abstract |
Tardigrades are a phylum of enigmatic micrometazoans found all over the globe that
have been of scientific interest ever since they were discovered in the 18th Century.
Tardigrades are able to survive a range of stressful conditions that are too harsh, or
even lethal to most animals, by undergoing cryptobiosis. Their innate survival
mechanisms are very exciting to scientists looking for potential applications of their
biology to human industries. As tardigrade species become increasingly studied in the
lab, it is important to ensure they are correctly identified by taxonomy. Accurate
classification and identification of species is the only way to ensure that studies on
these animals conducted in separate parts of the world can inform each other and
remain valuable.
This study aimed to use integrative taxonomy to classify organisms of found
tardigrade populations. Integrative taxonomy refers to the use of a combination of
taxonomic techniques, typically morphological, molecular, and ecological, to classify
organisms more accurately, and has become increasingly used by taxonomists over the
past decade The use of multiple techniques allows researchers to gain more
understanding of the similarities and differences that exist between two organisms that
may not be captured by the use of a singular approach. Approximately 100 tardigrades
were isolated and imaged under a microscope from a range of substrates sampled
across 10 sites to search for primarily limno-terrestrial tardigrades of northern New
Jersey, USA including Drew University. 18S rRNA barcode sequencing was performed
on the photographed individuals. Complete sequences for these genes were assembled
for 5 distinct species that are described in the paper.
Two of the 18S rRNA sequences generated are slightly different from ones
available in GenBank, but most closely match Milnesium tardigradum and Ramazottius
oberhaeuseri. The remaining were identified as Minibiotus intermedius,
Paramacrobiotus tonollli and Diphascon pingue, of which the latter two have never been
described to occur in New Jersey before. Further investigations into the novel
sequences is recommended using alternate DNA barcodes that may yield more results
Research efforts to improve the understanding of biogeographic distributions of
tardigrades is extremely important in monitoring the sensitivity of these animals to
human-induced pressures.
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