Sousa teuszii (Kükenthal, 1892)
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publication ID |
https://doi.org/ 10.5281/zenodo.6610922 |
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https://doi.org/10.5281/zenodo.6611052 |
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persistent identifier |
https://treatment.plazi.org/id/BD4CCC61-763D-FFF5-FF69-FEF3EEFAF973 |
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Diego |
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Sousa teuszii |
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16. View On
Adantic Humpback Dolphin
French: Dauphin de Teusz / German: \Westafrika-Buckeldelfin / Spanish: Delfin jorobado atlantico
Other common names: Atlantic Humpbacked Dolphin, Teusz's Dolphin
Taxonomy. Sotalia teusziz Kukenthal, 1892 ,
“aus Kamerun,” (= Cameroon), Cameroun Oriental, Bay of Warships, near Douala.
There have been questions over the years as to whether or not S. feuszii is a distinct species. Nevertheless, genetic studies and morphological studies of skulls collected worldwide have determined that S. tewszi is a distinct species of Sousa . Monotypic.
Distribution. Near-shore waters of tropical and subtropical West Africa, from the Western Sahara to S Angola. View Figure
Descriptive notes. Total length 260 cm (males) and 235 cm (females); weight up to 284 kg (males). Neonates are ¢.100 cm in length. Like the Indo-Pacific Humpback Dolphin ( S. chinensis ), the Atlantic Humpback Dolphin has medium-sized robust body. It has long, distinct beak and moderately deepened tailstock. Dorsal fin of the Atlantic Humpback Dolphin varies in shape. It arises from wide, pronounced hump on middorsal side, and fin is generally small and falcate. The Atlantic Humpback Dolphin has broad flippers with rounded tips. Skin pigmentation is typically gray on back and sides and whitish underneath. Some individuals have dark specks on tailstock and below anterior edge of dorsal fin. There appears to be some sexual dimorphism in size, with males reaching greater lengths than females. Tooth count of the Atlantic Humpback Dolphin tends to be lower than that of the Indo-Pacific Humpback Dolphin; upperjaw contains 27-32 teeth and lowerjaw contains 26-31 teeth.
Habitat. Tropical, coastal, and estuarine habitat, predominantly shallow, near-shore waters with soft sediment bottoms. Atlantic Humpback Dolphins will occupy riverine habitats but generally stay within the range oftidal influence. They can tolerate waters with highly variable salinities.
Food and Feeding. Little is known about the diet of the Atlantic Humpback Dolphin. They generally feed in near-shore waters and around rocky reefs. Off the coast of Flamingos, Angola, cooperative herding of prey has been observed, with individuals using the coast to trap prey. Prey species primarily consist of small schooling fish including mullet ( Mugil spp. ), grunts (Pristipoma jubelini), bonga fish ( Ethmalosa fimbriata), South African mullet ( Liza richardsonii), Atlantic bonito ( Sarda sarda), and sardines ( Sardinella spp. ).
Breeding. As with feeding ecology,little is known about the life history of the Atlantic Humpback Dolphin. Mating activity has been observed in March-April, but breeding may occur over a longer time period. Length at sexually mature of a male is ¢.200 cm.
Activity patterns. Typical daytime behaviors of Atlantic Humpback Dolphins include traveling, foraging, and socializing. There is no evidence for any obvious diurnal trends. Nevertheless, in the Flamingos region of Angola, Atlantic Humpback Dolphins spend more time foraging during flood tide and more time traveling during ebb and low tides. These individuals are generally observed swimming slowly and regularly surfacing; their average swim speed was 3-9 km/h. Off Flamingos, individuals foraged in one area for several hours, with dive times of more than one minute in length. Aerial behavior is uncommon.
Movements, Home range and Social organization. The Atlantic Humpback Dolphin generally travels in groups of 5-7 individuals, although groups of up to 30-40 individuals have been reported. It has been observed in mixed-species groups with the Common Bottlenose Dolphin ( Tursiops truncatus ). Whistles of Atlantic Humpback Dolphins off Angola were 2-5-23-4 kHz and mostly simple, with one inflection point. The Atlantic Humpback Dolphin does not seem to display any seasonally dependent movements, and there is no indication of any long-distance migrations.
Status and Conservation. CITES Appendix I. Classified as Vulnerable on The IUCN Red List. Abundance of Atlantic Humpback Dolphin is estimated to be fewer than 10,000 individuals, with each subpopulation estimated at less than 1000 individuals. The total population is suspected to be in decline. Threats of most concern are direct and incidental catch. Incidental bycatch has been reported from Morocco (Western Sahara), Senegal, and Guinea-Bissau. Heavy use of inshore gillnets and beach seines is a major threat to the Atlantic Humpback Dolphin. West Africans have been known to hunt Atlantic Humpback Dolphins, mainly with harpoons, for human consumption. Local fishing communities of Joal and Fadiouth in Senegal and some other communities along the Petite Cote engaged in traditional hunts until at least 1996. Other threats include environmental contamination, habitat destruction (specifically from harbor construction and expansion and offshore industries), overfishing of prey species,live captures for aquaria, and vessel collisions.
Bibliography. Jefferson et al. (2008), Parra & Ross (2009), Reeves, Collins et al. (2008), Ross (2002), Ross et al. (1994), Van Waerebeek et al. (2004), Weir (2009, 2010), Weir et al. (2010).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
