How do fairy shrimp differ from brine shrimp?

Fairy shrimp and brine shrimp are both crustaceans belonging to the order Anostraca and the class Branchiopoda, but they differ primarily in their habitats and taxonomic classification.123

• Habitat: Fairy shrimp are typically found in freshwater ponds and are often confined to temporary pools. In contrast, brine shrimp (genus Artemia) inhabit highly saline inland waters, such as brine pools.412
• Taxonomy: While both are in the order Anostraca, they are separated at the suborder level. Fairy shrimp belong to the suborder Anostracina, whereas brine shrimp belong to the suborder Artemiina.3
• Characteristics: Fairy shrimp are named for their graceful movements and pastel colors. Brine shrimp are smaller, measuring up to 15 mm (0.6 inch), and are known for swimming in an upside-down position by rhythmically beating their leaflike limbs.42

Because they occupy such distinct environments—freshwater versus highly saline water—these two groups have adapted to different ecological niches within the branchiopod class.412