An international research team, led by the Complutense University of Madrid (UCM), has discovered a new species of kinorhynch, or mud dragon, in the South Orkney Trench, in the Antarctic Ocean, at a depth of 6000 meters. This finding significantly expands knowledge about the biodiversity of these animals in hadal environments, adding to a very small group of known species at these depths.
Kinorhynchs are small animals that range from 100 micrometers to 1 millimeter, forming part of the meiofauna, an essential animal community for the proper functioning of marine ecosystems. The study, published in Zoologischer Anzeiger, describes this new species in a very little-explored environment due to the technical difficulties involved. Until this discovery, only two species of kinorhynchs were known in hadal zones, so this finding increases the total knowledge of this group in these particular environments by 33%, according to the Complutense University.
Sampling was conducted in December 2019, dividing the sediment into layers one centimeter thick down to a depth of five centimeters, then extracting the animals from the substrate using a flotation method. The samples were dyed with a pigment for animals, and the kinorhynchs were separated by hand under a binocular microscope at the University of Southern Denmark.
For the identification and analysis of the new species, named Echionderes australis sp., optical microscopy and scanning electron microscopy were used, employing interactive keys and specialized literature. The results of this study have significant implications for the taxonomy of these small invertebrates, as well as for the understanding and conservation of deep marine ecosystems, concluded the researchers.
In addition to UCM, the work involved the University of Southern Denmark, the Federal University of Rio Grande (Brazil), the Japan Agency for Marine-Earth Science and Technology, and the French Institute for Research for the Exploration of the Sea.
