Researchers report discovering four new species of giant, single-celled organisms on the seabed in the Pacific Ocean.
Scientists revealed two new genera and four novel species of giant single-celled xenophores (protozoans that relate to a group called the foraminifera) have been discovered at the bottom of the Pacific Ocean. ‘Moana’ – the sea in Hawaiian – has inspired the name Moanammina for one of the new genera, while the second has been named Abyssalia in recognition of its abyssal habitat.
The novel species were described based on morphology and genetic data, from specimens collected with the University of Hawaii Lu’ukai remotely operated vehicle on an expedition to the western Clarion Clipperton Zone (CCZ) aboard the RV Kilo Moana in 2018.
The seabed in this area is more than 4,500 meters deep.
“We were excited to find these beautiful new xenophyophores,” explained Andrew Gooday, professor at NOC and lead author of the recently published findings.
“It seemed appropriate to name one after ‘Moana,’ a Hawaiian word meaning ocean. Xenophyophores are one of the most common types of large organisms found on the CCZ abyssal plains, so the name of the second genus was chosen to reflect this.”
The CCZ occupies a vast swath of the Pacific Ocean with extensive deposits of polymetallic nodules on the seafloor and is intended for deepwater mining.
Similar to other types of foraminifera, xenophophors create shells made up of particles that they obtain from the encompassing environment. These are elaborate structures that can reach sizes of ten centimeters and sometimes even more.
Moanammina semicircularis sp. nov., the new species of the new genus, has been described as having a stalked fan-shaped shell, about 7.62 centimeters, and 8.89 wide.
Two other new species, Abyssalia foliformis sp. Nov. and Abyssalia sphaerica sp. Nov., have shells that resemble a flat sheet and an almost perfect sphere, respectively.
They are notable for being formed entirely of glass sponge spicules. The fourth new species is Psammina tenuis sp. nov., which has a fragile, thin, plate-shaped shell.
“These four new species and two new genera have increased the number of described xenophyophores in the CCZ abyss to 17 (22% of the global total for this group), with much more known but still undescribed,” said Gooday.
“This part of the Pacific Ocean is clearly a hotspot of xenophyophore diversity.”
According to reports, Moanammina semicircularis is genetically identical to another specimen discovered by scientists in 2017 in the Eastern CCZ.
Therefore, this study presented the first genetic confirmation of wide geographic ranges (at least 3,400 kilometers) for a species of abyssal xenophophore.