-Priyanti, Subject Matter Expert at Edumarz
Solution: Both annelids and arthropods have segmented bodies. Annelida have metameric segmentation and their bodies are not distinguished into head, thorax and abdomen. Arthropods, however, have well-developed cephalic, thoracic and abdominal regions.
Annelids have unsegmented appendages and arthropods have segmented or jointed appendages.
Annelids have true coelom (schizocoel) while arthropods possess a coelom filled with circulatory fluid (haemocoel). This is due to the fact that the latter have an open circulatory system as opposed to the former, whose circulatory system is closed.
Annelids have red blood as they have hemoglobin as their respiratory pigment. In arthropods, blood is colorless or bluish as they lack respiratory pigments.