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Bipolar gene flow in deep-sea benthic foraminifera
J Pawlowski1, J Fahrni, B Lecroq
1Department of Zoology and Animal Biology, University of Geneva, Sciences III, 30, Quai Ernest Ansermet, CH 1211 Genève 4, Switzerland. jan.pawlowski@zoo.unige.ch
Molecular Ecology
|August 30, 2007
Summary
Deep-sea foraminifera exhibit surprisingly wide genetic similarities across vast distances, challenging previous biodiversity estimates. This suggests a more globally distributed deep-sea fauna than anticipated.
Area of Science:
- Marine Biology
- Deep-Sea Ecology
- Molecular Genetics
Background:
- The deep-ocean floor harbors diverse habitats, yet global diversity assessment is hindered by limited data on species' geographical ranges, especially genetic information.
- Benthic foraminifera are key components of deep-sea meiofauna, but their distribution patterns remain poorly understood.
Purpose of the Study:
- To investigate the geographical distribution and genetic diversity of deep-sea benthic foraminifera.
- To assess if deep-sea species exhibit wide ranges, contrasting with shallow-water organisms.
Main Methods:
- Molecular analysis of nuclear ribosomal RNA genes from deep-sea foraminifera populations.
- Comparison of genetic similarity between Arctic and Antarctic populations of selected species.
Main Results:
- High genetic similarity was found between Arctic and Antarctic populations of three common deep-sea foraminiferal species (Epistominella exigua, Cibicides wuellerstorfi, Oridorsalis umbonatus), spanning up to 17,000 km.
- These findings contrast with the significant cryptic diversity typically observed in shallow-water marine organisms.
Conclusions:
- The broad distribution of these deep-sea foraminifera supports the hypothesis of global distribution for small eukaryotes.
- Deep-sea biodiversity may be lower on a global scale than current estimates suggest, necessitating a re-evaluation of deep-sea ecosystem diversity.
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