Earthworms and leeches belong to which phylum of segmented worms?

Earthworms and leeches belong to which phylum of segmented worms?

• A. Annelida
• B. Mollusca
• C. Arthropoda
• D. Echinodermata

Answer: (A)

Segmented body organization with a true coelom identifies earthworms and leeches as members of the phylum Annelida. Annelids have repeating body segments, a closed circulatory system, and a gut that runs through the length of the body, traits shared by both earthworms and leeches despite their different lifestyles. Other groups listed differ in fundamental ways: Mollusca includes animals like snails and clams that aren’t built from repeating segments; Arthropoda have segmented bodies plus an external skeleton and jointed limbs; Echinodermata exhibit radial symmetry and a water vascular system. Earthworms and leeches, therefore, belong to Annelida.

Segmented body organization with a true coelom identifies earthworms and leeches as members of the phylum Annelida. Annelids have repeating body segments, a closed circulatory system, and a gut that runs through the length of the body, traits shared by both earthworms and leeches despite their different lifestyles. Other groups listed differ in fundamental ways: Mollusca includes animals like snails and clams that aren’t built from repeating segments; Arthropoda have segmented bodies plus an external skeleton and jointed limbs; Echinodermata exhibit radial symmetry and a water vascular system. Earthworms and leeches, therefore, belong to Annelida.