87.4 Sunday, Jan. 6 Separating the effects of the deposition substrate and habitat on the anti-microbial properties of egg masses of Haminoea vesicula SMOOT, S.C.*; PLANTE, C.J.; PODOLSKY, R.D.; College of Charleston; College of Charleston; College of Charleston email@example.com
Several marine invertebrates reproduce by encapsulating embryos inside gelatinous egg masses until hatching. Previous studies have shown that the anti-microbial activity of egg masses of a given species can vary among field locations. This observation suggests that anti-microbial activity may be affected by the nature of the deposition substrate or by other aspects of between-site variation. If differences in anti-microbial activity across habitats depend strongly on the deposition substrate, then adults provided different substrates in a common garden should produce egg masses with different levels of anti-microbial activity. We compared anti-microbial activity in egg masses of the opisthobranch mollusc Haminoea vesicula in two ways: when laid on different macrophyte substrates at a single field site, and on the same substrate (the green alga Ulva lactuca) at different field sites. Methanol (MeOH) and ethyl acetate (EtOAc) extracts were then tested for anti-microbial activity against marine type cultures and several environmental strains using a 96-well plate bacterial growth assay. The level of anti-microbial activity depended strongly on the substrate the egg mass was laid on and minimally on the field site. These results suggest that chemicals produced by macrophytes or their associated microbial communities could be influencing the level of anti-microbial activity of deposited egg masses, suggesting that these differences may play a role in oviposition preference of H. vesicula adults.