Trichomaris invadens gen. et sp. nov., an ascomycete parasite of the tanner crab (Chionoecetes bairdi Rathbun Crustacea; Brachyura)

Abstract

Trichomaris invadens Hibbits, Hughes and Sparks, gen. et sp. nov., an apparent obligate parasite of the tanner crab, Chionoecetes bairdi Rathbun, is described. This marine ascomycete is characterized by black, globose, aparaphysate perithecia borne on and in a subiculum of darkly pigmented encrusting hyphae on the exterior of the carapaces and appendages of host crabs; by two-celled ascospores bearing an unusually long, hairlike appendage at either end; and by internal hyphal invasion and destruction of host tissues following penetration of the carapace. Trichomaris invadens is the first pyrenomycete known to parasitize a marine crustacean. Observations on the pathogenicity of the fungus are included.