The Cetaceans of Mauritania, West Africa: a concise zoogeographical review with two new species records

The exact number of cetacean species present in Mauritanian waters is unknown. A first overview was published only in 1980, the latest in 1998. Yet, published information remains modest compared to, e.g., neighboring Senegal (first review in 1947). The complex oceanography of Mauritanian waters permits a mixed assemblage of cetacean fauna, with the distribution of both cool temperate and (sub) tropical species. In this review, we use our own observations from strandings, bycatches and vessel-based surveys, as well as published and grey literature, to support an updated inventory of cetaceans of Mauritania. This checklist includes two new authenticated species records: Kogia sima (Owen) (Kogiidae) and Lagenodelphis hosei Fraser (Delphinidae). Stenella coeruleoalba (Meyen) (Delphinidae) is verifiably documented for the first time. Further, a first specimen record of Stenella longirostris (Gray) (Delphinidae) is described, as well as second specimen records of Mesoplodon europaeus (Gervais) (Ziphiidae), Steno bredanensis (G. Cuvier) (Delphinidae) and Megaptera novaeangliae (Borowski) (Balaenopteridae). Of 30 reported species, 27 (of six families) are fully supported, while three species lack (accessible) voucher material though probably (P) occur in Mauritania: Balaenopteridae: Megaptera novaeangliae (Borowski), Balaenoptera musculus (Linnaeus), B. borealis Lesson, B. omurai Wada, Oishi and Yamada, B. acutorostrata Lacépède, B. physalus (Linnaeus) and B. brydei Olsen (P); Physeteridae: Physeter macrocephalus Linnaeus; Kogiidae: Kogia sima (Owen) and K. breviceps (Blainville); Delphinidae: Sousa teuszii (Kükenthal), Tursiops truncatus (Montague), Delphinus delphis Linnaeus, Stenella frontalis (G. Cuvier), Stenella attenuata (Gray), Stenella coeruleoalba (Meyen), Stenella longirostris (Gray), Stenella clymene (Gray), Steno bredanensis (G. Cuvier), Peponocephala electra (Gray) (P), Lagenodelphis hosei (Fraser), Grampus griseus (G. Cuvier), Globicephala macrorhynchus Gray, Globicephala melas (Traill) (P), Orcinus orca (Linnaeus) and Pseudorca crassidens (Owen); Ziphiidae: Ziphius cavirostris G. Cuvier, Mesoplodon europaeus and Mesoplodon densirostris (de Blainville); Phocoenidae: Phocoena phocoena (Linnaeus). Finally, we report the first case for continental northwest Africa of tattoo skin disease in a stranded D. delphis.