Population genomics of eels
The search for the spawning areas of catadromous eels (Genus Anguilla) has a history that began with  Aristotle's hypothesis that eels develop spontaneously from mud and so far has culminated with the  discoveries of the European (1922) and Japanese eel (1991) spawning areas. Eels live up to several  decades in freshwater before they travel across the ocean on a journey that sometimes takes months  and ends at their spawning areas. Habitat destruction, overfishing, pollution and introduced parasites  have driven several species to be classified as endangered. In eastern Africa and the islands of the  southwestern Indian Ocean (SWIO) eels are mythical creatures supporting subsistence fisheries. These areas have recently entered the global eel trade heedless of the contribution of these migratory fishes  to the livelihoods of vulnerable human societies. Worldwide, the eels of the SWIO are the least studied stocks and little is known about the marine phase of their life cycle. We propose to tag the endemic  species Anguilla mossambica with satellite transmitters to study their marine migration routes from  Madagascar and possibly locate their spawning area, which they may share with one or more of the  co-occurring species (A. marmorata, A. bicolor bicolor, A. bengalensis labiata). We will explore the  oceanographic conditions along the eels' migration path in order to potentially identify landmarks that  the eels could use to find their spawning area. We will use next generation sequencing techniques to  reveal population structure and screen for hybrids and backcrosses among all four species of eels  throughout their SWIO distribution range. We will connect our research with an ongoing project  studying eel recruitment to and escapement from estuaries in South Africa, Mozambique and Kenya  granted from the Western Indian Ocean Marine Science Association (2020-2023) to two of the  applicants. We have brought together an international team of biologists and oceanographers from  Europe, Africa, and Japan. Learning about the locations of the spawning areas of these species and  gathering new information about their population structures and potential levels of hybridization will  be valuable new information that can help guide future conservation efforts.