GENERAL HISTOLOGY

Detailed explanation-1: -All echinoderms have unique hydraulic structures called tube feet, known for their roles in light sensitivity, respiration, chemoreception and locomotion.

Detailed explanation-2: -The tube feet are slender tubes that extend as water is pumped into them. Water enters through a sieve plate in the starfish’s skin and is forced by muscles into each tube foot. The water extends the length of the cavity of the tube foot.

Detailed explanation-3: -Tube feet function in locomotion, feeding, and respiration. The tube feet in a starfish are arranged in grooves along the arms. They operate through hydraulic pressure. They are used to pass food to the oral mouth at the center, and can attach to surfaces.

Detailed explanation-4: -An echinoderm moves by using many tube feet. Tube feet are small, delicate projections attached along the side of a water-filled tube called a radial canal.