CeDAMar Report Nina Rothe

Report for the CeDAMar grant of the taxonomist exchange program from Nina Rothe, National Oceanography Centre, Southampton, United Kingdom, October-December 2007

The objective of my stay at the University of Geneva was the analysis of SSU rDNA gene sequences from Weddell Sea gromiids that were collected during the 2005 ANDEEP III Expedition. Thus far, a few species are known from shallow water and only two species have been described from the deep sea, Gromia sphaerica (Gooday et al., 2000) and Gromia pyriformis (Gooday and Bowser, 2005). Therefore, the ANDEEP III samples represent one of the most important collections of undescribed deep-sea gromiids.

Thus far, I identified thirteen distinct morphotypes of these giant, organic-walled protozoans from the Weddell Sea based on detailed morphological descriptions, which form the basis of my PhD project at the National Oceanography Centre in Southampton. In the course of my two months stay in Geneva, I aimed to characterise different morphospecies at the molecular level by extracting DNA from frozen samples and undergoing Polymerase Chain and Reactions using Gromia specific primers that were designed during an earlier study on Arabian Sea gromiids in 2005 (Aranda da Silva et al., 2005).  The Molecular Systematics Group of the University of Geneva led by Prof. Jan Pawlowski provided all the modern equipment and expertise that was necessary for the analyses.

Preliminary results confirm the identification of at least three distinct species of Gromia based on molecular criteria including a novel morphotype in which the organic test is enclosed within an agglutinated case. Further analysis will give new insight into the evolutionary relationships between gromiid species from a region where this group was previously completely unknown, as well as between species living in widely separated regions.

I am very grateful to my supervisors Prof. Andrew Gooday and Dr. Alan Hughes for all their help and advice, as well as to Prof. Jan Pawlowski, José Fahrni, and Fabien Burki from the Molecular Systematics Group at the University of Geneva for their generous support and patience. I would also like to thank CeDAMar for awarding me the taxonomist exchange grant, which made this invaluable experience possible.

Nina Rothe
PhD student
Systematics and Biogeography of Antarctic Deep-Sea Gromiids
DEEPSEAS Benthic Biology Group

National Oceanography Centre, Southampton
Waterfront Campus, European Way,
Southampton, SO14 3ZH
United Kingdom