F
- Falcate: scythe-shaped, long, narrow, and curved
- Falciform: curved like a scythe
- Filament: a slender or thread-like structure
- Filiform: thread-like
- Fimbriate: fringed at the margin
- Finfold: embryonic tissue which develops into a fin
- Finlet: a small fin, positioned behind the dorsal or anal fins, that is supported by a ray or rays
- Fluviatile: living in rivers
- Free rear tips (of fins): the posterior tip of the fin that is closest to the most posterior point of the fin base
- Frontal ridge: a ridge running along the top of the head along the midline
- Furcate: forked
- Fusiform: tapering towards both ends
Read more about this topic: Mesocoracoid