Identification
Arthropods can most easily be identified because they have (in some stage of their life cycle) segmented bodies with legs and other appendages jointed. They have an exoskeleton with no internal skeleton.
Annelids (earthworms, marine worms, leeches, etc) have segmented bodies(lots of segments!), but no jointed appendages(sometimes unjointed ones):
Molluscs have unjointed appendages (in the case of land snails and slugs, eye-stalks- which are really modified tentacles) and their bodies are unsegmented:
Flatworms have no segmentation or appendages of any kind:
Horsehair worms don't either:
Vertebrates have an internal skeleton, with no segmentation, and no externally-jointed appendages:
Also excluded (for the time being anyhow) are strictly aquatic Arthropod groups such as Crustaceans, except for the few exceptions that are terrestrial (aquatic members of terrestrial groups like insects are ok):
Chart of Animal Phyla
Remarks
While many of us in the BugGuide community are interested in all kinds of animals, BugGuide itself deals only with terrestrial arthropods: when this site was created, it was decided not to include any other groups of invertebrates so our talent, effort and expertise wouldn't be spread too thin. In fact, this group is so huge and complex, no one could begin to cover it all, even without the distraction of all the other groups.
This section is here to show some of the non-arthropod creatures most often submitted for identification. The idea is to only show a few representative types to give people a better idea of the limits of BugGuide- not to systematically cover anything.
Please don't add images here. There should enough images that show up in ID Request by mistake to populate this section, so no more submissions will be needed.
Note to editors: Please make sure the Representative check-box/flag is cleared.
