Black loosejaw

Open encyclopedia reference

Malacosteus niger, commonly known as the stoplight loosejaw, is a species of deep-sea fish. Some additional common names for this species include: northern stoplight loosejaw, lightless loosejaw, black loosejaw, and black hinged-head. It belongs to the family Stomiidae, or dragonfishes. It is among the top predators of the open mesopelagic zone, and inhabits the mesopelagic and bathypelagic zones. M. niger is a circumglobal species, which means that it inhabits waters ranging from the tropics to the subarctics. Not many studies have been conducted on its feeding habits, but recent research suggests that M. niger primarily feed on calanoid copepods which is a form of zooplankton. Indeed, it appears that M. niger primarily prey on zooplankton despite its apparent morphological adaptations for the consumption of relatively large prey. Another unique adaptation for this species is its ability to produce both red and blue bioluminescence. Most deep sea species aren't capable of producing red bioluminescence. This is advantageous because most other species cannot perceive red light, therefore allowing M. niger to camouflage part of itself to its prey and predators.

Wikipedia contributors, Malacosteus niger; see linked history · CC BY-SA 4.0 . Plain-text lead excerpt, at most 180 words; no infobox or later sections Retrieved 2026-10-05T04:09:53.842944+00:00. This reference remains separate from the taxonomic record.

Identity & source status

Scientific name

Malacosteus niger Ayres, 1848

Name authority

Ayres, 1848

Common name

Black loosejaw

Rank

species

Accepted status

accepted

Kingdom

Animalia

Phylum

Chordata

Class

Teleostei

Order

Stomiiformes

Family

Stomiidae

Genus

Malacosteus

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. parvphylumOsteichthyes
7. gigaclassActinopterygii
8. superclassActinopteri
9. classTeleostei
10. orderStomiiformes
11. familyStomiidae Bleeker, 1859
12. subfamilyMalacosteinae Gill, 1890
13. genusMalacosteus Ayres, 1848
14. speciesMalacosteus niger Ayres, 1848

Close classified relatives

These entries share the source’s genus, Malacosteus. They are not necessarily the closest relatives established by molecular evidence.

Browse 236 records assigned to Stomiidae.

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. Ayres, W. O. (1848). [On a very curious fish.]. Proceedings of the Boston Society of Natural History, v. 3 (1848–1851): 69–70. 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:3XKZC. Classification follows source parent identifiers. English common names may vary by region.