Manta and devil rays are filter-feeding elasmobranchs that are found circumglobally in tropical and subtropical waters. Although relatively understudied for most of the Twentieth century, public awareness and scientific research on these species has increased dramatically in recent years. Much of this attention has been in response to targeted fisheries, international trade in mobulid products, and a growing concern over the fate of exploited populations. Despite progress in mobulid research, major knowledge gaps still exist, hindering the development of effective management and conservation strategies. We assembled 30 leaders and emerging experts in the fields of mobulid biology, ecology, and conservation to identify pressing knowledge gaps that must be filled to facilitate improved science-based management of these vulnerable species. We highlight focal research topics in the subject areas of taxonomy and diversity, life history, reproduction and nursery areas, population trends, bycatch and fisheries, spatial dynamics and Stewart et al. Research Priorities for Mobulid Rays movements, foraging and diving, pollution and contaminants, and sub-lethal impacts. Mobulid rays remain a poorly studied group, and therefore our list of important knowledge gaps is extensive. However, we hope that this identification of high priority knowledge gaps will stimulate and focus future mobulid research.

NK T (NKT) cells play important roles in the regulation of diverse immune responses. However, little is known about the mechanisms that regulate homeostasis and activation of these cells. Thymic NKT cells up-regulated the chemokine receptor CXCR6 following positive selection and migrated toward CXCL16 in vitro. However, CXCR6 was not essential for thymic development or maturation. In contrast, liver and lung NKT cells were depleted in CXCR6+/− and CXCR6−/− mice. The reduction in liver and lung NKT cells coincided with an increase in bone marrow NKT cells, suggesting a redistribution of NKT cells in CXCR6−/− animals. In wild-type mice, CXCL16 neutralization reduced accumulation of mature NK1.1+, but not immature NK1.1− NKT cell recent thymic emigrants in the liver. Given that thymic NKT cells are preferentially exported as NK1.1− cells, this suggests an additional role for CXCR6/CXCL16 in maturation or survival of immature liver NKT cells. CXCL16 blockade did not deplete resident NK1.1+ NKT cells, indicating that CXCR6/CXCL16 are not required to retain mature NKT cells in the liver. Cytokine production by liver and spleen NKT cells was impaired in CXCR6−/− mice following in vivo stimulation with α-galactosylceramide, implicating a novel role for CXCR6 in NKT cell activation. Reduced IFN-γ production was not due to an intrinsic defect as production was normal following PMA and ionomycin stimulation. Preformed transcripts for IL-4, but not IFN-γ, were reduced in CXCR6−/− liver NKT cells. These data identify critical roles for CXCR6/CXCL16 in NKT cell activation and the regulation of NKT cell homeostasis.

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Indonesian Manta Ray Habitat Use disturbance to this threatened species by tourism, regulations for the number of boats and interactions, especially during key reproductive times should be considered. Further, strict fishing regulation in the area is recommended as fishing gear entanglement was identified as a threat to this population.