Boundaries

This ecoregion includes the most of the Philippine islands from the Batan Islands and Luzon in the north to Negros, Bohol and Siargao of the Visayas in the south. It excludes the western islands of Mindoro and Palawan, which are in the Palawan-Busuanga-Mondoro ecoregion [756].

Freshwater habitats

The northern part of Luzon contains the larger river basins of the Cagayan, Agno and Pampanga, as well as developed floodplains. Southern Luzon contains most of the larger lakes. Most of the smaller islands lack natural lakes (Davies et. al. 1990).

Terrestrial habitats

Terrestrial ecoregions include the Luzon rain forests, Luzon montane rain forests, Luzon tropical pine forests, Mindanao-Eastern Visayas rain forests, and Greater Negros-Panay rain forests (Wikramanayake et al. 2002).

Description of endemic fishes

It is estimated there are about 40 endemic species that require freshwater at some stage of their life cycle. There are also several endemic genera, including Caecogobius, Gulaphallus, and Mistichthys.

Other noteworthy fishes

Caecogobius cryptophthalmus is the only known cave-dwelling species in the Philippines.

Justification for delineation

For Southeast Asia, delineations were determined using a bottom-up approach that employed both published and unpublished field data and expert assessment (Abell et al. 2008; Herre 1953). This ecoregion’s fauna consists mainly of either marine species entering inland waters or freshwater species derived from marine ancestors (M. Kottelat pers. comm. 2006).

Level of taxonomic exploration

Although there is quite a number of publications on the taxonomy of Philippine fishes, the data set for freshwater fish communities is still very poor. There are few faunistic studies of a single basin or single island. Therefore, numerous new records have to be expected, as well as a number of island endemics. Studies on Leyte Island, for example, have shown that some species may be restricted on a single or few very short coastal creeks (M. Kottelat pers. comm. 2006).