LE3 .A278 2020

2020

Easy, Russell
Stewart, Don

Acadia University

Bachelor or Science

Honours

Biology

Biology

Three groups of morphologically distinct freshwater mussels (Family: Unionidae) were collected near Cañas, Guanacaste, Costa Rica. Two of these three putative species are the focus of this thesis. These species are of interest in terms of (1) documenting the biodiversity of Costa Rica, and (2) because many freshwater mussels exhibit an unusual form of mitochondrial DNA transmission known as doubly uniparental inheritance (DUI). DNA samples from fourteen individuals were extracted, PCR-amplified and sequenced using universal cytochrome oxidase subunit I primers. The results revealed invasive species Sinanodonta woodiana (Chinese pond mussel), and two unionid species that share ~93% and ~89% sequence similarity to native Mesoamerican species Psorula profunda and Anodontites trigonus, respectively. Morphology and recent developments in Mesoamerican unionid phylogenetics suggest that the P. profunda relative is possibly in the genus Nephronaias, which is undescribed on molecular databases, such as GenBank. To assist in identification, phylogenetic trees were constructed, and results compared with previously published phylogenies. DUI was detected in putative Nephronaias sp. using primers that only amplify a gene region specific to the male transmitted mitochondrial genomes in DUI positive species. The establishment of S. woodiana in Guanacaste and surrounding regions can be attributed to the unusual glochidial life stage of unionids. Phylogenetic relationships, DUI, and the biology of invasive species are all critical aspects to consider in biodiversity conservation of freshwater mussels –an understudied field in Mesoamerica.

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https://scholar.acadiau.ca/islandora/object/theses:3460