Genetics of manta and devil rays: Evolution, population genetics and conservation of a group of vulnerable pelagic filter-feeders

Mobulids are large pelagic filter-feeders and amongst the most vulnerable of all chondrichthyan species due to slow life histories and extremely low fecundity. Unfortunately, large and expanding fisheries exist in various Asian countries driven by the use of mobulid filter plates in Chinese medicine. Mobulids are also frequently caught as bycatch in tuna purse seine fisheries across their entire range. Due to the low intrinsic growth rate of mobulid populations, even low catch rates can result in significant population declines.
The evolutionary history of mobulid rays has remained enigmatic despite considerable recent interest in mobulid ecology and conservation. This thesis was designed to provide baseline information on mobulid evolution and population genetics, in order to inform mobulid management and better target conservation measures. I used Next Generation Sequencing of entire mitochondrial genomes, conventional Sanger sequencing and supplementary GenBank sequences to research: 1) the timing, pattern and drivers of the evolution of all mobulid species; 2) the influence of past climate change on the historical population structure and demography of one of the larger mobulid species, the spinetail devil ray; and 3) conservation concerns and solutions for this vulnerable group of pelagic elasmobranchs.