The Atlantic humpback dolphin (Sousa teuszii) is a relatively small (c. 2.5 m) species endemic to the west coast of Africa in the eastern Atlantic Ocean.  The species is characterised by a robust body, a diagnostic long, thick hump on the dorsal surface on which the small dorsal fin is situated, and a long and slender beak.

The distribution and status of Atlantic humpback dolphins is very poorly known.  It is currently confirmed to occur in the coastal waters of nine range states comprising Morocco, Mauritania, Senegal, The Gambia, Guinea-Bissau, Guinea-Conakry, Cameroon, Gabon and Angola.  Evidence suggests that dolphin distribution is discontinuous within this range, with sightings absent from some studied areas e.g. Ghana and Benin (Van Waerebeek et al., 2004). 

There are no data available regarding population size in any of the known range states, though estimates from the best-studied areas vary from as few as 28 animals in Dahkla Bay (Senegal) to perhaps several hundred animals in Canal do Gêba-Bijagos (Guinea-Bissau) (Van Waerebeek et al., 2004).  Since this endemic species is both restricted in geographic distribution and appears to be uncommon throughout most of its existing range, the total worldwide population is likely to be low.  However, limited evidence suggests that by-catch in fishing nets and deliberate hunting for meat are significant causes of mortality, and may have caused local extinction in some areas (Van Waerebeek et al., 2004). 

The International Union for Conservation of Nature and Natural Resources (IUCN) currently classifies Atlantic humpback dolphins as Data Deficient (though this classification is likely to change to threatened), and they are included on the Convention on Migratory Species (CMS)’s Appendix II (unfavourable conservation status), and the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES) Appendix I (threatened).

Due to the general absence of research in the West African region little is known of the behaviour, biology and ecology of Atlantic humpback dolphins, although they are generally assumed to have similar habits to the closely-related and comparatively well-studied Indo-Pacific humpback dolphin (S. chinensis) which occurs in the Indian Ocean, south-east Asia and northern Australia.  This species inhabits tropical and subtropical waters close to shore (usually <25 m water depth), particularly within bays and estuaries and in association with rocky reefs.  On open coasts such as found along most of Angola’s coastline, humpback dolphins are usually observed just seaward of the surf line.  Limited stomach content data indicate that Atlantic humpback dolphins have a piscivorous diet, taking fish such as mullet.  Humpback dolphins have been recorded in groups of up to 37 animals in the Saloum Delta in Senegal, but groups of 4 to 7 seem more typical in other West African regions.