''Bathysidus pentagrammus'', the five-lined constellation fish, is a

hypothetical species Several species have been assumed to exist, but due to a lack of physical evidence they can only be regarded as potential species. Hypothetical species are usually believed to be extinct. They have caused confusion, as they may have been a separat ...

of fish that was described by

William Beebe Charles William Beebe ( ; July 29, 1877 – June 4, 1962) was an American natural history, naturalist, ornithologist, marine biologist, entomologist, explorer, and author. He is remembered for the numerous expeditions he conducted for the New Y ...

on 11 August 1934, being spotted by the biologist as he descended to a depth of 580 metres (1900 feet) off the coast of

Bermuda Bermuda is a British Overseas Territories, British Overseas Territory in the Atlantic Ocean, North Atlantic Ocean. The closest land outside the territory is in the American state of North Carolina, about to the west-northwest. Bermuda is an ...

Background

The "

bathysphere The ''Bathysphere'' () was a unique spherical deep sea, deep-sea submersible which was unpowered and lowered into the ocean on a cable, and was used to conduct a series of dives off the coast of Bermuda from 1930 to 1934. The ''Bathysphere'' wa ...

" was a new invention, being a rounded steel enclosure with space for two people, a thick external hull, and a single window, in diameter. Maneuverability was solely dependent on the ship it was tethered to. Beebe had no camera with him and instead described the species in detail to Else Bostelmann, an artist who proceeded to illustrate his findings.

Encounter

The fish was seen in solitude. It was described by Beebe as resembling a

surgeon In medicine, a surgeon is a medical doctor who performs surgery. Even though there are different traditions in different times and places, a modern surgeon is a licensed physician and received the same medical training as physicians before spec ...

butterflyfish The butterflyfish are a group of conspicuous tropical ocean, marine fish of the family Chaetodontidae; the bannerfish and coralfish are also included in this group. The approximately 129 species in 12 genera are found mostly on the reefs of the ...

. It was disc-like in appearance, with a 12 cm high and 15 cm across. Its fins were continuous and vertical; its eyes large. Bebe was intrigued by this fish's striking bioluminescence, which he described in the book ''Half Mile Down'': "along the sides of the body were five unbelievably beautiful lines of light ... each line was composed of a series of large, pale yellow lights, and every one of these was surrounded by a semicircle of very small, but intensely purple photophores." Explicitly impressed with its luminescence, Beebe assigned the fish a taxonomic name, ''Bathysidus pentagrammus''. When translated, it roughly means "five-lined star of the depths". He then states that "in his memory it will live throughout his life as one of the loveliest things he has ever seen."

Status of existence

Of the five new fish described by Beebe during the Bathysphere dives, none of them were confirmed to exist. His colleague Otis Barton, who descended with him in the submersible, attested he had also seen them. Ichthyologist Carl Hubbs has proposed that the creature encountered by Beebe was not a fish at all, but rather a

ctenophore Ctenophora (; : ctenophore ) is a phylum of marine invertebrates, commonly known as comb jellies, that inhabit sea waters worldwide. They are notable for the groups of cilia they use for swimming (commonly referred to as "combs"), and they ar ...

, or "comb jelly". He proposed that the distortion caused by the small viewing window could have caused the comb jelly to appear narrower and cause its distinctive luminous lines to have been intensified.

References

{{Taxonbar, from=Q100451238 Aquatic cryptids Controversial fish taxa Fish described in 1934

Background

Encounter

Status of existence

See also

References