Guiana dolphin

Sotalia guianensis
Other names: 
  • Costero
  • Freshwater tucuxi
  • Sotalia
Maximum length: 
  • Male: 1.95m
  • Female: 1.95m
  • Calf: 0.7m
Maximum weight: 
  • Male: Unknown
  • Female: 60 kg
  • Calf: Unknown
Diet: 
  • Fish
  • Squid
  • Crabs
Estimated population: 
Unknown
IUCN Listing: 
DD
CITES Appendix: 
I
CMS Appendix: 
II
Classification: 

The controversy surrounding the taxonomy of the Sotalia genus has finally been laid to rest. The two 'populations' have recently been formally recognised as separate species; S. fluviatalis, otherwise known as the tucuxi, is a freshwater species, whilst S. guianensis is marine, and now known as the Guiana dolphin. For conservation and management purposes, preliminarily suggestions have been made to recognise eight populations of the Guiana dolphin throughout its range. Further research is needed in order to establish the distribution limits of both Sotalia species in the mouth of the Amazon River and the Amazonian Estuary as well as in the Orinoco River.

 

Appearance: 

Individuals in the genus Sotalia are similar in overall appearance to the bottlenose dolphin although they are smaller, have a low triangular dorsal fin, broad flippers, and a narrow more pronounced beak. Colouration ranges from blue to grey with a lighter underside of white, grey, or pink. The Guiana dolphin is generally larger than the tucuxi with individuals up to 30% larger, although where their range overlaps it would be virtually impossible to distinguish between the two species.

 

Behaviour: 

Sotalia are usually found in small groups of only a few individuals although they can also be seen in groups of 20 or even 30 in coastal areas. They are extremely sociable and perform impressive acrobatics, including spyhopping, lobtailing, flipper slapping, and porpoising. They are not known to bow-ride, and although relatively shy and difficult to approach, they can be inquisitive. They make short dives, usually lasting 30 seconds to one minute, and photo-identification studies in southern Brazil have shown some individuals to display long-term residency in one area. Misidentification with bottlenose dolphins is common however the smaller size, smaller beak and paler colour of the Guiana dolphin are enough to avoid confusion between the species.

 

Distribution: 

The Guiana dolphin is found in nearshore and coastal waters along the Atlantic coast of South and Central America, from southern Brazil in the south to Nicaragua in the north. They are also found around some of the Caribbean islands. Threats to this species include direct kills – because of perceived competition and traditional medicine use, although interestingly they are also protected in many parts of their range because of myth and legend - pollution, accidental bycatch and entanglement in fishing gear, human disturbance and habitat degradation. Comprehensive population estimates are not available and the IUCN lists this species as Data Deficient (2008).

 

Distribution map: