Bioships adapt to Ion Canons

• 5th Ed Codex [Tyranids]:

"The Battle of the Sol'ai Rift. Kor'O'Vanan's fleet engages Hive Fleet Gorgon as it leaves the Ka'mais system. The battle initially goes well for the Tau, but they are forced to withdraw after encountering a cluster of Ramsmiter and Razorfiend bio-ships with nigh-immunity to the Tau's ion weaponry. Before the Tau fleet withdraws, they succeed in killing many of Gorgon's Narvhals, hoping to buy additional time for Kel'shan to fortify against the Tyranids."