Genetic structure and diversity of the endangered bath sponge Spongia lamella

Abstract

ABSTRACT1. Natural populations of Mediterranean commercial sponges have declined substantially over recent decades. 2. The present study explored the distribution of genetic diversity of the endangered bath sponge Spongia lamella along the western Mediterranean and the Portuguese coast.3. Seven microsatellite markers were used to genotype 231 individuals scattered over nine populations. Basic genetic descriptors and population genetic analyses based on F ST test, analyses of the molecular variance (AMOVA), Bayesian clustering, dissimilarity analysis of principal components, and demographic analyses were performed.4. Genetic differentiation between populations was large and highly significant (global F ST = 0.236, P < 0.001). AMOVA and Bayesian analyses showed genetic differentiation among the Atlantic, Balearic, and North Mediterranean areas (F CT = 0.129, P = 0.003).5. Restricted gene flow owing to short-distance larval dispersal and hydrographical barriers may be playing an important role in genetic differentiation.6. Recent bottlenecks were also detected for most populations of this sponge. 7. The high levels of inbreeding, sub-structuring, and modest levels of genetic diversity that characterized populations of S. lamella (mean value of genetic diversity 0.512), may compromise its long-term survival. Only one population, from the Gibraltar Strait, presented high levels of genetic diversity (Ceuta, genetic diversity = 0.657), indicating a hotspot of genetic diversity for this species with special relevance for its conservation.8. Disease outbreaks and overexploitation may be the most important causes of genetic diversity impoverishment of S. lamella.9. Future conservation guidelines should focus on preserving genetic diversity within genetically impoverished populations by limiting exploitation, and increasing population size. Transplanting specimens from areas with high values of genetic diversity to areas with low diversity values or to areas that have recently experienced demographic declines could reverse the local and global recession of this species.

Population substructure and signals of divergent adaptive selection despite admixture in the sponge Dendrilla antarctica from shallow waters surrounding the Antarctic Peninsula

“…Furthermore, the strong oceanic currents in the study area (Moffat, Beardsley, Owens, & Van Lipzig, ; Zhou, Niiler, & Hu, ; see Figure b) may increase the dispersal ability of D. antarctica larvae. Remarkably, our results differ from most previous population genetic studies on sponges, which generally report highly structured and differentiated populations, even at local and regional scales (e.g., Brown et al, ; DeBiasse et al, ; Pérez‐Portela, Noyer, & Becerro, ; Riesgo et al, ). Even compared to some oviparous sponges such as Cliona delitrix which appears to disperse along the ~315 km of the Florida reef track (Chaves‐Fonnegra, Feldheim, Secord, & Lopez, ), our results suggested an unprecedent ~900 km contemporary migration.…”

Implications of population connectivity studies for the design of marine protected areas in the deep sea: An example of a demosponge from the Clarion‐Clipperton Zone

“…Plenaster craigi (this study); 9. Spongia lamella (Pérez‐Portela et al., ); 10. Crambe crambe (Duran et al., ); 11.…”

“…This suggests that sponge recolonization following large‐scale mining disturbance in the UK‐1 and OMS contract areas may be slow due to the limitations of larval dispersal. For sponges, low migration levels between populations are not rare, since very few migrants are usually reported among locations (Riesgo et al., ), and this pattern is also shared with other sessile invertebrates (Pérez‐Portela et al., ). By contrast, a deep sea amphipod species of the genus Paralicella displayed a remarkably high and reciprocal Pan‐Pacific migration between hadal trench populations (Ritchie et al., ).…”

“…The genetic diversity values found in our study are within the range of other studies on marine sponges using microsatellite markers. Comparisons with data available in these studies (Duran, Pascual, Estoup, & Turon, 2004;Blanquer, Uriz, & Caujapé-Castells, 2009;Blanquer & Uriz, 2010;Dailianis, Tsigenopoulos, Dounas, & Voultsiadou, 2011;Guardiola, Frotscher, & Uriz, 2012, 2016Bell et al, 2014;Pérez-Portela, Noyer, & Becerro, 2015;Giles, Saenz-Agudelo, Hussey, Ravasi, & Berumen, 2015;Chaves-Fonnegra, Feldheim, Secord, & Lopez, 2015;Riesgo et al, 2016;under…”

Shared phylogeographical breaks in a Caribbean coral reef sponge and its invertebrate commensals

“…Data from COI and six nuclear markers showed significant population subdivision in C. vaginalis . These patterns are consistent with previous sponge studies employing a variety of markers, which often attribute genetic differentiation to limited larval dispersal (Blanquer et al ., ; López‐Legentil & Pawlik, ; Blanquer & Uriz, ; Dailianis et al ., ; Pérez‐Portela et al ., ; Chaves‐Fonnegra et al ., ). Our previous work on C. vaginalis in Florida at a smaller spatial scale showed genomically discordant patterns of structure: COI haplotypes were geographically subdivided, while nuclear alleles were panmictic (DeBiasse et al ., , ).…”