Population connectivity of fan-shaped sponge holobionts in the deep Cantabrian Sea

• Published in: Deep Sea Research Part I: Oceanographic Research Papers
• Main Authors: Busch, Kathrin, Taboada, Sergi, Riesgo, Ana, Koutsouveli, Vasiliki, Ríos, Pilar, Cristobo, Javier, Franke, Andre, Getzlaff, Klaus, Schmidt, Christina, Biastoch, Arne, Hentschel, Ute
• Format: Report
• Language: unknown
• Published: 2020
• Subjects: Porifera; Population genetics; Single-nucleotide polymorphisms (SNPs); Amplicon sequencing; Lagrangian modelling; Ocean sensing; European Union (EU); Horizon 2020; Deep-sea Sponge Grounds Ecosystems of the North Atlantic: an Integrated approach towards their preservation and sustainable exploitation; SponGES; Grant Agreement No 679849; Rath; North Atlantic
• Online Access: https://zenodo.org/record/4290746; https://doi.org/10.1016/j.dsr.2020.103427

ABSTRACT Connectivity is a fundamental process driving the persistence of marine populations and their adaptation potential in response to environmental change. In this study, we analysed the population genetics of two morphologically highly similar deep-sea sponge clades (Phakellia hirondellei and the ‘Topsentia-and-Petromica’ clade, (hereafter referred to as ‘TaP clade’)) at three locations in the Cantabrian Sea and simultaneously assessed the corresponding host microbiome by 16S rRNA gene sequencing. A virtual particle tracking approach (Lagrangian modelling) was applied to assess oceanographic connectivity in the study area. We observed overall genetic uniformity for both sponge clades. Notably, subtle genetic differences were observed for sponges of the TaP clade and also their microbiomes between a canyon and bank location, < 100 km apart and with the same depth range. The Lagrangian model output suggests a strong retention of larvae in the study area with variable inter-annual connectivity via currents between the three sampling regions. We conclude that geologic features (canyons) and the prevailing ocean currents may dictate sponge holobiont connectivity and that differentiation can emerge even on small spatial scales. ABBREVIATIONS TaP cladeTopsentia-and-Petromica clade ACKNOWLEDGEMENTS We dedicate this study to Hans Tore Rapp, friend, mentor and esteemed colleague whose outstanding expertise in deep-sea sponge taxonomy will be dearly missed. We greatly acknowledge the crew and scientific party of RV Ángeles Alvariño cruise SponGES0617 for their valuable support at sea. As well as members of the IEO Gijón for logistical support during a guest stay of KB before the cruise. We appreciate Andrea Hethke's and Ina Clefsen's, as well as Thomas Hansen's assistance in the laboratory after the cruise while generating the microbial amplicon and flow cytometry data. We thank Willi Rath for support in technical issues with the modelling part, and Lara Schmittmann and Ina Clefsen for technical support with 18S ...