The Tentacled Invasion by Max Gunssler

The Fort Sumter is the fiercest pirate vessel in the galaxy.  The spaceship's crew is made up of 500 sultry space-babes, all wearing tight silver bodysuits. The beautiful vixens raid Federation vessels, rape the men, kill the women, and plunder their goods.  Horror strikes as a behemoth alien ship captures the Fort Sumter and invades it.  Now the space-babes must defend and survive against monster tentacles that seek to slice them up or impregnate them with alien spawn.