usually solitary, staying in their burrows or shelters alone. While some take shelter between rocks or under debris, many giant vinegaroons dig their own burrows. They use their large claws to dig, and carry the extra dirt away from the burrow to one pile that they use throughout the digging process. Some burrows are temporary, while others are used for several months. They will also fix the burrows and add tunnels and chambers, though they do very few activities within the burrows. Giant vinegaroons often sit motionless in their burrow, and their tunnels and chambers are only big enough for them to turn around. Sometimes prey will fall inside the burrow opening, giving them an easy meal. Vinegaroons are said to be able to run very quickly, particularly when chasing prey. However, giant vinegaroons are more likely to walk around slowly and cautiously, using their antenniform legs to feel the ground as they walk. Giant vinegaroons may act very aggressive towards each other, with violent fights that often end in severe injuries or death. Larger females have also been seen cannibalizing smaller females. When threatened by predators or other vinegaroons, giant vinegaroons take up a defensive posture by raising their abdomen and claws, and sticking their stiff tail straight out. (Cloudsley-Thompson, 1968; Eisner, et al., 1961; Hembree, 2013; Punzo, 2005; Punzo, 2006; Weygoldt, 1970)

Home Range

Adults may stay in the same burrow for months, though at other times they may stay in a burrow for only a day or two. Their home range extends as far as they can walk, though they likely stay in the same general area. (Hembree, 2013)

How do they communicate with each other?

Giant vinegaroons walk on their back 3 pairs of legs, and use their first pair of legs as sensory organs. The first pair of legs, often referred to as antenniform legs, since they act like another pair of antennae, are held off the ground, and have receptors on them that can detect chemicals. They also use the first pair of legs to feel their surrounding area, tapping the legs over the ground and other objects as they move along. They use these legs to find prey and mates. Having a strong sense of touch is important since they are nocturnal, and do not have strong vision during the day or night. The antenniform legs can also be used to find water sources, such as wet sand. Their tail and claws are also used as sensory organs. The 6 legs used for walking are covered in sensory hairs. Touch is also important during mating, since the male holds onto the female throughout the mating process. (Cloudsley-Thompson, 1968; Crawford and Cloudsle, 1971; Kern Jr. and Mitchell, 2011; Punzo, 2006; Schmerge, et al., 2013; Weygoldt, 1970)

What do they eat?

Giant vinegaroons are carnivores. They are predators that feed on a variety of Arthropods, primarily insects such as cockroaches and crickets, as well as millipedes, and other arachnids. They have even been seen feeding on small frogs and toads. They use their large claws to hold prey, while their mouthparts tear and bite the prey. (Carrel and Britt, 2009; Cloudsley-Thompson, 1968; Punzo, 2006; Schmerge, et al., 2013)

  • Animal Foods
  • amphibians
  • insects
  • terrestrial non-insect arthropods

What eats them and how do they avoid being eaten?

To defend themselves from predators, giant vinegaroons can spray a vinegar-like substance from a gland at the end of their body by the base of their tail. This vinegar spray is why they are called 'vinegaroons'. The spray is very effective at keeping predators away. Since giant vinegaroons only spray when they are physically poked or prodded, the predators are usually very close when they get sprayed, often in the face. Vinegaroons are also very accurate with their aim. When a predator gets sprayed, they are often seen darting away, shaking their head and trying to clean themselves, clearly bothered by the spray. After that, they usually think twice before trying to eat another vinegaroon. Giant vinegaroons can spray up to 19 times within a short period of time, and once they are out, they can spray again by the next day. Some small mammals, such as grasshopper mice, deer mice, and shrews, can successfully eat giant vinegaroons, despite the vinegar spray. These small animals are often very aggressive and attack the vinegaroon over and over again, until they run out of spray. Camel spiders are also predators. Larger mammals such as raccoons, armadillos, and feral hogs are also likely predators. (Eisner, et al., 1961; Punzo, 2006; Schmerge, et al., 2013)

What roles do they have in the ecosystem?

Giant vinegaroons are significant predators of many insects and other arthropods. They are also occasionally eaten by small mammals such as deer mice and shrews, as well as larger mammals such as raccoons and wild hogs. (Eisner, et al., 1961; Punzo, 2006; Schmerge, et al., 2013)

Do they cause problems?

Giant vinegaroons spray a substance that smells like vinegar from a gland by their tail when they feel threatened by a predator or by a human. This spray can cause irritation and pain, especially if it gets in the eyes. In at least one case, the spray caused a person's skin to blister. Giant vinegaroons can also pinch with their large claws. (Eisner, et al., 1961; Kern Jr. and Mitchell, 2011)

  • Ways that these animals might be a problem for humans
  • injures humans

How do they interact with us?

Giant vinegaroons can be kept as pets, similar to scorpions and tarantulas. They can be kept in aquariums, and are fed insects such as crickets. They can be handled with care. (Backwater Reptiles, 2011)

  • Ways that people benefit from these animals:
  • pet trade

Are they endangered?

Giant vinegaroons are not an endangered species.

Some more information...

Giant vinegaroons are also called "grampus" in some regions. (Cloudsley-Thompson, 1968)


Angela Miner (author), Animal Diversity Web Staff, Leila Siciliano Martina (editor), Animal Diversity Web Staff.


Backwater Reptiles, 2011. "Whip Scorpions for Sale" (On-line). Backwater Reptiles. Accessed December 21, 2013 at

Carrel, J., E. Britt. 2009. The whip scorpion, Mastigoproctus giganteus (Uropygi: Thelyphonidae), preys on the chemically defended Florida scrub millipede, Floridobolus penneri) (Spirobolida: Floridobolidae). Florida Entomologist, 92/3: 500-502.

Cloudsley-Thompson, J. 1968. Spiders, Scorpions, Centipedes and Mites. Oxford, England: Pergamon Press.

Crawford, C., J. Cloudsle. 1971. Water relations and desiccation-avoiding behavior in vinegaroon Mastigoproctus giganteus (Arachnidae, Uropygi). Entomologia Experimentalis et Applicata, 14/1: 99-106.

Eisner, T., J. Meinwald, A. Monro, R. Ghent. 1961. Defense mechanisms of Arthropods.1. The composition and function of the spray of the whip scorpion, Mastigoproctus giganteus (Lucas) (Arachnida, Pedipalpida). Journal of Insect Physiology, 6/4: 272-298.

Hembree, D. 2013. Neoichnology of the whip scorpion Mastigoproctus giganteus: complex burrows of predatory terrestrial arthropods. PALAIOS, 28/3-4: 141-162.

Kern Jr., W., R. Mitchell. 2011. "Giant Whip Scorpion Mastigoproctus giganteus giganteus (Lucas, 1835) (Arachnida: Thelyphonida (Uropygi): Thelyphonidae)" (On-line). University of Florida. Accessed December 21, 2013 at

Punzo, F. 2005. Neem seed extract containing azadirachtin affects mortality, growth, and immunological function in the whipscorpion Mastigoproctus giganteus (Lucas) (Arachnida, Uropygi). Bulletin of Environmental Contamination and Toxicology, 75/4: 684-690.

Punzo, F. 2006. Types of shelter sites used by the giant whipscorpion Mastigoproctus giganteus (Arachnida, Uropygi) in a habitat characterized by hard adobe soils. Journal of Arachnology, 34/1: 266-268.

Schmerge, J., D. Riese, S. Hasiotis. 2013. Vinegaroon (Arachnida: Thelyphonida: Theylyphonidae) trackway production and morphology: implications for media and moisture control on trackway morphology and a proposal for a novel system of interpreting Arthropod trace fossils. PALAIOS, 28/1-2: 116-128.

Weygoldt, P. 1970. Courtship Behaviour and Sperm Transfer in the Giant Whip Scorpion, Mastigoproctus giganteus (Lucas) (Uropygi, Thelyphonidae). Behaviour, 36: 1-8.

Weygoldt, P. 1971. Life history and reproductive biology of giant whip scorpion, Mastigoproctus giganteus (Uropygi, Thelyphonidae) from Florida. Journal of Zoology, 164/2: 137-147.

University of Michigan Museum of ZoologyNational Science Foundation

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Miner, A. 2014. "Mastigoproctus giganteus" (On-line), Animal Diversity Web. Accessed May 22, 2024 at

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