Branchinecta hiberna, a new species of fairy shrimp (Crustacea : Anostraca) from western North America

Branchinecta hiberna, a new species of fairy shrimp, is described from temp orary pools in the Great Basin region of south central Oregon, northeastern California, and adjacent Nevada. The new species shares several characters with Branchinecta cornigera Lynch, 1958: males bear a similar large patch of small spines on the basal segment of antenna 2, and females bear the sim ilar robust antenna 2 with medial spur, brood pouch shape, and resting egg (cyst) morphology. The new species differs from B. cornigera in the shape o f the distal segment of antenna 2 and the number and size of spines on the paired penis warts of males, and in the thoracic spine pattern and lack of dorsal cephalic projections in females. Observations on behavior and ecolog y of B. hiberna are discussed.