Primary Biological Parameters for Conservation of Tropical Eels in the South Pacific Ocean

Freshwater eel populations worldwide are under threat of serious declines, so understanding their biological parameters is essential. Evaluations of the population structures of tropical anguillids (Anguilla marmorata, A. megastoma, A. obscura, and A. reinhardtii) in the western South Pacific Ocean using total number of vertebrae indicate there are likely different types of population structures among the species that are distributed across a wide area from eastern Australia to French Polynesia and north to Micronesia. Anguilla marmorata is the most widely distributed species and likely has several spawning populations. Anguilla megastoma may have eastern and western populations in the western South Pacific, with A. obscura and A. reinhardtii apparently having less regional divergences. Research on the silver eel migrations and early life history characteristics of leptocephali and glass eels of each species or population will help to understand their reproductive ecology and recruitment mechanisms. Information about the specific biological characteristics of the anguillid eel populations in each area of the region are important to provide a scientific basis to guide conservation and management efforts for these species that are mostly only distributed on islands and this information will also increase understanding of the speciation and evolution of anguillid eels.