Actually, it is also called "coco-fesses" in French (which literally means "butt coconut"). We have one in the family, with some suggestive fibers, very similar to the picture below (source: lodoiceamaldivica.wordpress.com/cocofesse/)

How many bacteria are in these organs? We performed qPCR and normalized by cell number (organs, whole snails) or volume (hemolymph, water). The digestive system (stomach and gut) showed the highest density, while levels were more variable in the hepatopancreas and low in the ovotestis.

How are these taxa shared between organs? They are mostly sample-type specific, especially in the hemolymph and ovotestis. Hemolymph and whole snail share the most taxa. Some taxa are snail-specific, suggesting internal conditions favor them, while others are found in snails and water.

Taxonomic diversity revealed a surprising number of unknown taxa in the hepatopancreas and ovotestis. These organ microbiomes warrant further study to characterize these mysterious taxa. Taxonomic diversity of the whole snail microbiomes was similar to the hemolymph microbiome diversity.

These organ microbiomes were different from the hemolymph, specific, and either linked by physical proximity or functionnality, depending on the beta-diversity metrics used. The whole snail microbiome was consistently close to the hemolymph microbiome.

Organs harbored microbiomes with varying microbial diversity. Hemolymph showed the highest alpha-diversity, similar to the whole snail microbiome. Sample type (organs and hemolymph) was the primary factor explaining microbial diversity before the snail species.

We chose stomach/gut (commonly studied), hepatopancreas (liver), and ovotestis (targeted by schistosomes 🪱) from uninfected snails of 2 Biomphalaria species. We also analyzed whole-snail 🐌 microbiomes (commonly studied) to test if they truly reflect the composite of individual organ microbiomes.