Caponiidae
| Caponiidae | |
|---|---|
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Left:Nops guanabacoae |
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| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Subphylum: | Chelicerata |
| Class: | Arachnida |
| Order: | Araneae |
| Infraorder: | Araneomorphae |
| Family: |
Caponiidae Simon, 1890 |
| Genera | |
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See text. |
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| Diversity | |
| 11 genera, 70 species | |
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Left:Nops guanabacoae
Middle and right:Cubanops alayoni female and male
See text.
Spiders of the ecribellate haplogyne family Caponiidae are unusual in a number of ways. They differ from other spiders in lacking book lungs and having the posterior median spinnerets anteriorly displaced to form a transverse row with the anterior lateral spinnerets. Most species have only two eyes, which is also unusual among spiders. A few species of Caponiidae variously have four, six or eight eyes. In some species the number of eyes will increase when the spiderling changes its skin as it grows towards adulthood.
These spiders of about 2 to 5 mm are rarely noticed, but generally look like somewhat faded woodlouse hunter spiders in the genus Dysdera. The carapace (cephalothorax or prosoma) is orange and the abdomen (opisthosoma) light gray. The two-eyed species have their two eyes in the anterior middle of the carapace.
Caponiidae are unusual in the degree to which the eye number varies. In this they surpass even the family Cybaeidae in which some species have two eyes, some six, and some eight. In some species of the Caponiidae paired eyes meet in the midline, giving the spider in effect, an odd number of eyes. The following genera have eyes as follows:
Their habits are for the most part unknown. At least some species are known to hunt other spiders.
The fact that they are ecribellate and haplogyne suggests that they might be relatively primitive. Calponia harrisonfordi from California seems to be the most primitive member of the family. Their phylogenetic relationships have long been enigmatic, but in the early 1990s it was determined that they are probably a sister group of the Tetrablemmidae plus the four families inside the Dysderoidea superfamily.
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Wikipedia