Rotifera excretory system includes which of the following?

Rotifera excretory system includes which of the following?

• A. Protonephridia and flame cells
• B. Metanephridia
• C. Malpighian tubules
• D. Nephridia

Answer: (A)

Rotifera use a protonephridial excretory system with flame cells. These are simple tubules ending in flame cells, which beat cilia to draw body fluids into the tubules and push waste out to the exterior through an excretory pore. This setup is well-suited for their pseudocoelomate body plan and freshwater lifestyle, providing both waste removal and osmoregulation by managing excess water and dissolved materials. Other types of excretory organs—metanephridia, Malpighian tubules, or nephridia—are found in different groups (such as annelids, mollusks, and insects) and involve more complex arrangements with nephrostomes or gut connections. Those structures don’t match the rotifer anatomy or its mode of waste disposal, so the protonephridial system with flame cells is the correct description for Rotifera.

Rotifera use a protonephridial excretory system with flame cells. These are simple tubules ending in flame cells, which beat cilia to draw body fluids into the tubules and push waste out to the exterior through an excretory pore. This setup is well-suited for their pseudocoelomate body plan and freshwater lifestyle, providing both waste removal and osmoregulation by managing excess water and dissolved materials.

Other types of excretory organs—metanephridia, Malpighian tubules, or nephridia—are found in different groups (such as annelids, mollusks, and insects) and involve more complex arrangements with nephrostomes or gut connections. Those structures don’t match the rotifer anatomy or its mode of waste disposal, so the protonephridial system with flame cells is the correct description for Rotifera.