Spirurida
| Spirurida | |
|---|---|
| Dirofilaria immitis larva Magnification 400× | |
| Scientific classification | |
| Domain: | Eukaryota | 
| Kingdom: | Animalia | 
| Phylum: | Nematoda | 
| Class: | Chromadorea | 
| Order: | Rhabditida | 
| Suborder: | Spirurida | 
| Superfamilies | |
| 10, but see text | |
Spirurida falls under the phylum Nematoda class Chromadorea and order Rhabditida. They are characterized by their elongated, cylindrical bodies and unsegmented structure. Like all nematodes, they have neither a circulatory nor a respiratory system. 
Some Spirurida, like the genus Gongylonema, can cause disease in humans. One such disease is a skin infection with Spirurida larvae, called "creeping disease". Some species are known as eyeworms and infect the orbital cavity of animal hosts.