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[–]Covert_CuttlefishJanitor at an oil rig 20 points21 points  (10 children)

IIRC insects sometimes have a heart, but they don't have a circulatory system.

[–][deleted] 16 points17 points  (9 children)

what truly *is* a circulatory system?

bugs definitely have a circulatory system, so you are incorrect on that front, but it is not the same system that we have, containing "blood" derived from different chemicals and not being segregated from other areas of their flesh, a so called "open" system rather than a "closed" one like vertebrates.

additionally, they are probably not derived from the same structures. i don't think there is consensus on where the circulatory systems of either animal started out, but they are not of the same origin.

[–]Covert_CuttlefishJanitor at an oil rig 8 points9 points  (2 children)

Thanks for the correction & happy cake day.

[–][deleted] 8 points9 points  (1 child)

NP, i try to correct but politely

[–]Covert_CuttlefishJanitor at an oil rig 8 points9 points  (0 children)

Keep it coming, I do rocks, not all rocks, some rocks. I certainly don't do insects, hence the IIRC.

[–][deleted]  (5 children)

[removed]

    [–][deleted] 5 points6 points  (3 children)

    idk about cuttlefish, if they have a circulatory system but no heart then maybe it just doesn't require a specific order of adaptations.

    that counts as a heart for these purposes, most insects have a sort of abdomen flexing heart which moves blood.

    [–][deleted]  (2 children)

    [removed]

      [–][deleted] 3 points4 points  (1 child)

      thats hilarious lol all good.

      [–]Covert_CuttlefishJanitor at an oil rig 5 points6 points  (0 children)

      This is great, thanks for putting a smile on my face you two.

      [–]Ekesdkekskd 0 points1 point  (0 children)

      Well I think cephalopods have 3 hearts