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Full-Text Articles in Life Sciences

Genetic Analyses Determine Connectivity Among Cave And Surface Populations Of The Jamaican Endemic Freshwater Crab Sesarma Fossarum In The Cockpit Country, Manuel Stemmer, Christoph D. Schubart Nov 2015

Genetic Analyses Determine Connectivity Among Cave And Surface Populations Of The Jamaican Endemic Freshwater Crab Sesarma Fossarum In The Cockpit Country, Manuel Stemmer, Christoph D. Schubart

International Journal of Speleology

The Jamaican freshwater crab Sesarma fossarum (Decapoda: Brachyura: Sesarmidae) is endemic to western central Jamaica where it occurs in cave and surface streams of karst regions. In the present study, we examine the population genetic structure of the species, providing evidence for intraspecific differentiation and genetic substructure among twelve sampled populations. Interestingly, crabs from caves appear genetically undistinguishable from representatives of nearby surface waters, despite previously observed and described morphometric differentiation. In contrast, genetic isolation takes place among populations from rivers and caves belonging to different watersheds. In one case, even populations from different tributaries of the same river were …


A Decline In Benthic Foraminifera Following The Deepwater Horizon Event In The Northeastern Gulf Of Mexico, Patrick Schwing, Isabel C. Romero, Gregg R Brooks, David W Hastings, Rebekka A Larson, David Hollander Mar 2015

A Decline In Benthic Foraminifera Following The Deepwater Horizon Event In The Northeastern Gulf Of Mexico, Patrick Schwing, Isabel C. Romero, Gregg R Brooks, David W Hastings, Rebekka A Larson, David Hollander

Marine Science Faculty Publications

Sediment cores were collected from three sites (1000-1200 m water depth) in the northeastern Gulf of Mexico from December 2010 to June 2011 to assess changes in benthic foraminiferal density related to the Deepwater Horizon (DWH) event (April-July 2010, 1500 m water depth). Short-lived radioisotope geochronologies (²¹⁰Pb, ²³⁴Th), organic geochemical assessments, and redox metal concentrations were determined to relate changes in sediment accumulation rate, contamination, and redox conditions with benthic foraminiferal density. Cores collected in December 2010 indicated a decline in density (80-93%). This decline was characterized by a decrease in benthic foraminiferal density and benthic foraminiferal accumulation rate (BFAR) …