Question

match the item with the structure of the starfish.

image of starfish structure with numbered parts and options: ring canal, water vascular system, ampullae

Explanation:

To solve this matching problem, we analyze the starfish's water vascular system structures:

1. Ring Canal: It is a circular canal around the central disc of the starfish, part of the water vascular system. In the diagram, the structure labeled (or associated with the central circular region) corresponds to the Ring Canal.
2. Water Vascular System: This is the entire system of canals (including the ring canal, radial canals, ampullae, etc.) used for locomotion, feeding, etc. The broader system encompassing the ring canal and radial canals fits this.
3. Ampullae: These are bulb - like structures associated with the tube feet (along the radial canals). In the diagram, the structures near the radial canals (like the ones with labels 20, 21) are Ampullae.

Matching:

• The circular canal around the central disc → Ring Canal
• The entire network of canals (ring + radial + ampullae) → Water Vascular System
• The bulb - like structures along radial canals → Ampullae

If we assume the dashed boxes:

• The central circular dashed box (around the central disc) → Ring Canal.
• The broader dashed box encompassing the central and radial canals → Water Vascular System.
• The small dashed box (or the structures near the radial canals, e.g., near 20, 21) → Ampullae.

Answer:

• Central circular structure: Ring Canal
• Entire canal network: Water Vascular System
• Bulb - like structures on arms: Ampullae

(Adjust based on the exact diagram’s dashed box positions; the key is identifying each structure’s typical location: Ring Canal (central ring), Water Vascular System (whole network), Ampullae (bulbs on radial canals).)