The scientific community currently recognizes the existence (without counting fossils) of 551 species of sharks, 552 if one counts the recently described Apristurus ovicorrugatus. This deep-sea shark from the family of sciliorhinids (popularly, catfish, filefish or catfish) has gone unnoticed by humans until now and, in fact, its description has been pure serendipity, that is, a lucky discovery to which it has arrived accidentally, or almost accidentally, to be more precise.
The shark A. ovicorrugatus (scientists write it this way when the full name has already been mentioned above, to save space) has never been seen in the water and its knowledge dates back to 2011, when a group of experts observed some Shark eggs preserved in an Australian museum.
The external shape of these embryos drew so much attention that an investigation was launched, after which an identical specimen was located in a second museum and the description of the new species, now ratified with the publication of the results in the Journal of Fish Biology.
The work was carried out by ichthyologists from the CSIRO National Research Collections Australian National Fish Collection, Hokkaido University (Japan) and the Sorbonne Université (France).
The egg that led to the initiation of the investigation had crests and folds on its outside that were different from those known in similar cases, although they resembled those of the genus Apristurus. In addition, they were the only ones that had been found attached to the corals.
A decade later, two more cases of eggs with these same characteristics were identified, both housed in the Australian National Fish Collection, so the study was expanded. The authors began searching databases for Apristurus-type sharks sighted around the same areas where the eggs were found. This process led to some shark specimens kept in a museum that had never been accurately identified.
The research team then discovered that a misidentified female shark of this species was pregnant when she died, and that her body contained an egg that matched those found in the museum. The case was solved. She had put light on the dark, this time, on the museum shelves.
The group headed by William T. White includes an allegorical phrase in the title of its article presenting its results: "What came first, the shark or the egg?" explains that he has assigned the scientific name Apristurus ovicorrugatu to the new species in reference to the corrugated appearance of the case or external part of the egg.
The authors are now reviewing archives and samples from other museums in search of more specimens, without ruling out that in the future, by serendipity or not, living individuals of this species may be located and studied.