Animal Diversity Web

Geographic Range

Euscorpius flavicaudis is found mainly in Europe, at regions below 500 m altitude. Its northern most point of distribution is Krems in Austria. Its southern most point of distribution is North Africa. Specific colonies of E. flavicaudis are most commonly found in the south of France, northern Italy, and the United Kingdom. The largest colony of E. flavicaudis is found at Sheerness, Kent, in th U.K. (Grzimek, 1972; Hjelle, et al., 1990; Grzimek, 1972; Hjelle, et al., 1990)

• Biogeographic Regions
• palearctic
  • native

Habitat

Euscorpius flavicaudis dwells in cracks and crevices, and other dark, dry spaces. They are found in areas where human activity is low, and at altitudes less than 500 meters. (Benton, 16 May 1992; Benton, March 1992)

• Habitat Regions
• temperate

• Other Habitat Features
• urban
• suburban
• agricultural

• Range elevation

  500 (high) m

  1640.42 (high) ft

Physical Description

The body of the scorpion is black, and divided into two main sections. These are the cephalothorax, and the abdomen. The abdomen is further subdivided, and includes a large section that makes up the tail. The tail also is divided into four to five sections and at the endmost point of the "tail" is a stinger. There are four pairs of yellow and black striped legs, and two claws that are used for prey capture, battle, and mating rituals. Most of the scorpion's body is covered with small hairs that act as sensory equipment for the scorpion. Euscorpius flavicaudis shares its features with virtually all other species of scorpions, but is unique due to its incredibly small size. As an adult the scorpion ranges in size from 35-45 mm in length. There is no sexual dimorphism. (Benton, 18 May 1991; Highfield, August 14, 1995; Hjelle, et al., 1990)

• Other Physical Features
• ectothermic
• heterothermic
• bilateral symmetry
• venomous

• Sexual Dimorphism
• sexes alike

• Range mass

  .3 to 1.1 g

  0.01 to 0.04 oz

• Average mass

  0.70 g

  0.02 oz

• Range length

  35 to 40 mm

  1.38 to 1.57 in

Development

The female scorpion holds the fertilized eggs inside of her until they are ready to hatch. She then lays the eggs, and eggs hatch as fully developed juvenile scorpions almost immediately. The female will carry her young on her back until they are too large to all fit. The gestation period is not known for certain in this particular species of scorpion, but it is thought that the female holds in the eggs for aproximately 10 months. (Benton, 16 May 1992; Benton, 18 May 1991; Benton, March 1992; Grzimek, 1972)

• Development - Life Cycle
• metamorphosis

Reproduction

The mating season occurs during the warmest months of the year: June, July, and August. It has been noted that the length of the mating season is directly proportional to the duration of the warm weather. At the beginning of the mating season there are two types of females, those who are still pregnant, and those that for some reason did not mate the previous year. Population sizes are small, and the distance between populations is large. It is for this reason that males are very protective of any female that they encounter. If a male comes upon a female who is a viable mate, but is not yet receptive at that time, the male will stay in the same crack protecting the female from other males until she becomes receptive to him. When a female is receptive to mating, the male and female grasp the pedipalps of the other and circle eachother in what is called the scorpion dance. After this courtship dance, the male deposits a packet of sperm on the substrate. He then pulls his mate under him until her sexual opening is above his spermatophore, and she picks it up.

Females never mate more than once per season, and sometimes not at all. Males often mate more than once per season, although some do not mate at all. Males that do mate more than once are almost always at the larger end of the size spectrum. (Benton, 16 May 1992; Benton, 18 May 1991; Benton, March 1992; Grzimek, 1972; Benton, 16 May 1992; Benton, 18 May 1991; Benton, March 1992; Grzimek, 1972; Benton, 16 May 1992; Benton, 18 May 1991; Benton, March 1992; Grzimek, 1972)

• Mating System
• polygynandrous (promiscuous)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• sexual
• fertilization
  • internal
• ovoviviparous

• Average gestation period

  10 months

The female scorpion holds the fertilized eggs inside of her until they are ready to hatch. She lays the eggs and the eggs hatch almost immediately as fully developed juvenile scorpions. The female will carry her young on her back until they are too large to all fit.

Males leave soon after copulation and assume no responability for the young. (Benton, 16 May 1992; Benton, 18 May 1991; Benton, March 1992; Grzimek, 1972)

• Parental Investment
• pre-fertilization
  • provisioning
  • protecting
    • female
• pre-hatching/birth
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female
• pre-independence
  • provisioning
    • female
  • protecting
    • female

Behavior

Euscorpius flavicaudis are nocturnal, leaving the safety of their hiding place at dusk, and with peak activity occuring soon afterr.

In studies, scorpions were found to have three distinct states of being: moving, alert but immobile, or completely unalert. These states are distinguishable by posture. The alert but immobile scorpion has pedipalps protracted, claws open, and a raised body. In an unalert stage the exact opposite occurs. During the light hours Euscorpius flavicaudis is found in the very back of its hiding spot in this relaxed position. As night sets in the scorpion moves towards the front of its crack and becomes more alert.

These scorpions very rarely leave the protection of their cracks. The only reasons to leave are mating and eating. Leaving the hiding spot is also dependent upon time of year as scorpions are more active during the summer months. Males' activity level forms a linear relationship to temperature with peak activity just before mating season. The females' activity level also somewhat correlates with temperature, but female becomes much less active after mating, even in warm temperatures. Females are most active right after they give birth, and again once their litter is no longer riding on their back. Females carry the young on their back until the babies are older than two months.

Scorpions are fierce predators. They sit at the front of their crack waiting for prey to walk by. Approaching prey are detected by hairs on the pedipalps. Prey is immobilized using the claws, as this scorpion species rarely uses its sting. Once the prey item is dead the scorpion goes back into its crack to eat its meal. Prey is eaten head first. If the night is young the scorpion may go to the entrance of the crack a second time, but most likely it will only feed once per night. Scorpions who were not fortunate enough to find a meal will retreat back into their cracks at the first light of dawn. Euscorpius flavicaudis are capable of surviving long periods of time with out food. (Benton, 16 May 1992; Benton, March 1992)

• Key Behaviors
• nocturnal
• crepuscular
• motile
• sedentary

Food Habits

Euscorpius flavicaudis is an ambush predator. They lie safely and quietly at the entrance to their home, moving quickly to retrieve prey that has unfortunately wandered past. The main prey of E. flavicaudis are woodlice, although most small insects will do. Canabalism has been noted in colonies of E. flavicaudis, the larger scorpion always wins, and the smaller scorpion is then eaten. It is during these intense battles and while in pusuit of prey that the scorpions poisonous sting is used. Scorpions may go long periods of time without food. Scorpions may not have very many opportunities to feed, although they hunt every night. (Benton, 16 May 1992; Benton, 18 May 1991; Benton, March 1992)

• Primary Diet
• carnivore
  • insectivore

• Animal Foods
• insects

Economic Importance for Humans: Positive

Euscorpius flavicaudis has no known economic importance to humans.

Economic Importance for Humans: Negative

Euscorpius flavicaudis has no known negative economic importance.

Conservation Status

Euscorpius flavicaudis is found in extremely small numbers. This makes the scorpion difficult to find, but it require a special conservation status.

• IUCN Red List

  No special status

• US Federal List

  No special status

• CITES

  No special status

Contributors

Sara Diamond (editor), Animal Diversity Web.

Jennifer Akre (author), Southwestern University, Stephanie Fabritius (editor), Southwestern University.

References

Benton, D. 16 May 1992. Scorpions in a Cold Climate. New Scientist: 15.

Benton, T. 18 May 1991. Scorpion Mating Sucess. Animal Behaviour: 125-135.

Benton, T. March 1992. The ecology of the scorpion Euscorpius flavicaudis in England.. Journal of Zoology, 226: 351-368.

Grzimek, D. 1972. Grzimek's Animal Life Encyclopedia. New York: Van Nostrand Reinhold Company.

Highfield, R. August 14, 1995. Beauty and some not so lovely beasties invade tropical Britain. Daily Telegraph.

Hjelle, J., D. Sissom, G. Polis, M. Warburg, S. Mc Cormick. 1990. The Biology of Scorpions. Standford, California: Standford University Press.