The Tyranid fleet moved differently from those of other species. It manipulated gravity to propel itself, so there were no long ion engines or flames trailing behind it.
Combined with the bio-ships' exceptional control over their cells, which allowed them to change the color of their carapaces and their body temperature, this let them travel undetected.
This was the Tyranids' stealth mode.
In stealth mode, the Swarm Consciousness ordered the Tyranid Fleet to close rapidly on the human fleet while releasing vast numbers of suicide locusts to destroy human aircraft, probes, and other reconnaissance units.
Without these eyes, the accuracy of the human warships' long-range guns and Nova Cannons dropped sharply, allowing the Tyranid Fleet to close even faster.
Soon, the fleets of the Imperium of Man and the Tyranids entered each other's firing range. The humans attacked at range with lances and macro-cannons, while the Tyranids returned fire with bio-plasma and acid cannons.
The human fleet's numerical disadvantage quickly became apparent. The Tyranid fleet was not particularly adept at long-range firepower, but it still suppressed the human fleet in the engagement zone.
The converted transport ships moved forward, using their own hulls to shield the combat ships from damage.
A Tyranid cruiser that had crept up in stealth opened its massive maw and bit into a transport ship. Amid the teeth-grating snap of the ship's keel, a red flash erupted, blasting away half the fangs in the Tyranid cruiser's mouth.
Trading one transport ship to severely damage a Tyranid cruiser was worthwhile.
Such simple methods were the only way to give slow, weakly armed transport ships some combat capability through short-term modifications. They could either absorb damage for the capital ships or self-destruct to hurt the enemy.
Like the Astra Militarum, the Imperial Navy was a military force of