Hint: Annelids are the animals that are referred to as segmented worms, while arthropods are referred to as animals with jointed legs. An example of annelids is the earthworm and an example of arthropods is the Housefly.
Complete answer:
Phylum Annelids and Phylum Arthropods both belong to Non chordates as Notochord is absent. However both the phyla have certain differences and these differences are as follows:
| Characteristics | Phylum Annelida | Phylum Arthropods |
| Definition | The organisms show the presence of Annulus (rings or segments) all over the body. | Arthros means joints and poda means feet. Thus animals of this group have jointed feet. |
| Exoskeleton | Absent | Chitinous exoskeleton |
| Locomotion | Setae or parapodia for locomotion | Jointed feet for locomotion |
| Body division | Lacks distinct head | Body is divided into head, thorax and abdomen |
| Sexes | Hermaphrodite | Unisexual |
| Circulatory system | Closed | Open |
| Respiratory organ | skin | Lungs, gills, trachea |
Note: Arthropods are more evolved than Annelids. However Arthropods show open circulation and Annelids show close circulation. This is because Arthropods have a property of ecdysis (shedding of skin). Thus the blood vessels too can get destroyed hence they have open circulation.
Arthropods are still more evolved than Annelids because they show a well developed tracheal system and hence in these animals the respiratory system is not dependent on the circulation system.
Annelids are invertebrate worms with over 17,000 known species. Annelids can be found in most wet environments. Some of these species are parasitic or mutualistic. Arthropods from the phylum Euarthropoda, which includes insects, arachnids, myriapods, and crustaceans.
