It was only in 2011 that a volunteer from the Western Australian Museum in Perth spotted the egg case in the museum archives among other egg cases. Despite being rediscovered just over a decade ago, it was only last April that the new species was listed in the Journal of Fish Biology as a new variety of demon catshark, Apristurus ovicorrugatus.
Identifying the shark species has been an exciting challenge, bringing experts together to “liaise with each other and talk with each other” said Will White, senior curator of the Australian National Fish Collection at the Commonwealth Scientific and Industrial Research Organisation (CSIRO), in an interview with the BBC. White explained that when the egg was originally retrieved, little attention was paid to its morphological features, and it was placed with other cases in the museum archives.
The egg cases from the 1980s were brought to light again when the single egg found by the volunteer was recovered along with other egg cases of the same type, all found at depths ranging from 410m to 504m underwater. Through efficient detective work, it was finally confirmed that a new species had indeed been discovered.
The morphology of the shark egg case is crucial in identifying the taxonomic classification to which the invertebrate belongs. Thus, the egg can reveal a story. By comparing the found egg with existing data in the database, the egg was narrowed down to belonging to the genus Apristurus. This determination was made based on the T-shaped ridges that formed the egg’s features. Furthermore, the developing embryo within the egg also indicated the genus through its hind fins form.
Apristurus ovicorrugatus is a type of demon catshark that resides 700m deep underwater. It specifically lays eggs in coral reefs, at depths dark enough to provide complete darkness. The egg cases are designed to support the shark’s development offering protection. This elusive species is not well known, particularly due to its resemblance to other species, which makes it difficult to pinpoint distinguishing features.
Currently, there are over 500 known shark species, and this number is increasing. White is currently working on another new species of catshark withing the same genus, Apristurus, but with different egg case ridging morphology. This species was caught off Queensland, Australia.
It is remarkable to note that the number of species within the genus is growing as new species are being discovered. In fact, over the past two decades, nine new species have come to light. However, the depth at which these species thrive limits information about the preferred substrate for egg deposition and attachment methodology. Additionally, the lack of information also means that less is known about the main function of the ridges that form the egg case.
Notably, this serves as a clear example that a museum display and a research paper alone are insufficient to represent what realistically exists underwater. Commercial fishing, ocean warming, and species evolution will always exert pressure on the development of new species. In light of these findings, it is crucial to continue exploring and studying the depths of our oceans to uncover the hidden diversity and understand the ecological dynamics that shape our marine ecosystem.
The Divers24 portal is currently the largest online medium treating diving in Poland. Since 2010 we have been providing interesting and important information from Poland and around the world on all forms of diving and related activities.
Contact us: firstname.lastname@example.org