Fish Skeletal System

1. Skull (Cranium)

• Protects the brain and sensory organs (eyes, olfactory structures).

• Includes the jawbones:

  • Maxilla & Premaxilla – Upper jaw bones that aid in feeding.

  • Mandible – Lower jaw bone responsible for mouth movement.

• Operculum – A bony plate covering and protecting the gills.

2. Vertebral Column (Axial Skeleton)

• Made up of vertebrae that provide support and flexibility.

• Extends from the skull to the tail, allowing movement and protection of the spinal cord.

3. Fin Supports (Appendicular Skeleton)

• Fin Rays (Lepidotrichia) – Bony or cartilaginous structures that support the fins.

• Dorsal Fin – Helps maintain balance and prevent rolling.

• Pectoral Fins – Assist in steering and maneuvering.

• Pelvic Fins – Aid in stability and stopping.

• Anal Fin – Helps with stability in swimming.

• Caudal Fin (Tail Fin) – Provides propulsion for movement.

4. Pectoral and Pelvic Girdles

• Pectoral Girdle – Connects the pectoral fins to the axial skeleton.

• Pelvic Girdle – Supports the pelvic fins and aids in balance.

5. Ribcage and Internal Support

• Ribs – Provide protection for internal organs and assist in body structure.

• Intermuscular Bones – Small bones that contribute to body rigidity and flexibility.