Malpighian tubule

noun1

1. •
   A tubule that extends from the alimentary canal to the exterior of the organism, excreting water and wastes in the form of solid nitrogenous compounds. Found in certain insects, arachnids, myriapods and tardigrades.

   • The fruit fly's malpighian tubules, which act like a kidney, have a daily rhythm[…]. — 1997