| Name: | caudal fin | 
|---|---|
| Synonyms: | tail, tail fin | 
| Definition: | Fin that is the most posterior median fin. It is composed of a complex of three modified centra and modified neural and hemal arches and spines. | 
| Ontology: | Anatomy Ontology [ZFA:0001058] | 
| Name: | vein | 
|---|---|
| Synonyms: | venous system | 
| Definition: | Vessels that carry blood to the heart. | 
| Ontology: | Anatomy Ontology [ZFA:0000082] |