Morphological and Molecular Analyses of Microorganisms in Caribbean Reef Adult Sponges and in Corresponding Reproductive Material

Caribbean reef sponges were surveyed for the presence of microorganisms in the mesohyl tissue of adult sponges and the respective reproductive material (embryos, larvae). A clear correlation was found in that high microbial abundance (HMA) sponges always contained microorganisms in their reproductive stages. In contrast, low microbial abundance (LMA) sponges did not contain microorganisms in their reproductive stages. Based on these data, Ircinia felix Duchassaing and Michelotti, 1864 was chosen as a model organism for the molecular analysis of microorganisms within the adult sponge and its larvae and juveniles. Denaturing gradient gel electrophoresis (DGGE) of eubacterial 16S rDNA sequences revealed similar banding patterns for the adult individual and its reproductive stages. However, resolution of the DGGE gel was found to be limited. Selected DGGE bands (n=21) were excised and sequenced. The majority of sequences were most similar to sequences obtained from other HMA sponges indicating the presence of members of the previously identified, sponge-specific community in the adult sponge and its reproductive stages