Branchinecta mackini

Irving P.
Oct 2, 2023
2 min read

Updated: Aug 31

Taxonomy and Classification

• Phylum: Arthropoda

• Class: Branchiopoda

• Order: Anostraca

• Family: Branchinectidae

• Genus: Branchinecta

• Species: B. mackini

• Authority: Dexter, 1956

Branchinecta mackini, commonly known as the Alkali Pool Fairy Shrimp, belongs to the order Anostraca and the family Branchinectidae. First described by Dexter in 1956, this species thrives in ephemeral alkaline environments such as dry lake beds and saline playas. These habitats are typically composed of sand, loam, and clay soils enriched with chemical compounds like calcium sulfate, calcium carbonate, and sodium salts. The pools are often turbid and highly saline, forming during cooler seasons—especially winter and spring—when precipitation temporarily fills these basins.

The distribution of B. mackini is broad across western North America, ranging from Canada to Mexico, with a strong presence along the Pacific Coast and interior regions of the western United States. Documented populations include sites in Washington, California, and other arid or semi-arid zones where suitable alkaline conditions exist

The characteristics outlined below may exhibit variations influenced by environmental conditions, population dynamics, and the organism's age.

IDENTIFIABLE TRAITS OF THIS SPECIES

Male Second Antenna:

Branchinecta is a diverse genus of fairy shrimp characterized by a suite of morphological traits that facilitate species-level identification and ecological specialization. Males exhibit pronounced sexual dimorphism, particularly in the second antennae, which are often modified into grasping structures used during mating. These antennae vary in shape, segmentation, and presence of distal lobes or hooks, serving as reliable taxonomic markers.