foraminiferal_diversity
Deep-sea foraminiferal diversity
Deep-sea floors represent one of the largest and most complex ecosystems                 on Earth but remain essentially unexplored. Th vastness and remoteness of this                 ecosystem make deep-sea sam pling dif?cult, hampering traditional taxonomic                 observations an diversity assessment. This is particularly true in the case of th                 deep-sea meiofauna, which largely comprises small-sized, fragile and                 dif?cult-to-identify metazoans and protists. Here, we intro duce an ultra-deep                 sequencing-based metagenetic approach to ex amine the richness of benthic                 foraminifera, a principal componen of deep-sea meiofauna. We used Illumina                 sequencing technolog to assess foraminiferal richness in 31 unsieved deep-sea                 sedimen samples from ?ve distinct oceanic regions. We sequenced an ex tremely short                 fragment (36 bases) of the small subunit ribosoma DNA hypervariable region 37f,which                 has been shown to accuratel distinguish foraminiferal species. In total, we obtained                 495,97 unique sequences that were grouped into 1,643 operational taxo nomic units,                 of which about half (841) could be reliably assigned t foraminifera. The vast                 majority of the operational taxonomic unit (nearly 90%) were either assigned to                 early (ancient) lineages o soft-walled, single-chambered (monothalamous)                 foraminifera o remained undetermined and yet possibly belong to unknown earl                 lineages. Contrasting with the classical view of multichambere taxa dominating                 foraminiferal assemblages, our work re?ects a unexpected diversity of monothalamous                 lineages that are as ye unknown using conventional micropaleontological observations                 Although we can only speculate about their morphology, the im mense richness of                 deep-sea phylotypes revealed by this study sug gests that ultra-deep sequencing can                 improve understanding o deep-sea benthic diversity considered until now as unknowabl                 based on a traditional taxonomic approach.
Deep-sea floors represent one of the largest and most complex ecosystems                 on Earth but remain essentially unexplored. Th vastness and remoteness of this                 ecosystem make deep-sea sam pling dif?cult, hampering traditional taxonomic                 observations an diversity assessment. This is particularly true in the case of th                 deep-sea meiofauna, which largely comprises small-sized, fragile and                 dif?cult-to-identify metazoans and protists. Here, we intro duce an ultra-deep                 sequencing-based metagenetic approach to ex amine the richness of benthic                 foraminifera, a principal componen of deep-sea meiofauna. We used Illumina                 sequencing technolog to assess foraminiferal richness in 31 unsieved deep-sea                 sedimen samples from ?ve distinct oceanic regions. We sequenced an ex tremely short                 fragment (36 bases) of the small subunit ribosoma DNA hypervariable region 37f,which                 has been shown to accuratel distinguish foraminiferal species. In total, we obtained                 495,97 unique sequences that were grouped into 1,643 operational taxo nomic units,                 of which about half (841) could be reliably assigned t foraminifera. The vast                 majority of the operational taxonomic unit (nearly 90%) were either assigned to                 early (ancient) lineages o soft-walled, single-chambered (monothalamous)                 foraminifera o remained undetermined and yet possibly belong to unknown earl                 lineages. Contrasting with the classical view of multichambere taxa dominating                 foraminiferal assemblages, our work re?ects a unexpected diversity of monothalamous                 lineages that are as ye unknown using conventional micropaleontological observations                 Although we can only speculate about their morphology, the im mense richness of                 deep-sea phylotypes revealed by this study sug gests that ultra-deep sequencing can                 improve understanding o deep-sea benthic diversity considered until now as unknowabl                 based on a traditional taxonomic approach.