Paradamoetas fontana    (Levi, 1951)

A Jumping Spider 


MN Status:

special concern
Federal Status:
none
CITES:
none
USFS:
none


Group:

spider
Class:
Arachnida
Order:
Araneae
Family:
Salticidae
Habitats:

(Mouse over a habitat for definition)


Paradamoetas fontana Paradamoetas fontana Paradamoetas fontana Paradamoetas fontana Paradamoetas fontana Paradamoetas fontana

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Map Interpretation

Map Interpretation

  Synonyms

Icius fontanus

  Basis for Listing

Paradamoetas fontana has a restricted range in the Great Lakes area of the United States and Canada. It occurs in Minnesota at the western periphery of its range, where it has been documented from less than 10 sites. This species preferred habitat is vulnerable to human disturbance, particularly drainage. Paradamoetas fontana was listed as a special concern species in Minnesota in 1996. Special concern spider species are those known from three or more sites in Minnesota, but with significant range restrictions or particular habitat associations that make their populations appear vulnerable from a conservation standpoint.

  Description

Jumping spiders are one of the most recognizable spiders, as they generally have a stout body, rather short legs, a very large set of eyes, and the ability to jump. They also walk with an irregular gait. Their body shapes and colors often imitate prey such as ants and beetles. Paradamoetas fontana is iridescent and ant-like in appearance. Culter (1982) gives taxonomic details for this species.

  Habitat

Paradamoetas fontana occurs in mesic prairie, bogs, and marsh edges. In 1996, the species was located near cattail marsh edges on grasses and near quartzite boulders and seeps (Ehmann and Boyd 1997).

  Biology / Life History

Jumping spiders do not spin webs for catching prey. Instead, they construct small tent-like silken retreats under rocks or logs, or on plants, which they use at night and during hibernation. The females will also lay their eggs in them. Jumping spiders are most active during the day, and they prefer sunshine. They tend to stay in their retreats on cloudy or rainy days. Jumping spiders are generally interested in whatever approaches them, and will often turn and face human observers, and may even advance towards them. They are generally harmless to people.

Jumping spiders have four pairs of eyes, with the pair of large principal eyes giving them better vision than other spiders. The forward-looking placement of this pair of eyes provides binocular vision, enabling them to judge distances accurately, and they are able to identify prey, predators, and mates from up to a foot away (Weber 2002). Physiological and behavioral experiments have demonstrated that they have color vision, possibly extending into the ultraviolet range.

Jumping spiders feed primarily on insects, although some may feed on web-building spiders. They will also feed on other jumping spiders, usually those that are smaller than themselves. Jumping spiders actively stalk their prey instead of snaring it in a web. They may however, steal insects snared by the webs of other spiders. Jumping spiders hunt primarily during the day, using their keen eyesight to find prey. Having spotted a potential victim, a jumping spider will slowly stalk the prey until it is within jumping distance. Then, it lifts its front legs and pounces. Like all spiders, jumping spiders move their legs not by muscular contractions but by changing the pressure of the fluid within them. This hydraulic system enables them to jump up to several times their body length without having large, muscular legs. Before jumping, the spider always affixes a silk safety line to whatever it is jumping from; in case it falls it can climb back up this tether.

The visual capabilities of jumping spiders that are critical to their performance as hunters also support complex courtship behaviors. Males often differ in appearance from females and my have colorful, sometimes iridescent modifications to their bodies, front legs, or mouthparts. The parts of the male's body that are used in courtship are often conspicuously colored. In many jumping spider species, the males perform courtship dances in front of the female that are specific to each species. The male's movements range from a slight lifting of a leg to complex movements, such as bobbing their bodies, twitching their abdomen, performing zigzag movements, waving their front legs, or flashing their mouthparts into the eyes of the females. Some male jumping spiders may also have auditory signals which when amplified sound like buzzes or drum rolls. It is presumed that females choose mates based on their courtship dances. After mating, females lay their eggs in their silken retreat, and will often guard their eggs and newly hatched young.

  Conservation / Management

Paradamoetas fontana is a Great Lakes region endemic (Cutler 1981; Wolff 1984), and is best known from Minnesota, suggesting that the Minnesota populations could play a significant role in conserving this species (see also Richman and Cutler 1977). The best time to search for this species is from June through September. Although remnants of natural areas may often be too small or isolated for some rare vertebrates, they may be suitable for maintaining invertebrates. Each new locality for a species adds to the suite of management options for their conservation and may even guide new land designations or acquisitions. Benign to humans, diverse, colorful, and behaviorally complex, jumping spiders may be good ambassadors for their kin and invertebrates in general.

  Conservation Efforts in Minnesota

Several known Minnesota localities of P. fontana are protected including the Cedar Creek Natural History Area and Helen Allison Savanna Scientific and Natural Area (SNA) in Anoka County, and the Roscoe Prairie SNA in Stearns County. Because similar habitats have been sampled elsewhere in the state without success, P. fontana appears to be uncommon in Minnesota. It is possible that future sampling with waders or from boats may produce additional records, and any new records will be of interest.

  References

Cutler, B. 1981. A revision of the spider genus Paradamoetas (Araneae, Salticidae). Bulletin of the American Museum of Natural History 170:207-215.

Cutler, B. 1982. Description of a new species of Paradamoetas (Araneae, Salticidae), with a revised key to the genus. Great Lakes Entomologist 15:219-222.

Ehmann, W. J. 2002. Conservation biology of special concern jumping spiders (Araneae: Salticidae) of Minnesota. Final Report submitted to the Natural Heritage and Nongame Research Program, Minnesota Department of Natural Resources. 11 pp.

Ehmann, W. J., and B. E. Boyd. 1997. Surveys for proposed special concern jumping spiders of Minnesota. Final report submitted to the Minnesota Department of Natural Resources. Unpaged.

Foelix, R. F. 1996. Biology of spiders. Oxford University Press, New York. 330 pp.

Forster, L. M, and M. R. Forster. 1999. How do jumping spiders catch up on their prey?: a model for pursuit behaviour. (Araneae; Salticidae) - a preliminary draft. <http://philosophy.wisc.edu/forster/Spider/Default.htm>. Accessed 16 Aug 2006.

Maddison, W. 2006. Jumping spiders of American north of Mexico. <http://tolweb.org/accessory/Jumping_spiders_of_America_North_of_Mexico?acc_id=66>. Accessed 16 Aug 2006.

Richman, D. B., and B. Cutler. 1977. A list of jumping spiders (Araneae: Salticidae) of the United States and Canada. Peckhamia 1:82-109.

Weber, L. 2002. Spiders of the North Woods. Kollath-Stensaas Publishing, Duluth, Minnesota. 205 pp.

Wikipedia contributors. 2010. Jumping spider. Wikipedia, The Free Encyclopedia. <http://en.wikipedia.org/wiki/Jumping_spider>. Accessed 15 April 2010.

Wolff, R. 1984. A preliminary list of the salticids of the Great Lake states. Peckhamia 2:57-62.