The Saharduin or Saharduins are a species of amphibian xenos that possess gills, erect posture, four webbed limbs and a long, finned tail.
Their troops, known as "Piscean Warriors," are armed with wave-bladed swords and rifles similar to Imperial Bolters, and carry backpacks connected by tubes to their gills, which presumably allow them to survive out of the water.
The White Scars Chapter is known to have fought against these dreaded aliens at some point during the 41st Millennium -- Scout-Sergeant Ultas Kholka spent a whole Terran year in the depths of Saharduin space during this engagement.
- Citadel Miniatures March 1987 mail order flyer
- Codex Imperialis (2nd Edition), pg. 90
- The Horus Heresy Book Seven: Inferno, pg. 81
- The Hunt for Voldorius (Novel) by Andy Hoare, Ch. 5