Foraminifera are unicellular organisms that occur mainly in the sea and have an external limestone skeleton. Species identification is often very difficult, because it is not clear whether an individual has a different shape because it lives in a different environment, for example in deep waters, or whether it relates to the characteristics of the species. For example, these organisms can look almost the same yet differ genetically, or have the same genes and look completely different.
How do appearance and genes relate to each other? Naturalis researchers looked at the genus Amphisorus. Various specimens were collected in Australia and Indonesia and studied by CT scan. These are 3D scans that show many details.
New varieties
These tests allow you to obtain a detailed picture of foraminifera. Four different external forms of Amphisorus are found. When the researchers looked at the foraminifera DNA, they also found small differences in this. Hence differences in appearance can also be demonstrated in DNA. When the researchers wanted to link the newly found specimens to the existing Amphisorus species, they were unable to properly relate them to the existing species, as they did not fit the descriptions well. “The combination of a different appearance and a different genotype makes it plausible that we are dealing with different types of Amphisorus. But for the time being, we have refrained from formally describing the new species, because we first want to study more samples from different regions and look at a greater number of genes,” As says Jan Machcher, Naturalis foraminifera expert.
Future vision
“We think many of the species have not been found or described yet,” says Jan Maker. It is now used in what is called “biological monitoring” in marine ecosystems. This is the monitoring of certain species that are very sensitive to changes in the environment. “More knowledge of biodiversity, distribution and ecology in foraminifera will make it easier to use these species for biomonitoring in the future,” said Maker.
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Text: Renée Zijlmans, Natural Biodiversity Center
Foto’s: Willem Renema & Jan Macher, Center for Natural Biodiversity
