Microbes and Environments
Online ISSN : 1347-4405
Print ISSN : 1342-6311
ISSN-L : 1342-6311
Regular Papers
Molecular Detection of Eukaryotic Diets and Gut Mycobiomes in Two Marine Sediment-Dwelling Worms, Sipunculus nudus and Urechis unicinctus
Yaping WangTiantian ShiGuoqiang HuangJun Gong
Author information
Supplementary material

2018 Volume 33 Issue 3 Pages 290-300


The present study aimed to reveal the eukaryotic diets of two economically important marine sediment-inhabiting worms, Sipunculus nudus (peanut worm) and Urechis unicinctus (spoon worm), using clone libraries and phylogenetic analyses of 18S rRNA genes. Fungal rDNA was also targeted and analyzed to reveal mycobiomes. Overall, we detected a wide range of eukaryotic phylotypes associated with the larvae of S. nudus and in the gut contents of both worms. These phylotypes included ciliates, diatoms, dinoflagellates, eustigmatophytes, placidids, oomycetes, fungi, nematodes, flatworms, seaweeds, and higher plants. Oomycetes were associated with the planktonic larvae of S. nudus. The composition of eukaryotic diets shifted greatly across the larval, juvenile, and adult stages of S. nudus, and among different gut sections in U. unicinctus, reflecting lifestyle changes during the ontogeny of the peanut worm and progressive digestion in the spoon worm. Malassezia-like fungi were prevalent in mycobiomes. Epicoccum and Trichosporon-related phylotypes dominated mycobiomes associated with larval individuals and in the gut contents of adults, respectively. The gut mycobiome of S. nudus was successively characterized through the midgut, aspiratory intestines, hindgut, and rectum as having a high proportion of Climacodon-Rhizochaete, Ceriporiopsis, Cladosporium-Pseudomicrostroma, and Malassezia-related species in the libraries. These results emphasize the dynamics of diets and gut mycobiomes in marine benthic animals.

Related papers from these authors
© 2018 by Japanese Society of Microbial Ecology / Japanese Society of Soil Microbiology / Taiwan Society of Microbial Ecology / Japanese Society of Plant Microbe Interactions.
Previous article Next article