Which characteristics are shared by these 3 arthropods?

Question

A grasshopper, a spider, & a crawfish.

there are a few characteristics shared by each when disected, or not... but i do not know what they are.

please help, thanks!

Answer 1

*  Two body regions (cephalothorax and abdomen)

• Cephalothorax with 6 pairs of appendages (chelicerae,    pedipalps and 4 pairs of walking legs)

• Abdomen with up to 3 pair of appendages (spinnerets)

Answer 2

They all have: exoskeletons,                                                                                   open circulatory systems,                                                            jointed legs, segmented bodies

Answer 3

they are also true coelemates, have mandibles, and book lungs/gills