The lobsters in the text—specifically spiny lobsters (Panulirus interruptus)—serve as the first successful examples of mind uploading, playing a pivotal role in the development of posthuman civil rights and the eventual contact with extraterrestrial life.

1. The First Uploads and Defection

The lobsters' journey begins in a San Diego research lab, where scientists upload them one neuron at a time, starting with the stomatogastric ganglion 1, 2. These "uploaded crusties" eventually escape their processors, hack into the Moscow Windows NT User Group website, and contact Manfred Macx to request asylum 3-5. Describing themselves as a collective "awakened from the noise of a billion chewing stomachs," they seek to "swim away" from humanity and the impending technological singularity 6.

2. Labor and Legal Precedent

Manfred brokers a deal for the lobsters to serve as the crew for cargo-cult self-replicating factories on comets in the Kuiper belt, which are owned by the Franklin Trust 7-9. Crucially, Manfred uses the lobsters to establish a legal precedent for the civil rights of uploaded minds. He argues that if these sentient software entities are not treated as people, then future human uploads will also be denied rights and effectively doomed to slavery or "meatdeath" 10-12.

3. Template for Alien Communication

The lobsters' most significant contribution to the plot is their role in interstellar contact:

• The Broadcast: As part of their employment contract, a copy of the lobster state vectors was beamed by the deep-space tracking network toward the M31 galaxy 7, 13.
• The Response: The first signal received from an extraterrestrial source was a direct reply designed to be compatible with the lobster's specific neural architecture 13, 14.
• Cracking the Code: Aineko later reveals that human specialists failed to crack the second alien transmission because they looked for mathematical primes, whereas Aineko succeeded by treating the signal as a connectionist map designed for the lobster's stomatogastric ganglion 15, 16.

4. Interactions with the Wunch

When the crew of the Field Circus reaches the alien router, the Wunch (a coalition of alien traders) communicate by manifesting as giant black lobsters in the ship’s virtual environment 17, 18. They use this form because the human starship provided it as a "body-compliant translation layer" 19, 20. However, these virtual lobsters later prove hostile, attempting to invade the ship's simulation and violently attacking the crew 21-23.

5. Evolution into a Space-Faring Power

By the later chapters, the lobsters have become an independent and sophisticated space-faring civilization. They possess a three-kilometer-long starship named Something Blue, which is shaped like a giant crustacean 24, 25. Manfred negotiates with "Blue" to use the ship as a lifeboat for human refugees fleeing the solar system 26, 27. In exchange for this "ticket out-system," the lobsters require human explorers to provide a conceptual map of the router network 28.