Abstract
Scientists have long sought to uncover the secrets of the migration of anguillid eels, genus Anguilla. As catadromous fishes, anguillid eels spend most of their lives in freshwater until they return to their spawning grounds in the tropics, although part of the population never enters freshwater and instead resides in brackish and marine areas close to coastlines. Molecular phylogenetic research suggests that anguillid eels originated from deep-ocean midwater marine anguilliform species and that tropical eels originating from the Indo-Pacific region are the most basal species of anguillid eels. Anguillid eels left the tropical ocean to colonize temperate areas. The yearly spawning of tropical species and constant larval growth throughout the year extend to periods of recruitment in continental habitats to last all year for tropical eels. Tropical eels such as A. celebesensis and A. borneensis have relatively short migrations periods of less than 100 km to their spawning grounds. Conversely, the temperate European eel A. anguilla travels the longest distances and migrates more than 5000 km across the Atlantic Ocean to spawn in the Sargasso Sea. The ancestral state of migration in the genus Anguilla may have been local, short-scale and nonseasonal spawning migration throughout the year as defined in tropical eels. With the expansion of dispersion of global oceanic migration across the world, migration scales can gradually change. Temperate anguillid eels migrate thousands of kilometres from spawning areas to coastal and inland water habitats while retaining spawning areas in tropical areas, accompanied by seasonal downstream and spawning migrations with consequences for seasonal recruitment. Recent advances and the availability of electronic tags such as pop-up satellite archival tag could reconstruct the entire spawning migration from continental growth habitats to spawning sites with detailed migration behaviours and routes. Migration ecology and mechanisms throughout the life of anguillid eels have gradually been revealed in recent decades.
Highlights
Anguillid eels, genus Anguilla Schrank, 1798, represent one of the most unique eel groups of the Anguilliformes, consisting of 20 families, 147 genera and 820 species (Nelson, 2006; Johnson et al, 2011)
This paper examines the ancestral oceanic migration mechanisms observed in anguillid eels and how anguillid eels evolved to endure longdistance migratory paths to return from their temperate growth habitats to their tropical spawning areas
Appropriate molecular phylogenetic studies suggest that the genus Anguilla originated from the tropical Indo-Pacific region and that A. borneensis or A. mossambica may be an ancestor distributed across the Indo-Pacific Ocean (Aoyama et al, 2001; Lin et al, 2001; Minegishi et al, 2005; Teng et al, 2009; Tseng, 2016; Zan et al, 2020)
Summary
Genus Anguilla Schrank, 1798, represent one of the most unique eel groups of the Anguilliformes, consisting of 20 families, 147 genera and 820 species (Nelson, 2006; Johnson et al, 2011). Anguillid eels are the only genus in which all species lead catadromous life patterns of migrating between coastal and inland water growth habitats and offshore spawning areas (McDowall, 1988). G., Tzeng et al, 1997; Tsukamoto et al, 1998; Daverat et al, 2006; Jessop et al, 2008; Arai and Chino, 2012, 2018; Yokouchi et al, 2012; Marohn et al, 2013; Arai et al, 2020) These migratory history studies have found diverse migration patterns between marine and freshwater habitats in anguillid eels. This paper examines the ancestral oceanic migration mechanisms observed in anguillid eels and how anguillid eels evolved to endure longdistance migratory paths to return from their temperate growth habitats to their tropical spawning areas. Recent ecological studies in combination with molecular genetic studies and the availability of electronic tags such as pop-up satellite archival tag are gradually uncovering the mysterious life history of anguillid eels
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
