Sponge diversification in marine lakes: Implications for phylogeography and population genomic studies on sponges. Issue 4 (13th April 2023)

• Record Type: Journal Article
• Authors: Maas, Diede L.; Prost, Stefan; de Leeuw, Christiaan A.; Bi, Ke; Smith, Lydia L.; Purwanto, Purwanto; Aji, Ludi P.; Tapilatu, Ricardo F.; Gillespie, Rosemary G.; Becking, Leontine E.
• Is Part Of: Ecology and evolution. Volume 13:Issue 4(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-04-13
• Subjects: genetic resolution -- marine biodiversity -- Porifera -- RADseq -- seascape genomics -- Suberites diversicolor; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.9945
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: The relative influence of geography, currents, and environment on gene flow within sessile marine species remains an open question. Detecting subtle genetic differentiation at small scales is challenging in benthic populations due to large effective population sizes, general lack of resolution in genetic markers, and because barriers to dispersal often remain elusive. Marine lakes can circumvent confounding factors by providing discrete and replicated ecosystems. Using high‐resolution double digest restriction‐site‐associated DNA sequencing (4826 Single Nucleotide Polymorphisms, SNPs), we genotyped populations of the sponge Suberites diversicolor ( n = 125) to test the relative importance of spatial scales (1–1400 km), local environmental conditions, and permeability of seascape barriers in shaping population genomic structure. With the SNP dataset, we show strong intralineage population structure, even at scales <10 km (average F ST = 0.63), which was not detected previously using single markers. Most variation was explained by differentiation between populations (AMOVA: 48.8%) with signatures of population size declines and bottlenecks per lake. Although the populations were strongly structured, we did not detect significant effects of geographic distance, local environments, or degree of connection to the sea on population structure, suggesting mechanisms such as founder events with subsequent priority effects may be at play. We show that the inclusion of morphologically cryptic lineages that can be detected with the COI marker can reduce the obtained SNP set by around 90%. Future work on sponge genomics should confirm that only one lineage is included. Our results call for a reassessment of poorly dispersing benthic organisms that were previously assumed to be highly connected based on low‐resolution markers. Abstract : High‐resolution genotyping of the marine sponge Suberites diversicolor from marine lakes confirms genetic lineages, but provides new evidence for strong intralineage population structure. Geographic distance and local environments did not explain genetic differentiation, suggesting other mechanisms such as founder events with priority effects may be at play. Results indicate the potential need to reassess panmictic assumptions from poorly dispersing benthic organisms.