Hexatrygon bickelli Heemstra & Smith, 1980

Open encyclopedia reference

The sixgill stingray (Hexatrygon bickelli) is a species of stingray and the only extant member of the family Hexatrygonidae. Although several species of sixgill stingrays have been described historically, they may represent variations in a single, widespread species. This flabby, heavy-bodied fish, described only in 1980, is unique among rays in having six pairs of gill slits rather than five. Growing up to 1.7 m (5.6 ft) long, it has a rounded pectoral fin disc and a long, triangular, and flexible snout filled with a gelatinous substance. It is brownish above and white below, and lacks dermal denticles. Benthic in nature, the sixgill stingray is usually found in deep waters over upper continental slopes and seamounts at depths of 500–1,120 m (1,640–3,670 ft), the deepest-living stingray species known. It has been recorded from scattered locations in the Indo-Pacific from South Africa to Hawaii. This species probably uses its snout to probe for food in the bottom sediment. Its jaws are greatly protrusible, allowing it to capture buried prey.

Wikipedia contributors, Sixgill stingray; see linked history · CC BY-SA 4.0 . Plain-text lead excerpt, at most 180 words; no infobox or later sections Retrieved 2026-10-05T22:48:10.971319+00:00. This reference remains separate from the taxonomic record.

Identity & source status

Scientific name

Hexatrygon bickelli Heemstra & Smith, 1980

Name authority

Heemstra & Smith, 1980

Rank

species

Accepted status

accepted

Kingdom

Animalia

Phylum

Chordata

Class

Elasmobranchii

Order

Myliobatiformes

Family

Hexatrygonidae

Genus

Hexatrygon

Extinction status

Not supplied by this source

Source habitat flags: Marine: yes · Freshwater: no · Terrestrial: no. These do not form a complete habitat description.

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. parvphylumChondrichthyes
7. classElasmobranchii
8. subclassNeoselachii
9. infraclassBatoidea
10. orderMyliobatiformes
11. familyHexatrygonidae Heemstra & Smith, 1980
12. genusHexatrygon Heemstra & Smith, 1980
13. speciesHexatrygon bickelli Heemstra & Smith, 1980

Close classified relatives

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

Browse 1 records assigned to Hexatrygonidae.

Names & synonyms

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

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. Heemstra, P. C., & Smith, M. M. (1980). Hexatrygonidae, a new family of stingrays (Myliobatiformes: Batoidea) from South Africa, with comments on the classification of batoid fishes. Ichthyological Bulletin of the J. L. B. Smith Institute of Ichthyology, No. 43: 1–17. 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:3LHH5. Classification follows source parent identifiers. English common names may vary by region.