Pairwise comparisons between individual bacterial genera from the core digestive microbiota (Fig. 4) and contextual parameters showed specific ecological patterns. The genera Psychrilyobacter, an unclassified Flavobacteriaceae, and Ulvibacter followed similar patterns. They increased in relative OTU abundances with a decreasing content in mostly the same algal biochemical compounds and with increasing abalone digestive gland weight. Mycoplasma also showed similar patterns related to abalone characteristics. OTU proportions of Vibrio, Psychromonas, an unclassified Rhodobacteraceae, Polaribacter, and Pseudahrensia likely increased with increasing temperature and no significant relationships were found with other parameters (Fig. 5).Fig. 5Pairwise comparison between genera of the core microbiota and contextual parameters. Pairwise comparisons were measured by Spearman correlation. The core microbial genera were ordered according to sequence read abundance; with Psychrilyobacter being the most abundant group. The strength of the correlation is indicated by a heatmap colored from red to blue. The horizontal axis corresponds to sampling dates, temperature, abalone characteristics and algal diet composition. Only significant correlations after application of the Benjamini-Hochberg correction for multiple testing were represented. GDG, gonado-digestive gland; DG, digestive gland; G, gonad. Unc, unclassified