Five-lined constellationfish

Five-lined constellationfish The five-lined constellation fish drawn by Else Bostelmann for Beebe, who reported seeing a solitary specimens. Classification Osteichthyes Proposed scientific names Bathysidus pentagrammus (Beebe, 1934) Other names Sea reported Atlantic Ocean First reported 1934 Prominent investigators • William Beebe

The five-lined constellationfish (Bathysidus pentagrammus) was a cryptid deep sea fish seen twice, off Bermuda in the Atlantic Ocean, during a bathysphere dive by William Beebe on 11 August 1934. Although he assigned it a taxonomic name, Beebe did not attempt to classify it.

Description

The constellationfish resembled a butterflyfish (family Chaetodontidae) or surgeonfish (family Acanthuridae) in form, with a narrow roundish body 5 in (12 cm) by 6 in (15 cm) in dimensions, continuous vertical fins, and a large eye. It was distinguished mainly by its bioluminescence, which Beebe found strikingly beautiful: "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."

Sightings

1934

From 1930 to 1934, Beebe and his colleague Otis Barton (1899 – 1992), based on Nonsuch Island in Bermuda, performed several pioneering deep sea dives in a bathysphere, an unpowered submersible designed by Barton. These record-setting dives allowed them to observe deep sea life alive for the first time. During a record-setting dive on 11 August 1934, Beebe observed this fish at a depth of 1,900 ft (579 m), during the descent. At the time of the sighting, he described it by telephone to his colleague Gloria Hollister (1900 – 1988) at the surface, as...

“

... a 5 by 6 inch fish with 4 or 5 lines of lights, yellow, with purple circles, 2 lines very distinctly curved up above middle line and 2 more curved below. More about it when I come up. Remind me. It disappeared by turning head on. New fish!

”

Beebe subsequently described this fish in greater detail in a scientific article giving it a binomial name, and in his book Half Mile Down (1934), both publiished within the same year.

“

A small school of luminous fish had just passed, when, fortunately at a moment of suspension, came a new and gorgeous creature. I yelled for continuance of the stop, which was at 1900 feet, and began to absorb what I saw; a fish almost round, with long, moderately high, continuous, vertical fins; a big eye, medium mouth, and small pectoral fins. The skin was decidedly brownish. We swung around a few degrees to port, bringing the fish into the dark blue penumbra of the beam, and then I saw its real beauty. Along the sides of the body were five unbelievably beautiful lines of light, one equatorial, with two curved ones above and two below. 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. The fish turned slowly and, head on, showed a narrow profile. If It were at the surface and without lights I should, without question, have called it a butterflyfish (Chaetodon) or a surgeonfish (Acanthurus). But this glowing creature was assuredly neither, unless a distant relation, adapted for life at three hundred fathoms. My name for it is Bathysidus pentagrammus, the Five-lined Constellation fish. In my memory it will live throughout the rest of my life as one of the loveliest things I have ever seen.

”

Theories

Beebe did not attempt to classify Bathysidus pentagrammus, beyond cautiously speculating that it could be a distant deep sea relation of the butterflyfish (family Chaetodontidae) or the surgeonfish (family Acanthuridae), both of which it resembled. Knowing there would likely be no second chances to describe most fish seen during his bathysphere dives, Beebe chose to assign names to the most distinctive of them: the constellationfish, giant dragonfish (Bathysphaera intacta), pallid sailfin (Bathyembryx istiophasma), three-starred anglerfish (Bathyceratias trilynchus), and abyssal rainbow gar. His memories of these fish were verified by Barton, and illustrations by Else Bostelmann, showing only characteristics of which he was certain, acted in lieu of physical holotypes. Due to the circumstances of his observations, the absence of type specimens, and the lack of corroboration by later sightings, the validity of Beebe's "abyssal fishes" have been question, and he has been accused of inventing or misinterpreting them. Ichthyologist Carl Hubbs (1894 – 1979) took particular issue with the constellationfish and the giant dragonfish. He argued that what Beebe interpreted as a fish was really a bioluminescent ctenophore, or comb jelly, "whose lights were beautified" and distorted by the mist of Beebe's breath on the bathysphere window. However, Bathysidus pentagrammus continues to appear on taxonomic lists.