In the abyssal depths of the Pacific Ocean, scientists have made a fascinating discovery that could shed light on some of the most enigmatic creatures of the deep sea. Researchers, led by Romain Gastineau from the Institute of Marine and Environmental Sciences at the University of Szczecin in Poland, have uncovered mitochondrial genomes associated with xenophyophores, a type of giant single-celled organism found in the Clarion-Clipperton Zone. This area, stretching between Hawaii and Mexico, is known for its rich polymetallic nodule deposits, making it a hotspot for deep-sea mining interests.
Xenophyophores are a type of benthic foraminifera, which are single-celled organisms that build intricate shells from particles they find in their environment. These creatures are a significant part of the deep-sea ecosystem, but their biology remains poorly understood. The recent study, published in the journal ‘Frontiers in Marine Science’ (which translates to ‘Frontiers in Marine Science’ in English), has managed to sequence mitochondrial genomes from two xenophyophore specimens, providing new insights into their genetic makeup.
The researchers obtained a circular mitochondrial genome of approximately 25 kilobases from both specimens. These genomes share similarities with other Retaria, a group of single-celled organisms to which xenophyophores are related. One of the specimens also yielded a complete cluster of nuclear rRNA genes, a first for xenophyophores. Additionally, the researchers found another full cluster of rRNA likely belonging to Endomyxa parasites within both specimens.
“Although the agglutinated nature of xenophyophores currently prevents a definitive conclusion, the mitogenomes obtained may represent the first to be obtained from those foraminifera,” Gastineau explained. The study highlights the need for further research to properly ascribe these genomes to their host organism and to understand the nature of the possibly parasitic Rhizaria associated with the xenophyophores.
For the maritime and deep-sea mining sectors, this research could have significant implications. Understanding the biology of xenophyophores and their associated organisms is crucial for assessing the potential impacts of deep-sea mining activities. The Clarion-Clipperton Zone is rich in polymetallic nodules, which are valuable for their high concentrations of metals like manganese, nickel, cobalt, and copper. As interest in deep-sea mining grows, so does the need for comprehensive environmental impact assessments.
This genetic research could provide valuable data for such assessments, helping to ensure that mining activities are conducted in a way that minimizes harm to deep-sea ecosystems. Moreover, the discovery of new genetic material could open up opportunities for bioprospecting, the exploration of biological resources for potential commercial applications. This could include the development of new pharmaceuticals, biofuels, or other biotechnological products.
In the meantime, the findings serve as a reminder of the vast and largely unexplored world that lies beneath the ocean’s surface. As Gastineau puts it, “Deeper enquiries are required in order to properly ascribe these genomes to their host organism and to clarify the nature of the possibly parasitic Rhizaria associated with the xenophyophores.” This research is a step towards unraveling the mysteries of the deep sea, but there is still much more to discover.