Hello everyone,
I’m new here, so of course, I have a strange question. The bone I have to pick is namely, marrow. Is bone marrow found in all vertebrates? Since bone marrow in humans is a collection of stem cells (amoung other things), that perform a variety of taks, where is the bone marrow in a cetacean, snakes and eels found? The first group has prescious few long bones, and the second two don’t have any.
I’d hazard a guess that any animal that has a circulating blood system with oxygen in it needs RBC, and therefor marrow.
This link shows doctors removing marrow from rats, mice, dogs, and monkeys. Not the entire animal kingdom, but a fair representation
Just because it’s mainly the long bones in humans that make marrow doesn’t mean it’s limited to long bones in all critters with skeletons.
Ribs and vertebrae also contain marrow, just not as much by volume as, say, the average femur. Snakes have lots of ribs, so they may make up in quantity what they lack in quality marrow-bones.
The spleen and liver can also produce blood cells. That’s what provides red blood cells in the fetus before the long bones develop. In some species, these organs remain the main source of blood components.