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General Features of Chordates

Chordates are a diverse group of animals characterized by specific features at some stage of their life cycle. The main general features include:

1. Notochord: A flexible rod-like structure that provides support. It develops into the vertebral column in vertebrates.

2. Dorsal nerve cord: A hollow tube that becomes the central nervous system, including the brain and spinal cord.

3. Pharyngeal slits: Openings that connect the pharynx to the outside, used for filter feeding in some chordates and develop into gill structures in aquatic species.

4. Post-anal tail: An extension of the chordate body beyond the anal opening, providing propulsion in water for many aquatic species.

5. Endostyle or thyroid gland: Involved in the metabolism of iodine and helps with filter feeding in some taxa.

Check List for Amphioxus Slide

• Oral Cirri:

  • Function: Used for filter feeding; they help to trap food particles from water as it enters.

• Notochord:

  • Function: Provides structural support and maintains body shape; is essential for locomotion and development of the spine.

• Dorsal nerve cord:

  • Function: Responsible for transmitting nervous signals; plays a crucial role in the coordination of movement and reflexes.

• Dorsal fin:

  • Function: Aids in stability and provides better maneuverability during swimming.

• Gill slits:

  • Function: Facilitate respiration and feeding; allow water to pass from the pharynx to the outside environment to filter food or extract oxygen.