Taxonomy of cryptic species of <italic>Skosgbergia</italic> Ostracod (Myodocopida: Cypridinidae) in Panama

Within the Caribbean, two species of marine ostracod in the genus <italic>Skogsbergia</italic> have been formally described (<italic>Skogsbergia lerneri</italic> and <italic>S. crenulata</italic>). Recent molecular analyses of <italic>Skogsberia</italic> populations from throughout the Caribbean suggest that there are at least six undescribed cryptic species as indicated by highly divergent clades in phylogenies of mitochondrial and nuclear DNA. Identification of cryptic species is key to understanding the mechanisms of speciation in the marine environment. The emergence of the Isthmus of Panama, 3-5 mya, created a barrier to gene flow and isolated marine populations in the Pacific and the Atlantic. This closure caused extreme changes in oceanographic patterns and climate throughout the Caribbean and created opportunities for speciation. A genetically divergent <italic>Skogsbergia</italic> lineage that is endemic to Panama was characterized with light, confocal and scanning electron microscopy to identify diagnostic morphological characters for the potentially new species. The new putative species was compared to the two formally recognized <italic>Skogsbergia</italic> species. Morphological results indicate that several morphological characters were distinct between the Panama specimens and <italic>S. lerneri</italic> and <italic>S. crenulata</italic>. The molecular results suggest that the morphological variation found in the two collection lots of specimens from two different island and habitats might be a result of geographic variation and not indicative of two distinct species. The molecular and morphological data strongly suggest that there is at least one undescribed species of <italic>Skogsbergia</italic> in Panama