Are there species smaller than 1 mm?
Related Experiment Video
Updated: May 9, 2026

Caenorhabditis Sieve: A Low-tech Instrument and Methodology for Sorting Small Multicellular Organisms
Published on: July 4, 2018
Axel G Rossberg1, Tim Rogers, Alan J McKane
1Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft NR33 0HT, UK. axel@rossberg.net
Abstract:
The rapid advance in genetic sequencing technologies has provided an unprecedented amount of data on the biodiversity of meiofauna. It was hoped that these data would allow the identification and counting of species, distinguished as tight clusters of similar genomes. Surprisingly, this appears not to be the case. Here, we begin a theoretical discussion of this phenomenon, drawing on an individual-based ecological model to inform our arguments. The determining factor in the emergence (or not) of distinguishable genetic clusters in the model is the product of population size with mutation rate-a measure of the adaptability of the population as a whole. This result suggests that indeed one should not expect to observe clearly distinguishable species groupings in data gathered from ultrasequencing of meiofauna.
Related Concept Videos
Cell Size
Surface Area
Cells can take in nutrients and water via diffusion through the plasma membrane itself or through specific channels in the membrane. The area of the membrane surrounding the cells limits the...
Phylogenetic Species Concept in Microbiology
What is a Species?
Bacterial Phylum Tenericutes
Imaging Biological Samples with Optical Microscopy
In optical microscopy, the specimen to be viewed is placed on a glass slide and clipped on the stage...
Conservation of Small Populations

