Hello everyone and welcome back. Well for starters let me just say this will be my last post about the salamanders. I hope that you enjoyed and learned something from reading my blog these last few weeks. Hopefully, I inspired you to do more research on the salamander or even start your own blog on this species. But enough of that lets dive right into this week’s topic.

    This week I found a research article that focused on the limb bone stress and loco-motor forces during the movement of a Salamander. Specifically, the researchers focused on the femur of the Tiger Salamander. Before we go deeper into the article, I listed a few words below with the definition so it can be easier to read.

• Ground reaction force (GRF)- the force exerted by the ground on a body in contact with it.
• Locomotion- the movement or the ability to move from one place to another place.
• Femur- a bone of the thigh or the upper hind limb.
• Ectothermic- any cold-blooded animal or an animal that regulates its body temperature.
• MATLAB- a programming language and numerical analysis environment that include matrix calculations, and data visualizations.

    In this research, the authors had two hypotheses. One being that the salamanders exhibit low limb bone loads and high safety factors like ectothermic, non-avian replies and that torsion is a prominent loading regime in the salamander femur as in other species that use sprawling limb posture (K.M. Sheffield and R.W. Blob).

    The researchers used a total of five adult Tiger Salamanders, 3 females and 2 males, and persuaded each salamander to walk in place by gently squeezing its tail. With the help of modern technology, the researchers were able to slow down the footage of the footsteps and record the data from the plate. Several graphs were made to show the lateral and posterior view of the GRF. the mean for the femoral bending factor was also calculated the worst being at 4.5 and the best at 10.5.

    In summary, the findings using a tiger salamander confirmed the most broad patterns found in other tetrapod lineages. The safety factors were at about 10.5 in bending which is a little higher than other salamanders and suggests that salamander femora might help the variability in femoral stresses.

    This founding now helps support the broader hypotheses of limb bone stress in other tetrapods. I thought that this experiment was interesting for two reasons. First off, I have never seen anything like this before so I just thought it would be interesting to read. Secondly, I think that if I understand how something this simple (not really simple, actually very complicated) it would be easier for me to understand the different stresses and movements of the human body.

Well, guys, that’s it. We have officially come to the end of our Salamander journey. I hope you guys enjoyed my blog as much as I enjoyed writing it for you!!!

K. Megan Sheffield, Richard W. Blob

Journal of Experimental Biology 2011 214: 2603-2615; doi: 10.1242/jeb.048736

http://jeb.biologists.org/content/214/15/2603.short

Hello everyone and welcome back to another week of learning about Salamander.

Let’s just do a quick recap before we jump into this weeks discussion. In the last blog, we discussed one unique feature of the salamander. The one unique feature we discussed was salamanders being able to rearrange their cells at their wound sites so they can regrow their body parts.

But enough of that, lets dive into today’s discussion, the taxonomy of the salamander with the help of a phylogenetic tree.Why do we use phylogenetic trees you may ask? Well, we use a phylogenetic tree to demonstrate the evolutionary history of most organisms.

   In this phylogenetic tree, the author compared 36 species that fall into the Ambystoma genus. There are several sister groups, and 9 are outgroups. An example of a sister group is the Ambystoma textanum and the Ambystoma barbouri.  This phylogeny tree was constructed by comparing morphological characters. What is a morphological characteristic? It is basically the shape or size of an organism. The Ambystoma Annulatum, Ambystoma Cingulatum, Ambystoma Mabeei, Ambystoma Barbouri, and the Ambystoma Texanum were grouped here based on specific characteristics of its skull. In the group containing the Ambystoma Tigrinum, it is branched off based on its geographical location. One thing that unifies the members of this genus together is their ability to regenerate their limbs. 

 

   In the picture above, there are two different phylogenetic trees. While looking for a second phylogenetic tree to compare, I noticed that many of the articles stated that Ambystoma has a phylogenetic conflict. To solve or bring light to the situation a group of people came together and made the two trees pictured above. The first tree that is labeled “A” is separated by morphological characters like the very first tree we discussed. There were 32 morphological characters used to compare each Ambystoma. The characteristics included size, the shape of the skull, and spinal muscles. The numbers that are on the branches represent bootstrap values. A bootstrap value is when random sets of data combined with the re-run of phylogenetic analysis are reported as a percentage.

   There for the sister group between the Ambystoma texanum and Ambystoma barbouri are well supported at being labeled closely related. In the second phylogeny tree “B” were based on a different hypothesis of Ambystoma. The authors also used morphology to different group Ambystoma. This tree also included the allozyme and mitochondrial sequence-based estimates. There were a total of 26 allozyme characters and the numbers on this tree represented jackknife values. Even though the authors were trying to show the difference in the two trees both still came out very similar.

Well, that’s enough for this week. Be on the lookout for the next post about this unique animal!!!!

 

 

 

 

References:

1. https://www.semanticscholar.org/paper/Species-tree-reconstruction-of-a-poorly-resolved-of-Williams-Niedzwiecki/ff86a8cac792c3e9c672c0373794a91560da4c3c
2. http://tolweb.org/Ambystomatidae/15448
3. https://books.google.com/books?id=x-ZhDwAAQBAJ&pg=PA48&lpg=PA48&dq=Kraus,+1988;+Shaffer+et+al.,+1991&source=bl&ots=FgqQel4m_r&sig=ACfU3U31stDcvKbiqFujMlXqxH9n7qbVdA&hl=en&sa=X&ved=2ahUKEwir_YWOg7_hAhXvp1kKHYKsCboQ6AEwAXoECAkQAQ#v=onepage&q&f=false

 

 

 

 

 

 

 

 

Hello everyone and welcome back to a new week of learning something new about salamanders.

 

Have you ever got into a fight and hurt a part of your body and just wanted it to fall off? Don’t you wish you could just cut it off and it could grow back in a few days? Studies have shown that salamanders can regrow entire limbs and also regenerate certain parts of major organs. But how can they do this? Why can’t we as humans do this?

 

Well in salamanders it all has to deal with the rearranging of cells at the wound site. There are several phases that the missing part of the salamander goes through. When the limb is first lost the epidermal cells go towards the open flesh to cover it.
An epidermal cell is a cell in the basal layer of the epidermis, and it produces melanin. Over the course of a few days, the epidermal cells begin to thicken and form an apical epithelial cap. The epithelial cap covers the fibroblasts. Fibroblasts are a type of cell that produces collagen and other fibers. Once enough fibroblasts are created a blastema develops. Once the blastema is formed, blood vessels begin to regenerate onto it. Different genetic codes are found in the blastema as well to determine exactly what limb needs to be regrown. So what does all of this stuff mean?

In a nutshell, a salamanders immune system at a young age is a huge deal. If they don’t have macrophages, then they won’t be able to regrow their limbs.

 

 Check out this cool video of a salamander growing back its leg!!!

(https://youtu.be/qD1K7BoWVC8?t=57s)

 

 

 

References:

1. https://animals.howstuffworks.com/amphibians/salamander-regrow-body-parts1.htm
2.  https://www.sciencenews.org/article/how-salamanders-can-regrow-tails-lizards-cant
3.  https://www.rdmag.com/article/2018/09/new-insight-how-salamanders-regrow-limbs
4. https://www.ncbi.nlm.nih.gov/pubmed/23690624

 

Welcome Back Everyone!!!

This week we will discuss the anatomy of a salamander, but first, let’s just do a quick recap of these species. The salamander is a part of the Chordata phylum, and it is in the genus Ambystoma. There are several hundred types of salamanders, and their environments differ depending on the type. Salamanders have common anatomical features, but with living in different environments, they also have different characteristics. Now let’s get into the basic description of this fantastic species.

    Most salamanders have a slender tube shape with four short limbs, a tail, two eyes on the side of its head and small teeth. The respiratory organs vary for each salamander based on their environment. Some have lungs while others have gills. There are also some salamanders have gills and lungs. There is a wide variety of colors that salamanders come in. Usually, these species have dark backgrounds with yellow, or other bright color, markings. The markings on their backs can also range in size and shape. The markings that appear on the salamander helps them blend into their surroundings, so its easier for them to capture their prey.

 

 

 

 

 

 

 

 

 

 

    Since we know the basic features of the salamander let’s now focus on one specific type, the Tiger Salamander. The Tiger Salamander has a thick body with a long tail. The skin of this species is shiny and moist. It also has four short legs and can grow to about 33 centimeters in length. There are four toes on the front feet and five toes on the back feet. The tiger salamander is one type of the many salamanders that have lungs. In the image above, we see that a female has ovaries and the male has testes, but it is still hard to tell which one is which just by looking at it. Maybe you think that the colors on their backs would help, NOPE. One can only really tell during the breading season, and you must pay attention to the salamander’s tail. Near the tail, there is a vent near the reproductive organs, and it will swell, and once you look there, the genitals will be visible. Also, sometimes in the tiger salamander, the female is bigger while the males have a larger cloaca. Another cool thing about the salamander is that it can regenerate some of its body parts.

   There is one part of the Tiger Salamander that is used mainly for defense, the tail. A toxin is secreted all over the salamander’s body, but the tail is the most toxic part. When a predator eats the tail, death is expected, and the cool thing about that is that it can grow its tail back.

 

Before you leave, check out this cool short video of Tiger Salamander catching its prey. It also gives a few more details of its life.

(https://www.youtube.com/watch?v=MjAiWnzU2aE)

 

See you next time!!!!!!!!

 

 

References

1. https://www.britannica.com/animal/salamander
2. https://www.nationalgeographic.com/animals/amphibians/t/tiger-salamander/
3. http://fieldguide.mt.gov/speciesDetail.aspx?elcode=AAAAA01142
4. https://sciencing.com/salamander-characteristics-7873616.html
5. https://animals.howstuffworks.com/amphibians/salamander-regrow-body-parts.htm

What in the world is a Caudata? What does it do, what does it look like? These are just a few questions I asked myself when I first heard of Caudata. Before creating my blog, I did some research, so you can learn everything that you need to know. For starters the Caudata is one of the major orders in the amphibia class. The scientific name is Urodela and one common species in this order is the salamander.

 

At first glimpse the salamander resembles a lizard, but they do have major differences. For example, salamanders don’t have scales and have moist skin. Fun fact most salamanders secrete toxins all over their bodies. The Japanese Giant Salamander is the largest salamander and can grow up to about 6 feet.

 

Facts About Salamanders retrieved from:

https://www.livescience.com/52627-salamanders.html

 

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