|MadSci Network: Zoology|
A true daddy-longlegs (also called a harvestman) is an arachnid, but not a spider. Spiders are arachnids with two major body parts, while true daddy long legs have all body parts fused into what appears to be one pill- like mass (the abdomen part of the pill is segmented, but the segments are usually not distinct to the eye). True daddy-longlegs are in the order Opiliones or Phalangida (you see both used in various books), while spiders are in the order Araneae. There are spiders that have been called daddy-longlegs spiders (family Pholcidae), but these build webs and obviously have two distinct body parts. True daddy long legs do not produce silk, as spiders do. Daddy-longlegs, like most arachnids, are predators, eating small invertebrates. Reference: Arachnology: The Study of Arachnids- Opiliones. http://www.ufsia.ac.be/Arachnology/Pages/Opiliones.html
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