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Gray Dolphin

Sotalia fluviatilis (Gervais & Deville, 1853)

Source-backed taxonomic record

Accepted species in Catalogue of Life’s 11 September 2026 base release. This preserves the source classification and available supporting data; it is not a completed species monograph.

Open encyclopedia reference

The tucuxi (Sotalia fluviatilis), alternatively known in Peru bufeo gris or bufeo negro, is a species of freshwater dolphin found in the rivers of the Amazon basin. The word tucuxi is derived from the Tupi language word tuchuchi-ana, and has now been adopted as the species' common name. Despite being found in geographic locations similar to those of 'true' river dolphins such as the boto, the tucuxi is not closely related to them genetically. Instead, it is classed in the oceanic dolphin family, Delphinidae.

Physically, the species resembles the bottlenose dolphins, but differs sufficiently to be placed in a separate genus, Sotalia. The Guiana dolphin (Sotalia guianensis), a related dolphin present in coastal and estuarine environments and formerly grouped together with the tucuxi, have recently been recognized as a distinct species.

Wikipedia contributors, Tucuxi; see linked history · CC BY-SA 4.0 . Plain-text lead excerpt, at most 180 words; no infobox or later sections Retrieved 2026-10-05T02:19:50.597345+00:00. This reference remains separate from the taxonomic record.

Identity & source status

Scientific name
Sotalia fluviatilis (Gervais & Deville, 1853)
Name authority
(Gervais & Deville, 1853)
Common name
Gray Dolphin
Rank
species
Accepted status
accepted
Kingdom
Animalia
Phylum
Chordata
Class
Mammalia
Order
Cetacea
Family
Delphinidae
Genus
Sotalia
Extinction status
Recorded extant

Classification family tree

Nested taxonomic groups from the source. This is not a direct-ancestor chain, a dated evolutionary tree or a phylogenetic reconstruction.

  1. domainEukaryota (Chatton, 1925) Whittaker & Margulis, 1978
  2. kingdomAnimalia
  3. phylumChordata
  4. subphylumVertebrata
  5. infraphylumGnathostomata
  6. parvphylumOsteichthyes
  7. megaclassTetrapoda
  8. classMammalia Linnaeus, 1758
  9. subclassTheria Parker & Haswell, 1897
  10. infraclassEutheria Gill, 1872
  11. orderCetacea Brisson, 1762
  12. suborderOdontoceti Flower, 1867
  13. familyDelphinidae Gray, 1821
  14. genusSotalia Gray, 1866
  15. speciesSotalia fluviatilis (Gervais & Deville, 1853)

Close classified relatives

No other member of this genus is present in the selected snapshot.

Browse 32 records assigned to Delphinidae.

Names & synonyms

Names explicitly linked to this accepted taxon in the source. Synonymy can change with revision.

Recorded nameSource status
Delphinus fluviatilis Gervais & Deville, 1853 Gervais & Deville, 1853synonym
Sotalia fluviatilis fluviatilis (Gervais & Deville, 1853) (Gervais & Deville, 1853)synonym
Sotalia pallida (Gervais, 1855) (Gervais, 1855)synonym
Sotalia tucuxi (Gray, 1856) (Gray, 1856)synonym

Documented distribution

Source distribution statements, not a complete range map. A listed locality is not necessarily a place of origin.

South America

Source literature & publication evidence

References attached to this source record, including nomenclatural citations where supplied. This is a selected bibliography; abbreviated citations remain in the source’s form.

  1. https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=180422 Source fields: Taxon.tsv dwc:namePublishedIn, Taxon.tsv dcterms:references

Origins, evidence & remaining research

Name authority and publication references document nomenclature where the source supplies it. They do not establish evolutionary origins or the earliest fossil occurrence.

Specimen-level evidence, morphology, ecological research, phylogenetic studies, a comprehensive bibliography and a located literary passage have not yet been compiled for this record. A suitable sourced image remains to be added.

Dataset citation & attribution

This exact taxon in ChecklistBank · Catalogue of Life 2026-09-11

Catalogue of Life 2026-09-11; dataset 316321; doi:10.48580/dgz5n. https://creativecommons.org/licenses/by/4.0/ . Retrieved 5 October 2026.

Stable key: col:6Z842. Classification follows source parent identifiers. English common names may vary by region.