Capillary Tower

Mountainous capillary tower alongside bioships feeding from low orbit.^[7c]

Capillary towers, also called feeding towers^[6] or intestinal towers, are a key part of a Tyranid Hive Fleet's consumption cycle.^[5] These structures on a world's surface dock with questing Capillary Tubes of low-orbit bio-ships to pump the bio-gruel of Digestion Pools into the Hive Fleet's stomachs.^[11]

Overview

Tyranid feeding system; capillary towers and bioship feeding tubes.^[3]^[8]^[7a]

These stationary Tyranid bioforms may appear like plant-analogues, but they are just as aggressive as their more mobile bioforms. The towers extend tendrils that will absorb any flora or fauna that lack the ability to quickly exit the capillary tower's vicinity. They simultaneously filter the world's atmosphere, absorbing any microbes, flying fauna, or other organic matter to be gathered.^[2b]

Capillary towers can grow to reach the upper atmosphere (and beyond). Where they grow, Reclamation Pools then start to appear. The towers are linked to them via underground roots. Later, the towers link up with the sucking proboscis feeding tubes of hive ships in low orbit, which then pump the biomass upwards and distribute it to the waiting biovessels.^[1]

Consumption Process

Capillary Tubes and Digestion Pools^[11]

These plant-like growths are often seen sprouting across the landscape in the wake of a Tyranid invasion, often in the Tyranid's backlines. The nascent towers will eventually grow to monumental heights in the latter stages of a world's consumption,^[2c] like gigantic jagged fangs erupting from a world's crust.^[2a] Their fleshy, musclular bulk is held upright by durable mineral structures and flesh tethers.^[6] The feeding tower's ultimate role is to serve as a connection point for a bioship's feeding tubes that will then gorge on the consolidated biomass.^[2c]^[5] The feeding tubes are a multi-pronged system of proboscises twisted together that descend from consumption ships that themselves are tethered to larger bio-ships in orbit.^[5]

The biomass consolidated at these towers is collected by various Tyranid feeder beasts who, alongside their larger combat bioforms, throw bloated bodies into the reclamation pools at the base of a towers, being dissolved in digestive acids alongside their harvest of biomass. The towers can also spawn additional bioforms planetside, bolstering the invasion of a world.^[2a]

Once the Hive Fleet's feeding has concluded, the fleshy parts of the towers will be stripped from them, leaving behind the mineral structure that had held them aloft. This structure is durable and can keep portions of the feeding towers upright even without their musculature and flesh tethers. It is evident that reabsorption of the mineral structures is problematic enough for hive fleets to leave them behind on multiple consumed worlds, leaving behind only the lacy remains of feeding towers.^[6]

Dispersion

Capillary towers surround a bioship feeding tendril as it extracts aquatic biomass.^[7b]

Spores that can later become capillary towers are seeded by Tyranid bioforms as they burrow, such as Trygons and Mawlocs. The towers absorb any organism or organic matter they are in contact with, growing quickly from the ground. These towers are often seen in the Tyranid backlines and their biomass reserves are used to birth additional bioforms during a world's assault.^[2a] Their powerful metabolic filtration systems draw in all biomass,^[2c] causing the thinning air of a world to blow directly towards the largest nearby tower.^[5]

The capillary towers are capable of growing in the deepest of seas, able to sustain the pressure of the depths and the coldest of waters. As they grow the planet's tidal flow is altered by their powerful metabolic filtration systems, used to draw in all biomass.^[2c]

Vulnerability

Bioship feeding tube towers seen on day 4 of the Leviathan splinter fleets' invasion of Kadaku. The consumption stage has begun, and an Icarus Lascannon prepares to fire.^[3]

Enormous Capillary towers and feeding bioships typically marks the latter stages of a Tyranid invasion and death of a world. Large feeding towers and bio-ships deploying their feeding tubes typically marks Stage 3 "Consumption" and Stage 4 "Assimilation" of a Tyranid invasion.^[2c]

This typically marks the death of a world where the only recourse is exterminatus. However, it's also typically when bio-ships and hive ships are most vulnerable, having likely expended a significant amount of biomass in their initial assault. Destroying or damaging the Tyranid Hive Fleet (via exterminatus or other means) while it is feeding can potentially deny the hive fleet biomass to fuel to renew its assault. Destroying the towers or feeding tubes before the biomass reaches a bioship would deny the fleet valuable biomass to assimilate. Thus leaving the hive fleet as a whole, in a weaker state.^[2c]

This stage also provides an opportunity to destroy a synapse node creature aboard a bioship, whether by destroying the ship or via a Kill Team boarding the vessel to assassinate the link.^[2d] This would then lead to the Tyranid bioforms being thrown into disarray, becoming little more than beasts without the Hive Mind guiding the assault.^[5]

Gallery

Bio-ship feeding from a capillary tower.^[2c]
Consumption ships tethered to larger bio-ships consume biomass from enormous capillary towers jutting from a world's surface.^[10]
Capillary towers funnel biomass to the Hive Ships waiting in orbit.^[7a]