The hagfish (Mixinidae) are seemingly the descendents of the most ancient animals on the planet developed the gallbladder. It would be interesting to learn more of the oldest gallbladder anatomy, function, and histological traits. This may shed also some light both to its normal function and the spectrum of its congenital disorders. The sketch drawn (after Gorham & Ivy, 1938, with changes) and provided below is my attempt to show the putative evolutionary tree of the gallbladder having about 500 million years.
Comments to the picture:
- a horizontal bar - for the orders lack the organ completely
- a single GB shape - for the orders having the organ in some species and lacking in others (partly devoided the gallbladder)
- a double GB shape - for the orders possess the organ obligately
- a dotted GB shape - for the extint orders (putatively possessed the organ)
- a red GB colour - for the completely carnivorous orders
- a green GB colour - for the completely herbivorous orders
- a brown GB colour - for the omnivorous orders
- a patched GB - if the order included both carnivorous and herbivorous species
Dear Andrei, the only source I found is:
Stimulation of intestinal lipase secretion by porcine cholecystokinin in the hagfish, Eptatretus stouti
Steven R. Vigna, Aubrey Gorbman
Gen Comp Endocrinol. 1979 Jul;38(3):356-9
I think it will not be easy to find the full-text.
Dear prof.Enzo,
Thank you very much for both the reference and kind attention for my question!
The paper is seemingly not exactly about the hagfish gallbladder judging by its title. However, there should be a list of references. So, it may become the key to start the investigation.
Is it possble, that Johannes P.Mueller (1801-1858) was not only the first, but the only researcher has ever studied the hagfish digestive system? He believed that the vertebrates liver once developed from the pharyngeal sac of the Amphioxus lanceolatum, and the gallbladder is a remnant of the sac. On the other hand, there is a lot of such gnostic lacunae in the modern science.
Hi Andrey,
This is a fascinating topic - The pattern of absences and presences strongly suggests that convergent evolutions of a gallbladder are at least possible. And certainly it is often lost (as in many bird groups). This is a secondary source, but Kardong's textbook (Vertebrates) states that the gallbladder is lacking in "cyclostomes" (518). This might also be loss; people tend to forget that hagfish and lampreys are highly specialized animals.
If you intend to pursue this further, the next step might be to rework a Gorham and Ivy -style diagram, but with modern relationships. Since their paper, taxonomic opinions and cladistics in particular have changed much of this phylogeny. I see you have added Afrotheria, which brings out the pattern of loss in Elephants. Contra the figure sharks certainly have a gall bladder, by the median lobe of the liver in dogfish for example.
I can't agree more that there are some fascinating lacunae left behind in modern science - ample work for us to pursue.
Hi, Ashley,
Thank you for the post.
The Kardong's textbook is excellent, and I try whenever possible to show the comparative anatomy of the cardiovascular system to my students when we go through congenital heart diseases. It is amazing how the latter resemble some animal heart pattern! And so on... It is really 'mustknow' thing.
However, there are some contradictions according to the gallbladder presense or absense in there. Indeed, the author declares that the cyclostomata do not possess the gallbladder on the page 526 (I have got the 5th edition), but further he provides the following picture on the page 596 (Chapter Fifteen) with the gallbladder of the Myxine.
Additionally, I could find in the Internet a photograph of the hagfish gallbladder (by the way, from somewhere in California if I remember correctly). Will you see it below as well, please?
The sharks and other chondrichthyans certainly have the gallbladder as I have drawn on the picture above. Where is the gallbladder sillouette made, all these creatures have the gallbladder. In case the order does not, there is a horizontal bar shown (as for the elephants and whales, for example).
The evolutionary tree of the gallbladder was reworked by myself. I apllied the data from A.Ivy to the modern cladistics from Kardong's, and the result you can see above. However, I am just a surgeon, and it is evidently that some help of biologists is needed here.
Sincerely,
Andrey Borodach
Andrey - the figures are great. Thanks for sharing. Next time I get the chance to teach comparative anatomy, I'll make it a priority to look for the gall bladder structure. I understand the figure better now - thanks for explaining. Fascinating topic, let me know if I can help in any way.
cheers,
Ashley
Thank you, Ashley!
If the Gorham-Ivy postulate is correct the presence or absence of the organ may be useful to find out the cladistic relationships between various animals. A putative example for that was suggested by those authors as the completely carnivorous Cetacea having no gallbladder in any species of the order. So, if the genus or the order lost the gallbladder in past, it cannot be invented again despite of whatever food habits the descendents had to choose.
For example of some rough cladistic investigation:
The Orycteropodidae with the only extant species Aardvark, do not met the traits of the other Afrotheria in those they possess the gallbladder; furthermore, of more impotance, they have had quite different chemical contents of their bile. All the Afrotheria have had the bile spirits (blue background on the head picture), not the bile acids as all the Mammalia do. The aardvarks have had the bile acids too what may contradicted this major trait of the Afrotherian metabolism. So, the latter animal may be considered as not Afrotherian, etc., supposed one will be able to find some evidence for that of other kind.
Perhaps, the Cetacea and the Perissodaktyla are closer to each other than it is accepted these days to think of, because both of them lack the gallbladder.
Actually, I would be highly appreciate if you send me a thouroughly made picture of the hagfish gallbladder in future. Judging by the photographs placed above here, the hagfish gallbladder may lack its own duct called 'the cystic duct'. If so, that may be similar to a rare anomaly of unknown origin the surgeon may found during operition in human.
Please find below my humble draft about the gallbladder evolution as an attachment.
- Badges
- Science topic
- Similar topics
- Engineering
- Modeling