Christine Dudgeon (right), Jenny Ovenden (centre) are pleased to host a visit by Dr Gregory Maes (KU Leuven - JCU). Greg gave an interesting seminar yesterday "Application of genomic tools to inform conservation and management of the Galapagos shark (Carcharhinus galapagensis)", which stimulated lots of discussion about genomics and genetics of elasmobranch species from Australia and worldwide. Greg Maes did his postgraduate training at the University of Leuven (Belgium) on population and conservation genetics of aquatic organisms, focusing on exploited and endangered species such as eels, flatfishes, pikes, hybridogenetic frogs and polyploid invasive carps. He spent 6 years doing various postdocs in Belgium, Finland and Canada, examining the applications of population⁄conservation genomics approaches to exploited freshwater and marine fishes at various spatio-temporal scales. His main interest lies in multidisciplinary connectivity assessments, molecular traceability and the genomic basis of fisheries induced evolution in exploited species. He is currently an Adjunct senior lecturer in Evolutionary and Applied Genomics at James Cook University.
The recent article on switch from sexual to asexual reproduction in zebra sharks has achieved a high altimetric attention score. It was in the top 5% of all research outputs ever tracked by Altimetrics. Christine Dudgeon's achievement shows that workers who divide their time between science and family duties can make important contributions to both. Photo: Chris and zebra shark in waters of Southeast Queensland.
Published today, Christine Dudgeon's new paper shows that a female Stegastoma fasciatum (leopard, zebra shark) alternated between sexual and asexual reproduction in the Townsville aquarium. In the absence of her mate, genotyping confirmed a batch of pups were not the result of sperm storage and sexual reproduction as expected. Three juvenile sharks were homozygous for maternal alleles found only in the shark mother confirming asexual reproduction. The results coincide with release of the IUCN Red List of Threatened Species which identifies the S. fasciatum as endangered.
MFL associate, Christine Dudgeon, attended the inaugural Citizen Science conference in Canberra on 23-24 July 2015. Citizen science is the collaboration between members of the public and scientists to design research projects and collect and analyse the data. At present, Chris is working with Jenny and colleagues at MFL on the genetic stock structure of three inshore fish species in northern Australia. Find out more here.
At the MFL, we are keen to develop genetic methods for assessing abundance of fisheries populations. One method being explored is genetic effective population size. We are focusing on shark and ray populations, because they are generally less abundant than species like finfish and shellfish and the math is easier. A new study that was published today trials this method on leopard sharks. Christine Dudgeon and Jenny Ovenden found that genetic and conventional estimates of the numbers of adults in an aggregation off the coast of south-east Queensland were similar. This is one of very few studies worldwide that have been able to make this type of comparison. Its important it demonstrates how abundance can be inferred from DNA. Assuming tissue samples are available, the DNA method is quick and easy compared to tagging sharks and observing their occurrence over the years as a way of estimating abundance. Species can be more adequately protected when estimates of abundance are available. Email Christine Dudgeon (c.dudgeon at uq.edu.au, where at = @) for a copy of the paper. To find out more about Christine's leopard shark project in Thailand, click here.