Micropilina arntzi

Micropilina arntzi is a species of monoplacophoran, a superficially limpet-like marine mollusk. It is found off the coast of Antarctica. It has three pairs of gills.
Anatomy.
"Micropilina arntzi" has three pairs of gills, three pairs of nephridia ("kidneys"), six irregularly coiled intestinal loops, two pairs of oesophageal pouches, and no heart.