Invertebrates have simpler but efficient excretory organs suited to their body type and habitat. These structures remove nitrogenous wastes and help in maintaining salt and water balance.

Examples

• Flatworms: Flame cells (protonephridia).
• Earthworms: Nephridia in each segment.
• Insects: Malpighian tubules.‍
• Crustaceans: Green glands or antennal glands.