Date: 1st June 2010 (Tuesday)
Venue: Conference Rm 2
Host: Dr Ng Ngan Kee
Speaker: Dr Chu Ka Hou (The Chinese University of Hong Kong)
Previous studies on two common widespread intertidal acorn barnacles, Tetraclita squamosa and Chthamalus malayensis, in the Indo-West Pacific region have identified genetically distinct lineages, representing several cryptic species. In this seminar, I summarize the data on COI divergence of the two species complexes to elucidate the geographic distribution and population genetic structure of each lineage, and compare the phylogeographic patterns and timing of speciation events of the species complexes. While the genetic differentiation of both complexes is affected by sea level fluctuations associated with glaciations, T. squamosa, having more stringent habitat requirements (mostly on exposed rocky shores) than C. malayensis (found on shores of varying wave exposures), exhibits a deeper divergence and stronger genetic population structuring. Within each complex, lineages with a continental distribution appear to suffer more in terms of effective population size from sea level changes than those inhabiting islands. Comparative phylogeographic studies on these barnacles suggest that habitat specificity, rather than larval dispersal capability, appears more important in determining population structure and phylogeographic patterns and highlights the importance of islands in serving as refugia for species during glaciation periods.
About the speaker
Dr Chu is a currently a professor at the Department of Biology, Chinese University of Hong Kong. His research interests broadly lies in (1) Molecular Marine Biology and Biotechnology and (2) Biology of crustaceans. Besides his academic position, Prof Chu is holder of numerous other positions. For instance, he is the director of Simon FS Li Marine Science Laboratory. In addition to that, he is also the associate editor and member of editorial board of the journals Sequencing and Marine Biotechnology respectively.
An attentive audience at Dr Chu’s seminar.
[Photograph by Ng Ngan Kee]