Devil cat shark
For more than a decade, Australian scientists have puzzled Australian scientists with a strange unidentified shark egg, but now they have discovered that the eggs belong to a new species: the devil cat shark.
An unidentified shark egg discovered off Australia's Kimberley coast in 2011 recently helped researchers identify a new species of shark. The newly discovered sharks have distinctive white eyes, which scientists say are rare among deep-sea sharks, which could provide a better understanding of how sharks evolved.
According to a report by the Australian Broadcasting Corporation (ABC), the search for the identity of the manta catshark is particularly lengthy and frustrating for scientists at Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO).
Will White, senior curator of CSIRO's Australian National Fish Collection, said: "It's interesting because we often have the idea that something could be a new species, but it's going to take a long time to fix that and compare it to other species. ”
Part of the difficulty, Weir said, is that researchers don't have real animals to study. Instead, they found a small batch of unidentified shark eggs in 1989 and a similar egg in 2011 when Brett Human, then a researcher who volunteered at the Museum of Western Australia.
These eggs are markedly different from those of most sharks in that they have strong T-shaped ridges that, although unique among Australian-laying sharks, are only found in another shark.
T-shaped ridge of the devil catshark egg sheath
Reiter discovered the unique eggs and linked them to the 1989 collection, but he could only identify them as belonging to the genus Aprist, and he was unable to determine their species.
Will told Life Science: "These egg sheaths have very distinctive longitudinal ridges on the surface with a T-shaped cross-section. Only another species in the world has been found to have this form of bulge, which is a completely different genus. ”
Will described the journey to identify new species as "frustrating", but he and his colleagues made a major breakthrough in combing through the archives of Australia's National Fish Collection, where a similar specimen of the genus Apriste shark was found in the same area as the eggs, wrongly identified as a Chinese lighttail shark. It is a female shark that happens to be carrying eggs that match those found in 2011.
Will said: "Fortunately, the female specimen we found contained an identical ridged egg sheath, confirming our suspicions. ”
Fortunately, the female shark became pregnant, and the researchers found a late embryo in one of the egg sheaths.
With the unraveling of the mystery of the shark egg incident and the identification of the genus Aprist, researchers are finally able to get a more complete picture of this manta cat shark.
The devil catshark is one of the most diverse shark genera in the world, with about 40 known species, but the Apriest shark genus is particularly unique for its glowing white eyes.
Late embryos found in devil catshark eggs
Will said: "Usually, the eyes of the devil catshark are always dark, either dark green or black. White iris has only been found in another deep-water shark, a mid-swimming shark from New Caledonia and Papua New Guinea. It must have evolved for some particular reason, not just in a species, but in a group of species. ”
Will added: "This certainly opens up a research question about different evolutionary pathways that we don't take into account in this group." ”
The new manta cat shark was found at a depth of more than 700 meters on the seabed, where it spawns on top of coral. As Will explains, because they live in deep sea, these sharks are not often observed.
"If you look at the coastline, it's usually quite steep, it drops quickly, and they're relatively narrow in depth," Weir said. They may spawn in a habitat where they spawn on a specific coral species. ”
A similar but distinctive cat shark has previously been spotted on the other side of the country, just off the Gold Coast. Will believes the new discovery helped his team connect the two species.
Weir added: "We know very little about Australia's deep-water marine biota. He hopes to make more discoveries in the coming years.