Nicole Jennings
Biology, Old Dominion University
BIOL 293: Cell Biology
Dr. Christina Steel
11/9/2025
Intestinal Crypt Cells in Snakes
How snakes can completely digest their prey, bones and all, has fascinated scientists and researchers for ages. However, trying to figure out exactly how they accomplish such a feat is no easy task. As there are many components, all working together, that give snakes this amazing ability. Snakes, however, find swallowing their food whole as a necessity, and being able to completely digest bone is an essential part of their way of life. As they need bones for their calcium and phosphorous intake (Starr).
However, surely digesting large amounts of calcium and phosphorous can lead to compromising effects and become detrimental to the snake. One must wonder how these snakes avoid taking in so much calcium and phosphorus without having any disastrous effects. One possible way is through what is being considered as a possible newly discovered cell type found in the snake’s intestines. A sort of enterocyte-like cell that has microvilli of various sizes, depending on whether the snake was fed or fasting, with folds that form crypts (Lignot, Pope, Secor). These crypts appear as tiny little pouches that hold ingested particles along the snake’s intestines. These crypts, however, look quite different based on their diet. Whether it be their normal diet, lack thereof, or even during fasting. In fact, these crypts can look different even when infused with extra calcium in comparison to their normal intake. For snakes fasting, these crypts were completely empty with tiny microvilli. This would make sense as there would be no calcium or phosphorous intake with no food. For snakes fed a boneless diet, the crypts appeared to be filled with small amounts of material, however it appears that this material was in fact very tiny amounts of calcium and phosphorus, or none at all, with rather low amounts of iron. With the iron itself showing on the scans. Snakes fed boneless prey enriched with calcium supplements, or extra calcium, showed almost all crypts completely filled to the brim with calcium and phosphorous. Snakes fed their normal diet, however, showed elongated microvilli in comparison and did in fact show larger particles in their crypts. Though not nearly as full.
Different particles in the crypts appear very differently in scans based on the snake’s diet. Fasting snakes showed no particles. This occurs due to the snake not digesting any material. Particles found in crypts of snakes that were fed boneless meals appear very dark, indicating that there are indeed particles, but that it is in fact iron and not calcium. Showing that food had been digested, but only small amounts of calcium and phosphorus had been ingested as well. Which is in contrast to what calcium shows up as under EDX analysis. Here, calcium shows up as a large, bright white particle or particles that in some cases completely fill the crypts. This is most especially seen in the calcium infused boneless meals given to snakes as they show up as a beacon of light under EDX. This occurs after the snake has ingested a meal with so much calcium that it cannot make use of it all. Snakes fed a typical normal diet showed crypts not nearly as bright, but showed crypts most definitely filled with particles or solid materials of calcium. This would also be more understanding as the normal diet not only consists of calcium but also phosphorous and iron in large amounts as well. The majority of particles found in these crypts are of phosphorous, iron, small amounts of oxygen, and calcium depending on the diet given to the snake. Snakes that were given diets rich with calcium will show as such. However, in snakes given boneless meals, these crypts will generally be filled with small amounts of all particles consisting of iron and oxygen, as well as small amounts of phosphorous and sulfur. They will also typically show little to no calcium at all however.
Regardless of whether their meals have little calcium or are absolutely enriched with it, snakes must still find a way to regulate it all. They do this through the use of calcitonin and parathyroid hormone, or PTH. Calcitonin is used to help regulate calcium in the blood by inhibiting the osteoclast’s ability to break down bone and releasing calcium. Slowing down the amount that is absorbed (Kaplan). Calcitonin also helps with the removal of extra calcium by helping with excreting it through the kidneys. PTH is both used in conjunction with calcitonin and against it. This actually helps them work together when it comes to regulating calcium levels in the blood. As PTH helps excrete phosphorous through the kidneys, allowing more calcium to be absorbed (Kaplan). This back-and-forth fight between PTH’s wanting to absorb calcium, and calcitonin wanting to prevent it, allows for the snake to regulate just the right amount of calcium necessary in the blood stream. This regulation of calcium levels in the blood, however, is affectively changed based on the diet of the snake. Snakes fed a normal diet or fasting seemed to have relatively close to the same levels of calcitonin and calcium. With fasting snakes having a slightly elevated level of both. With PTH, however, snakes that were fasted had much lower levels than fed snakes. Snakes fed a boneless no calcium meal seemed to have had a decrease over each meal in calcium. This would make sense as there was little to no calcium in the meals given, thus levels will drop. Their calcitonin levels seemed to be somewhat maintained though throughout their meals, which would also come naturally. As their meals lacked calcium, there would be little to no change in the calcitonin levels needed to inhibit absorption. The PTH levels in snakes fed low or no calcium meals seem to skyrocket as expected. While these snakes received little if any calcium, they were still absorbing phosphorus. These levels are expected as the snakes, regardless of calcium levels, still needed their phosphorus levels to be maintained and regulated so that they do not overdose on it.
It is a very interesting subject, the idea that a new cell has been found in snakes that could be the answer to how snakes are able to accomplish the undertaking of digesting a meal whole, bones and all. I think more experiments need to take place before a definitive answer can be found. The number of snakes used appears too small. Without more snakes being used in the experiment, it could be said that it was a coincidence that these few snakes just happened to have this specialized new cell. There really is no true control group. It could be said that other snakes of the same species may not actually have these cells and that the snakes used were anomalies. They also only used one species of snake. Without using other species of snakes, we cannot say for certain that all snakes digest bones using these specialized cells as we don’t know if all snakes have them. Or even if other species of snakes do, we don’t know if they are used in the same fashion. There is also the idea that this is a new cell type. By new, we don’t know if they mean newly discovered, or that snakes recently developed this new specialized cell and could have been digesting the bones of their meals in another way. I believe not only that other experiments should be carried out with other species of snakes, but also other animals. Animals such as the bearded vulture also digest bones. If it is found that they too have the same specialized cells, or cells specialized in much the same way but different, then this cell would not be considered new. Perhaps though this newly discovered cell is instead a primitive version of other crypt cells. In which case, I agree it would be a new discovery. Ultimately, I think the researchers did a good job making the case that this new crypt cell could be a new cell. Though I still think more research needs to be done. New experiments done. Perhaps even with different meals other than rats, such as birds. There are far too many flaws and not enough variables to show that this is the concluding factor in how snakes digest bones and control calcium intake. However, I do think they made great progress on the subject that otherwise had not been done before. I believe that it is a very interesting, though not fully researched area that they definitely did a great job with bringing the subject to light and pioneering the research to start further studies.
References
Starr, M. (2025, July 9). New cell discovered in pythons allows them to completely digest bones. ScienceAlert. https://www.sciencealert.com/new-cell-discovered-in-pythons-allows-them-to-completely-digest-bones
Lignot, J.-H., Pope, R. K., & Secor, S. M. (2025, July). Diet-dependent production of calcium- and phosphorus-rich ‘spheroids’ along the intestine of Burmese pythons: Identification of a new cell type? | journal of experimental biology | the company of Biologists. Journal of Experimental Biology. https://journals.biologists.com/jeb/article-abstract/228/14/jeb249620/368391/Diet-dependent-production-of-calcium-and?redirectedFrom=fulltext https://journals.biologists.com/jeb/article-abstract/228/14/jeb249620/368391/Diet-dependent-production-of-calcium-and?redirectedFrom=fulltext
Virata, J. (2025, July 10). Burmese python intestinal cells help Digest Bones. Reptiles Magazine. https://reptilesmagazine.com/burmese-python-intestinal-cells-help-digest-bones/?srsltid=AfmBOopO5HbTabQLBbrxmsLWkMkbzg1HjMCcEXXYYg5BOboTc4V4HdBp https://reptilesmagazine.com/burmese-python-intestinal-cells-help-digest-bones/?srsltid=AfmBOopO5HbTabQLBbrxmsLWkMkbzg1HjMCcEXXYYg5BOboTc4V4HdBp
Bassi, M. (2025, July 18). Researchers discover the trick that allows Burmese pythons to digest the bones of their prey. Smithsonian Magazine. https://www.smithsonianmag.com/smart-news/researchers-discover-the-trick-that-allows-burmese-pythons-to-digest-the-bones-of-their-prey-180987006/ https://www.smithsonianmag.com/smart-news/researchers-discover-the-trick-that-allows-burmese-pythons-to-digest-the-bones-of-their-prey-180987006/
Kaplan, M. (2014, January 1). Calcium metabolism and metabolic bone disease. Herpcare Collection. https://www.anapsid.org/mbd2.html
Lignot J., Pope R. K., & Secor S. M. (2025). Diet-dependent production of calcium- and phosphorus-rich ‘spheroids’ along the intestine of Burmese pythons: identification of a new cell type?. Journal of Experimental Biology, 228(14), Page. 10.1242/jeb.249620