Stomias boa

Stomias boa
Preserved Specimen
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Stomiiformes
Family: Stomiidae
Genus: Stomias
Species:
S. boa
Binomial name
Stomias boa
(Risso, 1810)
Synonyms[2]
  • Esox boa Risso, 1810
  • Stomias bonapartei Fowler, 1912
  • Stomias elongatus atlanticus Pappenheim, 1912
  • Stomiasunculus barbatus Kaup, 1860
S. boa ferox
S. boa boa
S. boa boa: the hexagonal areas above the photophores are visible.[3]

Stomias boa, also known as the boa dragonfish, scaly dragonfish, dragon-boa or boa scaly dragonfish, is a species of deep-sea fish in the family Stomiidae.[4][5][6][3][7] It is found at great depths worldwide in tropical to temperate oceans but is absent from the northern Pacific and northwest Atlantic Oceans.

Taxonomy

Three subspecies were previously recognised:

These and two others have been elevated to species.[8]

  • Stomias boa boa (Risso, 1810) is now Stomias boa (Risso, 1810)
  • Stomias boa colubrinus Garman, 1899 is now Stomias colubrinus Garman, 1899
  • Stomias boa danae Ege, 1933 is now Stomias danae Ege, 1933
  • Stomias boa ferox Reinhardt, 1842 is now Stomias ferox Reinhardt, 1842
  • Stomias boa gracilis Garman, 1899 is now Stomias gracilis Garman, 1899

Description

Stomias boa has an elongated body and small head;[9] it is up to 32.2 cm (1.06 ft) in length, black underneath and iridescent silver on its flanks, with a barbel that has a pale stem, dark spot at base of bulb and three blackish filaments.[10][11] It has six rows of hexagonal areas above a lateral series of large photophores.[12] The dorsal and anal fins are opposite each other, just anterior to the caudal fin.[13]

The mouth has a protuberant lower jaw and sharp, pointed teeth. There is a large fleshy barbel projecting from the chin with a pale stalk, a dark spot at the base of the bulb and a dark filament. The dorsal fin has no spines and 17 to 22 soft rays and the anal fin has 18 to 22 soft rays. The dorsal and anal fins are positioned on the slender caudal peduncle and the caudal fin is forked. The skin is covered in small hexagonal scales. Like many fish of deep oceans, it has large eyes and is transparent and silvery in appearance with iridescent speckles.[14][15][16]

Distribution and habitat

Stomias boa is mesopelagic and bathypelagic, living at depths of 200–2,173 m (656–7,129 ft) in seas worldwide in a band 20°–45° S,[17][18][19] particularly off the Atlantic coast of North America, in the western Mediterranean, the west coast of Africa as far south as Mauritania and southern Africa from Angola to the Cape of Good Hope. On the other side of the Atlantic it is found from the Northwest Territories of Canada to Argentina. It is also known from Chile and the sub-Antarctic region of the Indian Ocean south to Heard Island.

The related S. colubrinus is most common off the Congo coast and the northwest coast of South America.[20][21]

It usually inhabits waters deeper than 1,000 metres (3,300 ft) in the daytime but migrates upwards towards the surface during the night.[14]

Diet

Stomias boa eats midwater fishes and crustaceans; it rises to near the surface to feed at night.[11]

Ecology

It is itself preyed on by the deepwater hakes Merluccius paradoxus and Merluccius capensis, the blackmouth catshark Galeus melastomus and the swordfish Xiphias gladius.[14]

Stomias boa boa has large light-producing photophores behind the eyes and other smaller ones scattered across the body in a geometrical pattern, mostly on the ventral surface.[22] Special organs near the eyes detect the amount of illumination in the surrounding water and this enables the fish to adjust the amount of light its photophores emit. The bioluminescence can be turned on and off at will and may confuse potential predators.[15] Other species of fish emit light in a similar way, and the particular arrangement of photophores in the scaly dragonfish permits individuals to identify other fish of the same species.[15]

Reproduction

Stomias boa is oviparous; its larvae are 9–44 mm (0.35–1.73 in) in length.[23]

References

  1. ^ Harold, Anthony (May 22, 2013). "IUCN Red List of Threatened Species: Stomias boa". IUCN Red List of Threatened Species – via www.iucnredlist.org.
  2. ^ "WoRMS - World Register of Marine Species - Stomias boa (Risso, 1810)". www.marinespecies.org.
  3. ^ a b Coad, Brian W.; Reist, James D. (January 1, 2018). Marine Fishes of Arctic Canada. University of Toronto Press. ISBN 9781442647107 – via Google Books.
  4. ^ "Boa Scaly Dragonfish, Stomias boa (Risso, 1810)".
  5. ^ Institution, Smithsonian (November 3, 1895). "Smithsonian Contributions to Knowledge". Smithsonian Institution – via Google Books.
  6. ^ Günther, Albert C. L. G. (November 3, 1864). "Catalogue of the Fishes in the British Museum: V". order of the Trustees – via Google Books.
  7. ^ Nations, Food and Agriculture Organization of the United (August 1, 2020). Identification guide to the mesopelagic fishes of the central and south east Atlantic Ocean. Food & Agriculture Org. ISBN 9789251330944 – via Google Books.
  8. ^ "Stomias boa (Risso, 1810)". WoRMS. World Register of Marine Species. Retrieved 2023-11-29.
  9. ^ Heessen, Henk J. L.; Daan, Niels; Ellis, Jim R. (September 1, 2015). Fish atlas of the Celtic Sea, North Sea, and Baltic Sea: Based on international research-vessel surveys. Wageningen Academic Publishers. ISBN 9789086868780 – via Google Books.
  10. ^ "Marine Species Identification Portal : Stomias boa". species-identification.org.
  11. ^ a b "Stomias boa, Boa dragonfish". www.fishbase.se.
  12. ^ "Stomias boa | NBN Atlas". species.nbnatlas.org.
  13. ^ "Stomias boa". fishesofaustralia.net.au.
  14. ^ a b c Papasissi, Christine. "Stomias boa boa (Risso, 1810)". FishBase. Retrieved 2013-06-18.
  15. ^ a b c Mojetta, Angelo (1996). Mediterranean Sea: Guide to the Underwater Life. Swan Hill Press. pp. 75–76. ISBN 9781853108129.
  16. ^ Mark McGrouther (2013-05-17). "Boa Scaly Dragonfish, Stomias boa (Risso, 1810)". Australian Museum. Retrieved 2013-06-19.
  17. ^ "Zoologica". New York Zoological Society. November 3, 1928 – via Google Books.
  18. ^ Smith, Margaret M.; Heemstra, Phillip C. (December 6, 2012). Smiths' Sea Fishes. Springer Science & Business Media. ISBN 9783642828584 – via Google Books.
  19. ^ "Stomias boa boa". www.gbif.org.
  20. ^ "Stomias boa colubrinus Garman, 1899 - Ocean Biodiversity Information System". obis.org.
  21. ^ "WoRMS - World Register of Marine Species - Stomias boa colubrinus Garman, 1899". www.marinespecies.org.
  22. ^ Gibbs, Robert H. (1969). "Taxonomy, sexual dimorphism, vertical distribution, and evolutionary zoogeography of the bathypelagic fish genus Stomias (Stomiatidae)". Smithsonian Contributions to Zoology. 31 (31): 1–25. doi:10.5479/si.00810282.31. hdl:10088/5259.
  23. ^ "Collected Reprints". The Center. November 3, 1987 – via Google Books.

Further reading

  • Tony Ayling & Geoffrey Cox, Collins Guide to the Sea Fishes of New Zealand, (William Collins Publishers Ltd, Auckland, New Zealand 1982) ISBN 0-00-216987-8