Final answer:
The false statement about squid is that their systemic heart receives largely deoxygenated blood. It actually receives largely oxygenated blood from the gills. The other statements about the squid's circulatory system are true.
Step-by-step explanation:
The statement about squid that is false is 'Their systemic heart receives largely deoxygenated blood.' In squid, the systemic heart receives largely oxygenated blood from the gills, not deoxygenated. Squid have a complex circulatory system with three hearts, two of which are branchial hearts that pump blood to the gills where it is oxygenated. The oxygenated blood then enters the systemic heart, which pumps it to the rest of the body.
The other statements are true. The systemic heart is indeed myogenic, meaning it initiates its own contractions without needing signals from the brain or nerves. And, as mentioned, blood does enter the systemic heart from the gills, and it is the branchial hearts that pump blood through the gills.
Learn more about Squid Circulation