They are relatives of octopuses and cuttlefish but look like snails and the expression ‘living fossil’ is sometimes used to indicate that they are a group of species that have remained relatively unchanged for millions of years.
In fact, nautiluses (nautiloides) are a group of marine mollusks better known for the extensive fossil record that exists of various species of them, than for the living animals studied in recent years.
The taxonomy of this group has been the subject of debate, but until now many experts considered that only three to five species of nautilus were kept alive. Scientific knowledge has changed and there may be three more species that have survived to this day.
For years, one of the main methods for defining nautilus species was by looking at their shells (shapes and patterns). Now, genetic work has made it possible to refine the classification.
And one of the results of the most recent studies is the proposed classification of three new species, based on specimens found in the Coral Sea (western Pacific Ocean, off the northeastern coast of Australia) and the South Pacific region. .
The authors of the research have introduced the new species Nautilus samoaensis (from American Samoa), Nautilus vitiensis (from Fiji) and Nautilus vanuatuensis (from Vanuatu) in an article published in the journal ZooKeys (January 25, 2023).
The formal naming of these three new species is timely considering new and recently published information on genetic makeup, geographic occurrence, and new morphological characters, including carapace color patterns and soft-part morphology of the hood, he explains. the study’s author team, led by Gregory Barord, a researcher in the Department of Marine Sciences at Central Campus, Des Moines (United States).
In addition to improving scientific knowledge, the discovery and description of the three new species “will help in the management of these potentially endangered animals,” the team states in the abstract of their paper presenting the results,
The authors highlight that the species now described are separated not only by their genetic and physical characteristics, but also by the biogeographic barriers of the distance of their populations (separated by at least 200 km) and depth of their ecosystems, which they cannot overcome. the 800 meters.
