A molecular investigation of two similar Asteroids seperated by the Drake Passage


Meeting Abstract

P1.142  Jan. 4  A molecular investigation of two similar Asteroids seperated by the Drake Passage JANOSIK, Alexis M.*; HALANYCH, Kenneth M.; Auburn University, Auburn, AL; Auburn University Auburn, AL janosam@auburn.edu

Antarctica separated from the southern tip of the South American continent approximately 41 millions years ago and has been isolated since. This separation led to the establishment of the Antarctic Circumpolar Current (ACC), which is considered to be one the primary forces driving speciation in the Southern Ocean. In spite of drastic isolation, many marine taxa show little to no endemism and it has been suggested that 18% of Asteroidea, Ophiuroidea, and Echinoidea are found in both South America and Antarctica. Odontaster validus and Odontaster penicilatus are morphologically similar species found in different geographic regions, with O. penicilatus restricted to South American waters and O. validus found as a circumpolar Antarctic species. The relationships or potential for genetic exchange between Odontaster in these two regions has never rigorously been examined. Furthermore, Odontaster has pelagic larvae, making gene flow across the ACC potentially feasible. Using sequence data from COI and 16S mitochondrial genes, we are examining the degree of genetic similarity in these two morphologically similar species and if recent gene flow has occurred between the Antarctic Peninsula and South American waters.

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