Boundaries

This ecoregion includes all coastal drainage basins north of the Rio São Francisco along the northeastern coast of Brazil from the Rio Coruripe basin in Alagoas in the south and Rio Timonha in Ceará, east of the Rio Parnaiba basin. It is limited to the east and north by the Atlantic Ocean, to the south by the drainage divide with the São Francisco basin, and to the west by the drainage divide of the Rio Parnaiba drainage.

Topography

The ecoregion drains the Brazilian Highlands’ northeastern slopes to the sandy coastal plain. Elevations range from sea level to over 1100 m asl in the Serra da Borborema. The escarpments and terraces reveal the eroded sedimentary and crystalline formations of the Brazilian Shield. Some of the ranges include the Serra de Ibiapaba and Serra Grande along the western border, and the Chapada do Araripe in the south.

Freshwater habitats

The ecoregion includes an abundance of coastal rivers and streams, most of which are intermittent in all or part of their course.

Terrestrial habitats

Caatinga is the dominant vegetation type throughout most of the ecoregion, with plants including butterfly sage (Cordia globosa), mandacaru (Cereus jamacaru), xique-xique (Pilosocereus gounellei), and carnauba palm (Copernicia prunifera). In addition to caatinga are pockets of caatinga enclaves moist forest (or brejos) that lie in patches on the Chapada do Araripe, Serra de Ibiapaba, Serra de Baturité, and Serra da Borborema. These moist forests comprise species such as Peltophorum dubium, Cedrella fissilis, and Aspidosperma pyricollum. Coastal vegetation types include restingas, mangroves, and Atlantic moist and semi-deciduous forests.

Description of endemic fishes

There are no endemic genera in the ecoregion. However, 39 known species are strictly endemic to this ecoregion, including more than 87% of Loricariidae in four genera (Ancistrus, Hypostomus, Parotocinclus, Pseudancistrus). The remaining two Loricariidae, Loricariichthys derbyi and Parotocinclus jumbo, are near-endemic in this and one other ecoregion –the Parnaiba [325] and Sao Francisco [327], respectively.

Other noteworthy fishes

The ecoregion is home to Carvalho\'s Surinam toad (Pipa carvalhoi), which resides in wetlands, marshes, ponds and lakes, as well as wet and dry savannas. A population of West Indian manatee (Trichechus manatus) is found around the Rio Piranhas.

Justification for delineation

This ecoregion lies within the East Brazilian ichthyographic region outlined by Gery (1969) and northeast Brazilian ichthyographic province outlined by Ringuelet (1975).

Level of taxonomic exploration

Good