Sandworm (Dune) - Sandworm Life Cycle

Sandworm Life Cycle

Herbert notes in Dune that microscopic creatures called sand plankton feed upon traces of melange scattered by sandworms on the Arrakeen sands. The sand plankton are food for the giant sandworms, but also grow and burrow to become what the Fremen call Little Makers, "the half-plant-half-animal deep-sand vector of the Arrakis sandworm."

Their leathery remains previously having "been ascribed to a fictional "sandtrout" in Fremen folk stories," Imperial Planetologist Pardot Kynes had discovered the Little Makers during his ecological investigations of the planet, deducing their existence before he actually found one. Kynes determines that these "sandtrout" block off water "into fertile pockets within the porous lower strata below the 280° (absolute) line," and Alia Atreides notes in Children of Dune that the "sandtrout, when linked edge to edge against the planet's bedrock, formed living cisterns." The Fremen themselves protect their water supplies with "predator fish" who attack invading sandtrout. Sandtrout can be lured by small traces of water, and Fremen children catch and play with them; smoothing one over the hand forms a "living glove" until the creature is repelled by something in the "blood's water" and falls off.

The sandtrout ... was introduced here from some other place. This was a wet planet then. They proliferated beyond the capability of existing ecosystems to deal with them. Sandtrout encysted the available free water, made this a desert planet ... and they did it to survive. In a planet sufficiently dry, they could move to their sandworm phase. — Leto Atreides II, Children of Dune

The sandtrout are described as "flat and leathery" in Children of Dune, with Leto Atreides II noting that they are "roughly diamond-shaped" with "no head, no extremities, no eyes" and "coarse interlacings of extruded cilia." They can find water unerringly, and squeezing the sandtrout yields a "sweet green syrup." When water is flooded into the sandtrout's excretions, a pre-spice mass is formed; at this "stage of fungusoid wild growth," gasses are produced which result in "a characteristic 'blow,' exchanging the material from deep underground for the matter on the surface above it." After exposure to sun and air, this mass becomes melange.

Kynes' "water stealers" die "by the millions in each spice blow," and may be killed by even a "five-degree change in temperature." He notes that "the few survivors entered a semidormant cyst-hibernation to emerge in six years as small (about three meters long) sandworms." A small number of these then emerge into maturity as giant sandworms, to whom water is poisonous. A "stunted worm" is a "primitive form ... that reaches a length of only about nine meters." Their drowning by the Fremen makes them expel the awareness-spectrum narcotic known as the Water of Life.

While sandworms are capable of eating humans, the latter do contain a level of water beyond the preferred tolerances of the worms. They routinely devour melange-harvesting equipment — mistaking the mechanical rhythm for prey — but they only seem to derive actual nutrition from sand plankton and smaller sandworms. Sandworms will not attack sandtrout.