A new pathology in the red abalone Haliotis rufescens (Mollusca: Gastropoda) cultured in Baja California, Mexico, associated with macro-crystal inclusions in gonadal tissue

A new severe pathological alteration in the gonadic tissue of red abalone was observed, which compromises reproduction of affected organisms. The alteration is related to the presence of numerous extracellular macro-crystal inclusions (Mci) reaching up to 300 ?m in size. These Mci may be surrounded by hemocytes, cellular debris, and deposition of fibroblasts. Moreover, hypertrophy of the nuclei of cells in the top germinal epithelium and presence of brown cells in trabeculae were observed. The normal architecture of the tissue looks entirely altered and destroyed in some cases. No gonadal development was observed. The chemical nature of the Mci is unknown, but it is possibly related to inorganic toxic compounds. No previous records of similar alterations in abalone are known to exist. This record could help determine if this pathology has been observed in other abalone culture areas in the world, its possible origin, and if control is necessary.