Stygobromus ephemerus (Holsinger 1969)

Stygobromus ephemerus (Holsinger)

Apocrangonyx species C.—Holsinger, 1969a:28.

Apocrangonyx ephemerus Holsinger, 1969b:18–22, figs. 7, 8 [type-locality: Tawneys Cave, Giles Co., Virginia]; 1972:54.

Stygobromous ephemerus (Holsinger).—Karaman, 1974:110.—Holsinger, 1977:261.

MATERIAL EXAMINED.—VIRGINIA. Giles Co.: Tawneys Cave, 1 , G. Marland, Feb 1962; 1 , J. R. Holsinger and E. Bauer, 20 Aug 1965.

DIAGNOSIS.—A moderately small cavernicolous species, but one of the larger members of the ephemerus group, distinguished by having about 13 spine teeth on propod of gnathopod 1 and about 10 spine teeth on propod of gnathopod 2, relatively narrow bases of pereopods 5–7, and short, unnotched telson which is about as broad as long. Largest male, 3.4 mm; largest female, 5.0 mm.

DISTRIBUTION AND ECOLOGY.—This species is recorded from Tawneys and Canoe caves, which are situated about 4 km apart in the Sinking Creek Valley of Giles Co., Virginia (Holsinger, 1969b:22). Stygobromus ephemerus inhabits mud-bottom, drip, and seep pools in both caves and occurs sympatrically with S. mackini in Tawneys Cave. Females (3.5–5.0 mm) with setose brood plates have been collected during summer, fall, and winter but none have been ovigerous.

Stygobromus ephemerus, commonly called ephemeral cave amphipod, is a troglomorphic species of amphipod in family Crangonyctidae. It is endemic to Virginia in the United States.