THE REPRODUCTIVE SYSTEM OF CHONDRIA TUMULOSA: THE PAPAHĀNAUMOKUĀKEA MARINE NATIONAL MONUMENT’S FIRST KNOWN NUISANCE ALGA
| dc.contributor.author | Williams, Taylor M. | |
| dc.date.accessioned | 2023-05-01T13:08:27Z | |
| dc.date.available | 2023-05-01T13:08:27Z | |
| dc.date.updated | 2023-05-01T13:08:31Z | |
| dc.description.abstract | The Northwestern Hawaiian Islands are a 1,931 km chain of remote and nearly pristine atolls within the Papahānaumokuākea Marine National Monument. Chondria tumulosa is a highly abundant, mat-forming rhodophyte and the first recorded invasive-like macroalga in Papahānaumokuākea. It was observed in low abundance at Manawai (Pearl and Hermes Atoll) in 2015, but by 2019, formed large mats that smothered native corals and algae, reducing biodiversity and abundance of reef organisms on the scale of thousands of m2. I hypothesize that the rapid establishment of C. tumulosa is aided by its capacity for asexual reproduction via vegetative fragmentation, a reproductive mode that has been shown to facilitate other macroalgal invasions. Reproductive systems encompass the relative contribution of sexual and asexual reproduction to a population and play a central role in the partitioning of genetic diversity. Based on microscopic observations, thalli were mostly vegetative, but all reproductive thalli (~20%) were tetrasporophytes at the time of sampling. Since population genetic analyses are required to study the reproductive system, I developed microsatellite loci, five of which were used to genotype 41 thalli. We found 27 unique multilocus genotypes, all of which were diploid tetrasporophytes. Chondria tumulosa gametophytes were not observed at Manawai. Single-locus FIS values were largely negative, suggesting vegetative thallus fragmentation. However, the large variance in FIS values (Var[FIS] = 0.490) aligns with what is expected in partially clonal populations. The low Pareto ß value (0.729) at Manawai suggests high rates of clonality that remain to be tested, however the low linkage disequilibrium (〖r̄〗_d = 0.062) suggested that some recombination has been maintained which is consistent with the tetraspores found via microscopy. These data will aid in the development of best management practices pertaining to invasive macroalgae and will progress our understanding of the evolutionary maintenance of sex. | |
| dc.identifier.uri | https://repository.library.cofc.edu/handle/123456789/5452 | |
| dc.language.rfc3066 | en | |
| dc.title | THE REPRODUCTIVE SYSTEM OF CHONDRIA TUMULOSA: THE PAPAHĀNAUMOKUĀKEA MARINE NATIONAL MONUMENT’S FIRST KNOWN NUISANCE ALGA | |
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