Aquatic vertebrate and Jawless vertebrate

Aquatic vertebrate noun - Animal living wholly or chiefly in or on water.

Jawless vertebrate and aquatic vertebrate are semantically related. In some cases you can replace phrase "Jawless vertebrate" with "Aquatic vertebrate", this phrases are similar.

Jawless vertebrate noun - Eel-shaped vertebrate without jaws or paired appendages including the cyclostomes and some extinct forms.

Aquatic vertebrate and jawless vertebrate are semantically related. You can use "Aquatic vertebrate" instead a noun phrase "Jawless vertebrate".