ABSTRACT
In the Indo-Pacific areas, the Caribbean region, West Africa, Central America and North of South America, river systems are colonised by freshwater gobies with a life cycle adapted to the conditions in these distinctive habitats which are, particularly in islands, young oligotrophic rivers subject to extreme climatic and hydrological seasonal variation. Th ese species spawn in freshwaters, the free embryos drift downstream to the sea where they undergo a planktonic phase, before returning to rivers to grow and reproduce (McDowall, 1997; Keith, 2003), hence they are called amphidromous (Fig. 2.5.1.) (McDowall, 1988, 1997, 2004). Th e practical details of their biological cycle and the parameters leading to such evolution in amphidromous gobies are poorly known, but our knowledge increases each year. Th ese gobies contribute most to the diversity of fi sh communities in the Indo-Pacifi c and the Caribbean insular systems, and have the highest
levels of endemism (Keith, 2002a; Lim et al., 2002; Marquet et al., 2003; Keith, 2003; Lord and Keith, 2006; Lord and Keith, 2007). At certain times of the year, the biomass of larvae migrating upstream is so great that they represent an important source of food for local human populations in certain archipelagos (Manacop, 1953; Delacroix, 1987; Bell, 1999; Keith et al., 2008). However, harvesting of this food resource is highly unsustainable, on account of the complexity of the species’ life cycle.
