By Elsa B. Girard (ESR at Naturalis Biodiversity Center)

A new pet at Naturalis
To fill the hole left by the impossibility to go to the field in Indonesia in 2020, we decided to host special guests at Naturalis… One of the only living creatures at Naturalis, besides plants and humans: large benthic foraminifera! Yes, that’s right! Burger’s Zoo (Arnhem, the Netherlands) kindly offered us 2 kg of sediment from their large “homemade” Indo-Pacific coral reef aquarium full of tiny forams, amongst others. After sorting out the forams, we found two main species: Heterostegina depressa and Amphistegina sp..

The decalcification experiment
Forams are very well treated until they volunteer for science. In that case, they undergo bleaching at high temperature and bright light and are soaked in acidified seawater for decalcification. The goal of the experiment is to isolate their DNA in a clean way. Since large benthic forams host microalgae, which give them this brownish color, their DNA is highly contaminated with the symbiont genome. We now have a good protocol to decalcify forams, but we are still struggling in getting rid of their symbionts (see animation below). Once we succeed in bleaching the forams, we can obtain a cleaner DNA extract for long read sequencing!

Thousand thanks to Anouk Langerak (bachelor student, University of Applied Sciences, Leiden) for her great work in the lab with us!

Written by ESR: Elsa B. Girard

MSc in Geobiology and Paleobiology

Naturalis Biodiversity Center, Netherlands