HUMPBACK DOLPHIN

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Scientific name: Sousa teuszii (KÜkenthal, 1892)

IUCN Status: Critically endangered as listed by IUNC 2017

Geographical range: Mauritania, Senegal, The Gambia, Guinea-Bissau, Guinea (Conakry), Togo, Benin, Nigeria, Cameroon, Gabon, The Republic of Congo, and report of Angola, Morocco and southwest coast of Africa by Jefferson and Waerebeek, (2004).    

Population: 1500 matured individual (Collins et al., 2017) (Decreasing population)

FACTS

 They are a middle size delphinid Dolphin (Waerebeek et al., 2017), endemic to the subtropical and tropical region Eastern Atlantic nearshore water of West Africa (Waerebeek et al., 2004, Waerebeek et al., 2017), though the animal is found frequently nearshore but not exclusively, they could also be found away from nearshore (Weir and Collins, 2015) They are named after the German professor Willy Kükenthal (Waerebeek et al., 2004), in Morphology, they have a prominent dorsal hump, uniform gray adult coloration, wide skull, and low tooth count (Jefferson and Waerebeek, 2004). The research by Jefferson and Waerebeek, (2004) using the morphology (Skull) brought about the suggestion that the West African specie should be separated from his cousin in Asian (Sousa- Genera) because of the distinct observable difference in skull characteristics

Historical claims of the presence of the specie in Nigeria (KIinowska, 1991, Maigret, 1994) was taught to be vague because there were no records to prove her existence, until 2011 when two Humpback Dolphin (Sousa teuszii) were killed in Brass (Bayelsa state) (Waerebeek et al., 2017). Olakunle and Akanbi (2014) claimed to have sighted 33 individuals of the animal but with no evidence to ascertain the claims (No pictures, No Geographical location, etc.) (Waerebeek et al., 2017). There is a suggestion that several of the animals could have being caught and butchered in the Niger Delta region of Nigeria but were not recorded (Waerebeek et al., 2017). Almost 120 years of claim about the presence of Sousa teuszii in Cameroon before it was finally sighted by (Ayissi et al. 2014, Waerebeek et al., 2017), similarly, the sighting of the species in Senegal happened after 50 years of a previous claim of her presence (Weir, 2015) and four individual was sighted by Zwart and Weir (2014) in Guinea.  

Habitat:  They inhabited shallow water, nearshore and they are strongly influenced by tides with sandbanks (Moores, 2018), The West African species was reportedly found in Morocco and Angola (Jefferson and Waerebeek, 2004), but it is uncertain if they are migratory specie, the Asian Humpback was reported to move geographically from one place to another (Waerebeek et al. 2004) and overlap a closer sister specie found within the Asian pacific (Jefferson and Waerebeek, 2004).

Collins et al. (2017) stated March and April (Maigret, 1980) as the period the animal give birth, and they may exhibit sexual dimorphism with male reportedly larger at maturity with a more prominent dorsal Hump.

Feeding: There was a report by Waerebeek et al. (2004) that the animal feed on fish and mullet (Collins et al., 2017)

ANONYMOUS INFORMATION  

They have a distinctive hump at their back that differs from the common bottlenose Dolphin, and they are said to be a shy animal that prefers to stay away from human sight (Uk whales), science daily refers to them as the most endangered mammals in Africa, and could attain a length of 2.5 m or more than 8 feet. They could swim along the Ocean floor when in deeper water, and uses this medium to avoid predators like whale and shark (animal diversity).

Reproduction: They are polygynous and they are capable of reproduction between the ages of 4-8 with a single offspring on average in a year but sexual maturity age or range is unknown according to (Animal diversity)

CONSERVATION STATUS

Threat:  In a survey done by (Waerebeek et al., 2004), 66% (50 interviewers) indicated they are shark (Dolphin) hunter, 94% of the fisherman has caught Dolphin at least once. The captured Dolphin was mostly used as a bait to capture shark (Waerebeek et al., 2004, UNEP/CMS/COP12/Concerted Action 12.3), while some sold it out for $312 – $625 depending on size (Waerebeek et al., 2004). Human contact remains the biggest threat to the species. Being a nearshore animal will no doubt contribute to the frequent interaction with humans (Weir, 2015) in the past that will have contributed to his decreasing population and is the IUCN status of being critically endangered (Weir et al., 2010). Other threat includes: Habitat fragmentation, anthropogenic factors like plastic, refuse and sewage, a decline in fish in their habitat, and a high poverty rate of the locals surrounding the animal habitat.

EXTINCTION REALITIES

WHAT IF, THE ANIMAL GO INTO EXTINCTION?

The West Africa Dolphin helps to maintain the population of fish and maintain fish species balance in their habitat, while also playing an important role in being part of a Food chain. 

THE LOST OF THE SPECIES WILL ALTER THE FOOD WEB AND MAY FAVOR THE ABUNDANCE OF SOME FISH SPECIES TO ANOTHER WHICH IN TURN MAY LEADS TO DECREASE IN POPULATION OF THE LESS FAVOR FISH.   

REFERENCE

Waerebeek, K.V., uwagbae, M., Segniagbeto, G., BAMY, I.L. and Ayissi, I. (2017). New records of Atlantic Humpback Dolphin (Souza teuszii) in Guinea, Nigeria, Cameroon and Togo underscore pressure from Fisheries and marine bush meat demand, Revue d’Ecologie (Terre et Vie). 72 (2):192-205 192   

Zwart, S.J. and WEIR, C.R. (2014). Filling in the gaps: first record of Sousa teusziiin Benin (Gulf of Guinea: Africa). Marine Biodiversity. Records.DOI: 10.1017/S1755267214000578.

Kükenthal, W. (1892). Sotalia teusziin n. species. ein pflanzenfressender  (?) Delphin aus Kamerun. Zoology Jahrb. Abt. Syst., 6: 442-446.

Klinowska, M. (1991). Dolphins, porpoises and whales of the world: The IUCN Red Data Book. IUCN, Gland, Switzerland and Cambridge, UK.

Maigret, J. (1994). Marine mammals and fisheries along the West African coast. Rep. Int. Whal. Commn. (Special issue 15): 307-316.

Waerebeek, K.V., Barnett, L., Camara A., Cham, A., Diallo, M., Djiba, A., Jallow, A.O., Ndiaye, E., Bilal, A.O. and Bamy, I.L (2004). Distribution, Status, and Biology of the Atlantic Humpback Dolphin, Sousa teuszii (Kükenthal, 1892), Aquatic Mammals, 30(1): 56-83, DOI 10.1578/AM.30.1.2004.56

Jefferson, T.A. and Waerebeek, K.V. (2004). Geographic Variation in Skull Morphology of Humpback Dolphins (Sousa spp.), Aquatic Mammals. 30(1): 3-17, DOI 10.1578/AM.30.1.2004.3

Ayissi, I., Segniagbeto, G.H. and Waerebeek, K.V. (2014). Rediscovery of Cameroon Dolphin, the Gulf of Guinea Population of Sousa teuszii (Kükenthal, 1892), Hindawi Publishing Corporation. doi.org/10.1155/2014/819827

 The Concerted Action for the Atlantic Humpback Dolphin was first adopted at the 12th Meeting of the Conference of the Parties (UNEP/CMS/COP12/Concerted Action 12.3), United Nation Environmental program.

Moores, R. (2018). The future of Atlantic Humpbacked Dolphins Sousa teuszii in Dakhla Bay, Atlantic Sahara, Go-South Bull. (15): 166-171

Weir, C.R. (2015). Photo-identification and habitat use of Atlantic humpback dolphins Sousa teuszii around the Río Nuñez Estuary in Guinea, West Africa, African Journal of Marine science, DOI: 10.2989/1814232X.2015.1069757

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