Microbiomes of the polychaete Hydroides elegans (Polychaeta: Serpulidae) across its life-history stages
Larvae of the biofouling tubeworm Hydroides elegans (Polychaeta) must contact a bacterial biofilm to induce settlement. To further understand the relationship between particular bacteria and the worm, this study analyzed associated microbiomes at multiple life-history stages with high-throughput 16S rRNA amplicon sequencing. Worms were collected from Pearl Harbor Hawai’i (21°21′27.2″N 157°57′34.8″W), and microbial communities were analyzed from adults, their tubes, spawned eggs, 6-day old nectochaete larvae, and filtered seawater from the larval cultures that included cells of the microalga Isochrysis galbana fed to the larvae. Microbiomes of females sampled at two different times were significantly different: Cellvibrionales dominated the microbiome of adult females in August 2016, whereas Oceanospirillales were dominant in females collected in April 2017. Additionally, in 2017, the microbiomes across all life stages were significantly different from each other; only one OTU in the genus Endozoicomonas was shared between females and their nectochaetes at a relative abundance > 1%. Because of the apparent absence of a consistent microbiome between stages, female worms, their eggs and both trochophore and nectochaete larvae were stained to reveal the presence of bacteria and analyzed with scanning confocal microscopy. The eggs were almost devoid of bacteria, and bacteria seen on larvae were almost all confined to the feeding apparatus. The evidence of inconsistent microbiomes across life stages and lack of bacteria on eggs demonstrates that H. elegans lacks a vertically transmitted microbiome, and bacteria found at each stage came from a varying environment.
KeywordsPolychaete Hydroides elegans Life stages Microbiome 16S rRNA
We are pleased to acknowledge lab assistants Kenneth Choi and Krystel Sarvis for assisting in culturing larvae. Dr. Marnie Freckelton provided very useful commentary and assistance on earlier drafts of this manuscript. The authors are grateful to the reviewers for their constructive comments and recommendations. This is publication number 10576 from the School of Ocean, and Earth Science and Technology and the Kewalo Marine Laboratory at the University of Hawai’i at Mānoa.
Research reported here was supported by funds from grants to MGH from the Oak Foundation (no. ORIO-13-013) and to MGH and BN from the Gordon and Betty Moore Foundation (no. 5009), and U.S. Office of Naval Research Grant no. N00014-15-1-2658.
Compliance with ethical standards
Conflict of interest
All authors declare that they have no conflict of interests.
All applicable international, national, and/or institutional guidelines for the care and use of animals were followed.
- Hadfield MG (2011) Biofilms and marine invertebrate larvae: what bacteria produce that larvae use to choose settlement sites. Annu Rev Mar Sci 3:453–470. https://doi.org/10.1146/annurev-marine-120709-142753 CrossRefGoogle Scholar
- Hadfield MG, Unabia C, Smith CM, Michael TM (1994) Settlement preferences of the ubiquitous fouler Hydroides elegans. In: M. Fingerman, R. Nagabhushanam, R. Sarojini (eds) Recent developments in biofouling control. Oxford & IBH, New Delhi, pp. 65-74Google Scholar
- Hadfield MG, Unabia C, Smith CM, Michael TM (1994b) Settlement preferences of the ubiquitous fouler Hydroides elegans. In: Fingerman M, Nagabhushanam R, Sarojini R (eds) Recent developments in biofouling control. Oxford & IBH, New Delhi, pp 65–74Google Scholar
- Lema KA, Constancias F, Rice SA, Hadfield MG (2019) High bacterial diversity in near-shore and oceanic biofilms and their influence on larval settlement by Hydroides elegans (Polychaeta) (submitted)Google Scholar
- Neave MJ, Streten-Joyce C, Glasby CJ, McGuinness KA, Parry DL, Gibb KS (2012) The bacterial community associated with the marine polychaete Ophelina sp. 1 (Annelida: Opheliidae) is altered by copper and zinc contamination in sediments. Micro Ecol 63:639–650. https://doi.org/10.1007/s00248-011-9966-9 CrossRefGoogle Scholar
- Oliveros J (2017) Venny. An interactive tool for comparing lists with Venn’s diagrams. http://bioinfogp.cnb.csic.es/tools/venny/index.htm
- Ruehland C, Blazejak A, Lott C, Loy A, Erséus C, Dubilier N (2008) Multiple bacterial symbionts in two species of co-occurring gutless oligochaete worms from Mediterranean sea grass sediments. Environ Microbiol 10:3404–3416. https://doi.org/10.1111/j.1462-2920.2008.01728.x CrossRefPubMedGoogle Scholar
- Walters W (2016). Improved bacterial 16S rRNA gene (V4 and V4–5) and fungal internal transcribed spacer marker gene primers for microbial community surveys. mSystems 1:e00009–00015. https://doi.org/10.1128/msystems.00009-15
- Weiland-Bräuer N, Neulinger SC, Pinnow N, Künzel S, Baines JF, Schmitz RA (2015) Composition of bacterial communities associated with Aurelia aurita changes with compartment, life stage, and population. Appl Environ Microbiol 81:6038–6052. https://doi.org/10.1128/AEM.01601-15 CrossRefPubMedPubMedCentralGoogle Scholar