Gut Microbial Composition and Diversity in Four Ophiuroid Species: Divergence Between Suspension Feeder and Scavenger and Their Symbiotic Microbes

Abstract

Gut microbiota have important roles in the survival and adaptation of the host. Ophiuroids, as the worldwide dominant benthos, have ecological roles in benthic–pelagic coupling in the sea floor. However, little is known about the composition and diversity of their gut microbiota and its potential functions in benthic ecosystems. In present study, we preformed 16S rRNA sequencing and function analysis in four dominant species (Stegophiura sladeni, Ophiopholis mirabilis, Ophiura sarsii vadicola, and Ophiura kinbergi) with two feeding types (suspension feeding/herbivores and scavenger/carnivores) from the Yellow Sea, China. Results showed that 56 phyla and 569 genera of microbiota were identified among ophiuroid guts. Multivariate and diversity analyses showed that the ophiuroid gut microbiota were independent and have higher biodiversity to the sediment microbial in the Yellow Sea. Phyla Proteobacteria, Firmicutes, Tenericutes, and Bacteroidetes were the dominant bacteria, with more than 80% abundance among the four ophiuroid species. A comparison among the gut microbial compositions among four ophiuroids showed the similarity of two offshore carnivore ophiuroids (S. sladeni and O. sarsii vadicola) and variation in the dominant microbiota types of three nearshore ophiuroids (S. sladeni, O. mirabilis, and O. kinbergi). The functional analysis revealed the significant differences of the environment-related expression in S. sladeni gut microbiota between nearshore and offshore environments. The Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) functional annotation showed the significant divergence of metabolism pathways between two nearshore species, the herbivores O. mirabilis and carnivores S. sladeni, such as the Lipid metabolism, Carbohydrate metabolism, and Metabolism of cofactors and vitamins. The homolog search and phylogenetic analysis identified the first gut symbiotic Candidatus Hepatoplasma in S. sladeni with important roles for the nutrient metabolisms. Overall, our study reported the comprehensive data of ophiuroid gut microbiota, while the functional microbiome provides insight into the physiology and environmental adaptation in ophiuroids.

Reshaping fish intestinal microbiota and facilitating barrier function by ZnO nanoparticles

“…In this study, the significantly accumulated Zn concentration in the intestine illustrated that 60 mg Zn kg −1 of dietary nZnO released more Zn than ZnSO 4 in the fish body, thus providing the physiological functions in fish. 15,23 The core microorganisms identified in our study were the same species commonly found in other fish, [27][28][29] but there were differences in species abundance. The most abundant microorganisms (Photobacterium and Mycoplasma) colonized in the 60 mg Zn kg −1 ZnSO 4 exposure group carried out the metabolic activities of nutrients (glucose, lipid and protein) through the reductive citrate cycle (Arnon-Buchanan cycle) pathway, and then efficiently produced ATP through oxidative phosphorylation.…”

Distinct gut microbial communities and functional predictions in divergent ophiuroid species: host differentiation, ecological niches, and adaptation to cold-water habitats

“…The sequences were clustered into three clades. Both Clade I and Clade II contained reference sequences from Dong et al ( 28 ). Clade I was mainly a group of O. sarsii in Funka Bay and O. sarsii vadicola in the Yellow Sea (SJP and SSYS).…”

“…Clade I was the aggregation of groups SBL and SSYS. Clade II contained a variety of sequences, including those ASVs from groups SBL and SSYS, shared ASV sequences, and reference sequences from Dong et al ( 28 ).…”

“…The microbial community structure and predictive function in the gut of ophiuroids have been studied extensively in the Yellow Sea. The study reported two feeding types—suspension feeding/herbivores and scavenger/carnivores—and their respective microbial communities, providing insights into the complex interactions between the host and their gut microbiota ( 28 ).…”

Host habitat shapes the core gut bacteria of decapod crustaceans: A meta-analysis

“…Similarly, ZR0006, a Firmicutes (12.4% in spiny lobster, 0.6% in European lobster) differentiates the gut microbiota of two lobster species. Candidatus are novel lineages of Mollicutes, abundant only in the gut of crustaceans [ 18 , 20 , [71] , [72] , [73] ] and other invertebrate species [ 74 , 75 ] while very rare in vertebrate animals. As a core gut microbiota, they play a positive role in the health and immunity of marron, a freshwater crayfish species native to Western Australia [ 18 , 76 ].…”