Shell mats associated with microsporida in Biomphalaria glabrata: genetic studies

Multilayered mats have been observed lining the shell of some Biomphalaria glabrata infected with Steinhausia brachynema. Occurrence of the mats is associated with extensive infection with the microsporidia in these snails, in contrast to most B. glabrata in which infection appears restricted to the intestinal wall. Observations suggest that this variation in pathology may be influenced by a genetic difference in the host snails.