3 páginas, 1 tabla. ; The gorgonian Paramuricea clavatais a benthic organism often included in conservation management plans since it creates complexity in the ecosystems and is extremely vulnerable to disturbances. Eight microsatellite markers isolated from an enriched genomic library were characterized in a total of 50 individuals from two northwestern Mediterranean populations. All loci were polymorphic and the number of alleles per locus ranged between 2 and 14. Significant genetic differentiation was observed between populations. The polymorphic markers presently isolated will allow for the assessment of the spatial genetic structure between and within populations of this umbrella species of the Mediterranean Sea. ; This research was supported by projects 119/2003 and CTM2007-66635 (CICYT) from the Spanish Government. ; Peer reviewed
Este artículo contiene 9 páginas, 2 tablas, 1 figura ; Antarctic bottoms harbor stable, benthic communities, subjected to low temperatures. Environmental stability may promote the asexual (clonal) reproduction of sponges to maintain adapted genotypes to those particular conditions. Stylocordyla chupachups forms patchy populations across the Antarctic continental shelf. Individuals are mostly similar in size without distinct cohorts, which indicates fast growth of the new recruits. Settlement of incubated (clonal?) functional sponges may accelerate sponge growth and success at early colonization phases. To analyze the weight of clonal reproduction in the species, a genetic study was performed on three close populations using eight polymorphic microsatellite loci that were designed from massive sequencing. The three study populations showed a relatively low genetic diversity and low loci polymorphism (from 2 to 6 alleles). The estimators of genetic structure, the Analysis of the Molecular Variance (AMOVA), and the presence of private alleles indicated low but significant structure between the populations. A relatively high rate of asexual reproduction (ca. 25% of the individuals) was detected. The program MLGsim found five identical multilocus genotypes (MLGs) with an asexual origin. An excess of heterozygotes (in five out of the eight loci genotyped) was found, which suggests a positive selection mechanism for heterozygotes. The relatively high rates of asexual reproduction may be the result of adaptation to the environmental stability, while heterozygote selection would help maintain some genetic diversity in the populations. S. chupachups has been reported to be one of the first sponge species recolonizing bare areas resulting from iceberg scouring, which indicates a high species fitness and adaptation to Antarctic bottoms. Two out of the three study populations showed bottleneck, which may indicate a recent founder effect and supports the pioneer nature of this species. ; The study has been partially funded by MarSymBiomics project (Spanish FECYT agency grant ref. CTM2013-43286-P), Benthic Ecology Consolidate Award (Generalitat of Catalonian ref. 2017SGR-378), PopComics (CTM88080AEI/FEDER/VE) from the Spanish Government, and BluePharmTrain FP7 People-INT no: 607786 to MJU. ; Peer reviewed
7 páginas, 9 figuras. ; Marine biodiversity is difficult to assess accurately in part because of the existence of sibling species, which are difficult to discern. This is particularly tricky when sibling species live in sympatry. We investigated biological and ecological traits in 2 sympatric sibling sponge species inhabiting the shallow north-western Mediterranean: Scopalina lophyropoda Schmidt, 1862 and S. blanensis Blanquer & Uriz, 2008. Growth, fissions, fusions, and survival were monitored twice monthly for 2 yr. S. lophyropoda slightly increased in area over the 2 yr period, whereas S. blanensis did not show effective growth, since gains in autumn to winter were offset by losses in spring to summer. Survival was significantly different in both species. By the end of the study (24 mo), 74% of the individuals of S. lophyropoda and 34% of S. blanensis survived. All individuals of S. lophyropoda and all but 5 of S. blanensis underwent fissions or fusions at least once during the study. The frequencies of multiple fissions and fusions were higher in S. blanensis than in S. lophyropoda. These 2 sympatric sibling species share common traits such as a high dynamism (higher than any other previously studied encrusting sponge species) and intra-species variability in growth. However, they showed contrasting ecological strategies (conservative in S. lophyropoda vs. opportunistic in S. blanensis), which favours species coexistence. This example shows for the first time how seasonality promotes the co-existence of sibling sponge species in the Mediterranean, and may represent an important step towards understanding species coexistence mechanisms. ; This study was funded by grants INTERGEN CTM2004- 05265-C02-02/MAR and MARMOL CMT2007-66635-C02 from the Spanish Government (CICYT) to M.J.U. and an I3P fellowship to A.B. ; Peer reviewed
4 páginas, 1 tabla. ; The abundance of the bath sponge Spongia agaricinahas decreased drastically in recent years and it is now considered an endangered species under Annex 3 of Bern and Barcelona conventions. We describe eight microsatellite markers and present data on their allelic variation and utility as high resolution genetic markers. We analyzed 36 individuals from two populations and found that the number of alleles per locus ranged between 1 and 7. Observed heterozygosity ranged from 0 to 0.72. We found deviations from Hardy–Weinberg expectations for some loci. We exclusively detected null alleles for those loci that deviated from Hardy–Weinberg expectations. Also, distributions of allele frequencies differed significantly between the two populations, making them suitable for population genetic analyses. ; Research funded by grants from the Agencia Nationale de la Recherche (ECIMAR), Spanish Ministry of Environment (119/2003), Spanish Ministry of Education and Science (CMT2007-66635) and the BIOCAPITAL project (MRTN-CT-2004- 512301) of the European Union. ; Peer reviewed
