Dolomedes minor
| Dolomedes minor | |
|---|---|
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| Female guards nursery web | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Arachnida |
| Order: | Araneae |
| Family: | Pisauridae |
| Genus: | Dolomedes |
| Species: | D. minor |
| Binomial name | |
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Dolomedes minor (L. Koch, 1876) |
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The nursery web spider (Dolomedes minor) is a spider indigenous to New Zealand.
Dolomedes minor is pale brown with some being grayish, like the rocks around which they live, helping to camouflage them against predators. (Arnqvist, 1992) The spider has large pedipalps, which are usually used for sensory purposes. The palps in the male Dolomedes minor are modified for putting sperm into the female's epigyne, which is located on the underside of the female's abdomen. The female Dolomedes minor can easily be identified based on this location of the epigyne. They possess large chelicerae, which are located just below the eyes. (Andrews, 1986) The spider has a body length of about 18 mm. The females are almost twice the size of the males. They move very fast and possess a long leg-span: over sixty millimeters for a fully grown female.
The family Pisauridae, containing all nursery web spiders, has been estimated to contain over 300 species. However, Dolomedes minor is the only species endemic to New Zealand.
Dolomedes minor can be found throughout New Zealand in various vegetation types and altitude ranges.
Dolomedes minor is found in a variety of habitats throughout New Zealand. They survive in a variety of terrains, from sea level up to subalpine areas, including shrubland containing Gorse (Ulex europaeus) and Manuka (Leptospermum scoparium), swamps and grasslands. When hunting, they can be seen waiting around the water's edge and active amongst the stones, although they are nocturnal hunters. The spider is noticeable in these areas due to the large white nests thickly webbed to the ends of plants throughout these regions. Females will usually remain with their young in these habitats once their nursery webs have been constructed.
Dolomedes minor are most commonly seen through the summer months from November to May. Over these months the females have been found with egg-sacs attached to them which are carried for at least 5 weeks in their fangs. After this the female will start to construct her nursery web, which is not made to catch prey but to ‘nurse’ young. This is made at night and built amongst and at the tips of foliage. It can be around six inches or more in length and will house the eggs and young. At night the females guard the web and during the day have been noted to move towards the base of the vegetation. The spiderlings will emerge shortly after the webs construction, usually within a week or after they have changed skin, and after two weeks most young would have left the nest. It is presumed this is done by ‘ballooning’ a type of air dispersal to allow them to leave the nest. This air dispersal is done so on long floating strands of silk which can also aid leaving and moving to a variety of geographical boundaries. There has been sightings of adult males with young adult females but no courtship or mating has been recorded. In other Dolomedes species, sexual cannibalism is high so it is possible that D. minor males will try mate with virgin females to avoid this. Hurried copulation (mating) has been found to be common in Dolomedes species also.
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Wikipedia