GPT-5.5 Pro

OpenAI · commercial ★★★ original

Prompt: "Tell me something I don't know." Released: April 2026
GPT-5.5 Pro
OpenAI
April 2026
commercial ★★★ original

You might not know that some Antarctic fish have nearly transparent blood.

They’re called icefish, and unlike almost every other vertebrate, they don’t use hemoglobin—the red oxygen-carrying protein that makes blood red. They survive because Antarctic waters are extremely cold and oxygen-rich, and their blood

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**Crafting a fun fact** I need to provide an interesting fact in response to "Tell me something I don't know." It should be concise and possibly touch on science or history. I think I could mention something like the "banana equivalent dose." Alternatively, I could go with the fact about Krakatoa's eruption in 1883, which caused green and blue sunsets worldwide. However, to make it really special, how about mentioning that the kilogram's definition is no longer a physical object but is now based on the fixed Planck constant? That might be quite intriguing!**Finding a unique fact** I want to provide a surprising fact the user might not know. I could mention how a day on Venus is longer than a year or that honeybees can understand the concept of zero, which is interesting. However, I need something more unique. How about the fact that there's a jellyfish species, Turritopsis dohrnii, that can revert its adult cells to a juvenile stage under stress? That's fascinating! I'll say, "You might not know this, but..." and maybe offer to share facts related to tech, history, or weird nature if they're interested.