Term: post-vent region ventral side
Name: post-vent region
Synonyms: tail
Definition: Organism subdivision which is the part of the body posterior to the vent which includes the anal and caudal fins.
Ontology: Anatomy Ontology [ZFA:0001117]

Name: ventral side
Synonyms: ventral
Definition: An anatomical region that is the entire part of an anatomical structure ventral to a horizontal plane and bounded on one side by the same horizontal plane.
Ontology: Spatial Ontology [BSPO:0000068]