Gray Dolphin
Sotalia fluviatilis (Gervais & Deville, 1853)
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.
- domainEukaryota (Chatton, 1925) Whittaker & Margulis, 1978
- kingdomAnimalia
- phylumChordata
- subphylumVertebrata
- infraphylumGnathostomata
- parvphylumOsteichthyes
- megaclassTetrapoda
- classMammalia Linnaeus, 1758
- subclassTheria Parker & Haswell, 1897
- infraclassEutheria Gill, 1872
- orderCetacea Brisson, 1762
- suborderOdontoceti Flower, 1867
- familyDelphinidae Gray, 1821
- genusSotalia Gray, 1866
- speciesSotalia fluviatilis (Gervais & Deville, 1853)
Close classified relatives
No other member of this genus is present in the selected snapshot.
Names & synonyms
Names explicitly linked to this accepted taxon in the source. Synonymy can change with revision.
| Recorded name | Source status |
|---|---|
| Delphinus fluviatilis Gervais & Deville, 1853 Gervais & Deville, 1853 | synonym |
| 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.
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.
- 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.