Biology subjects

Muffett, K. M.

Publications and source records attributed to Muffett, K. M..

3 recordsLinked to original sources

bioRxiv2025

Low-abundance taxa drive host microbiome response to temperature stress

Global climate change (GCC) will lead to the deterioration of host and microbiome health, posing a significant threat to complex symbioses. To gauge the reproducibility of thermal warming associated with GCC and the time scales on which it occurs, we monitored shifts in the Exaiptasia microbiome in 24 populations of the model cnidarian Exaiptasia diaphana over the course of six months. We identified a small cohort of temperature-sensitive amplicon sequence variants (ASVs) that reproducibly declined with increases in temperature before changes in host fitness occurred. After comparing these ASVs to global datasets, we found that the heat-impacted ASVs from our experiment were also present in many other cnidarian species, highlighting their potential as widespread indicators of thermal stress. Overall, we find that fewer than 1% of the microbiome within E. diaphana are heat indicator taxa, suggesting that a small but consistent group of ASVs signals the early stages of thermal stress.

ecology↗

bioRxiv2025

Notes on the diet and size of Cassiopea

Medusae of the genus Cassiopea are common components of tropical and subtropical coastlines globally. Despite the broad distribution of this benthic scyphozoan, much about their ecology remains poorly described. Here, we collected over 100 adult Cassiopea individuals from Panama, the eastern United States, Cuba, the Philippines, Italy and Australia to examine continuity and differences in their diet across space, and to investigate whether their unique lifestyle is reflected in their diet. We found the majority of prey items to be associated with the epibenthos. The recovered prey were supermajority crustaceans, mainly harpacticoid copepods, with pteropods, nematodes, and miscellaneous eggs common as secondary components. Within the gastrovascular cavity of a single medusa, we found up to 379 items. There was a limited relationship between medusa size and prey items. Location had an impact on gut content diversity and medusa size had a small impact on the number of taxa found within the gut. In some sites, prey were scarce or absent from all medusae sampled. Overall, we reaffirm the diet previously recorded for small medusae in Puerto Rico and show that similar components are common in large and small medusae from throughout the East and West Atlantic and the Philippines.

ecology↗

bioRxiv2024

Bacterial communities of Cassiopea in the Florida Keys share major bacterial taxa with coral microbiomes

Interactions with microbial communities fundamentally shape metazoans physiology, development, and health across marine ecosystems. This is especially true in zooxanthellate (symbiotic algae-containing) cnidarians. In photosymbiotic anthozoans (eg. shallow water anemones and corals), the key members of the associated microbiota are increasingly well studied, however there is limited data on photosymbiotic scyphozoans (true jellyfish). Using 16S rRNA barcoding, we sampled the internal and external mucus of the zooxanthellate Upside- Down Jellyfish, Cassiopea xamachana throughout eight sites covering the full length of the Florida Keys. We find that across sites, these medusae to have low-diversity internal microbial communities distinct from the communities of their external surfaces and their environment. These internal communities are dominated by only three taxa: Endozoicomonas cf. atrinae, an uncultured novel Mycoplasma, and Vibrio cf. coralliilyticus. Cassiopea bell mucosal samples conform largely to the communities of surrounding sediment with the addition of Endozoicomonas cf. atrinae. The microbial taxa we identify associated with wild Florida Keys Cassiopea bear a strong resemblance to those found within photosymbiotic anthozoans, increasing the known links in ecological position between these groups.

ecology↗