London Natural History Museum: Fish to Amphibians to Reptiles

2010/12/11
By Student Group

The 9th grade biology students recently traveled to London for a week-long field trip to many historical sites.  The students spent three hours exploring the Natural History Museum.  The following is the third in a series of posts written by the students to discuss what they learned.

by Dan, Eva, and Taylor
In London, we visited the Natural History Museum, it was full of specimens and models of various creatures around the world. Our group visited the Fish, Amphibians, and Reptiles exhibit. We saw many strange fish, with different features and abilities in the Fish section. We saw many kinds of exotic fish that each had their own way around things. Whether it be a long whip-like appendage or a sword-like nose, they were strange. Next, we saw the Amphibians, which were almost a mix between reptiles and fish. They are usually associated with water, have no claws, and have fin-like features. We saw some salamanders as big as 4 ½ feet long, and others as small as three inches, we even saw the biggest frog in the world, the Goliath Frog. When we came to the Reptile section we saw many alligators and lizards. We saw the largest lizard in the world, the Komodo Dragon, and enormous snakes like the Boa Constrictor. In the end, we had realized that they were like pieces of a puzzle. We considered that fish had evolved as the earliest life forms of the three, then came amphibians, and eventually reptiles. We came to the conclusion that fish (over time) evolved into amphibians, which then evolved into reptiles. There were visible similarities between each of the groups.
However, even before we were able to journey through the fish, amphibians, and reptile exhibit, we made our way through the Darwin Cocoon first. Upon our stop on the high floor in which the exhibit was found, we were given Nature Plus cards. As we went around the exhibit, we would simply slide the card under a scanner, therefore we wouldn’t have to absorb all the information at once and could reference back to it later. In most sections, there was a small video to watch and listen about what that particular section was about. Like any museum, there was also an information card that told you helpful facts about what you came to look at. At some of the special sections, there were tables that you could touch with your finger that would give even more information about the specific things that you wanted to learn about in the section. Many of the different sections were on specific organisms. We really enjoyed a enlarged replica of a mosquito. All those who are not entomologically or even biologically savvy finally get to see what a mosquito is and how it works. The mosquito exhibit was not just about malaria and various other diseases; it was about the anatomy of mosquitoes. Mosquitoes have two mouths or probosces, one shoot an anticoagulant (anti-blood-clotting chemical) and the other sucks in the blood. This was very clear on the large model displayed in the museum. In this particular section of the Darwin Cocoon, scientists study different types of bugs, decoding their DNA, preparing specimens, and getting a closer look at the different kinds of species.  My favorite part about the entire cocoon was the windows that you could peer into to observe how all the scientists at the museum worked. Unfortunately, there were no scientists at the moment who were working on anything, so we were unable to see them in action, but it was still enjoyable to see how they work and their environment. Overall, I would say that my group and I had a great time exploring the Darwin Cocoon.

The first exhibit we saw was fish, we saw strange, almost alien-like fish. As stated, they always have some strange way to help survive to reproduce. It was not about strength or size, but a trick the fish had up their sleeve to avoid the direct approach. For example, the Gulper Eel uses its large mouth to capture more prey. The anglerfish grows bio-luminescent algae in its lantern which it uses to lure in fish. Besides that, it has small parasitic males that attach themselves to the females and allow the female to reproduce whenever she needs to. Male anglerfish are roughly an eighth of the size of a female, have no “angler”, and rely on females for a food supply. Fish are aquatic animals with vertebrae (either bony or cartilaginous) and scales. Most fish are cold-blooded, meaning they rely on other sources of heat to maintain body temperature. The mudskipper fish uses its fins to walk on land and breaths through its thin skin. At first glance it almost appears to be a salamander with two legs. This can come across as a message to people that fish did evolve into amphibians. There is even a fish called the salamander fish (or commonly known as the lung-fish)! It has four fins (almost leg-like) that it uses to walk around on land with; it is a sign that fish evolved into amphibians. Unlike the mudskipper, which are about ½ feet long, the salamander fish can be almost a yard long! One can imagine all of the amphibians that evolved from this fish, chubby salamanders eating smaller amphibians. Fish vary in size and shape, but they all have a backbone and skull. Fish can be jawless, cartilaginous (meaning their bones are made of cartilage, or even armoured (although those are extinct). Fish, being around for a very long time have tons of variety. Fish have evolved into the strangest creatures; there are fish with huge fins attached to their skulls (rays) or fish with funnel-shaped rows of teeth in their mouth (lamprey). They aren’t small either; a whale shark can grow up to 41 feet long! Fish are among the oddest visible creatures on the Earth, and it is possible that more than half of the species of fish are undiscovered. Evolutionary footprints, like the mudskipper and the lung-fish and similarities in genetic structure have led scientists to believe that fish evolved into amphibians.

Like we stated before, amphibians are like a mix between fish and reptiles. Like reptiles and fish, amphibians are vertebrates. Their skin lacks and horns and scales and their appendages do not have claws. They typically lay eggs, which, unlike reptile eggs, do not have shells. They lay these eggs in small bodies of water or damp areas. They are very similar to fish in this way. Like fish, they are cold-blooded and rely on the sun or the water for body heat. There are three main groups of amphibians that make them up. However two of these groups, are currently known to be extinct. The remaining group contains frogs, toads, newts, salamanders and limbless creatures name Caecilians. Toads and Frogs, are a group of short-bodies, web-toed, amphibians that are characterized by a fish like juvenile stage and an adult stage characterized by leaping. Salamanders, are creatures known for their short noses, thin bodies and long tails. Their skin must remain moist and so they are usually found near bodies of water. Most juvenile salamanders may spend their childhood within water and rise above water when they have matured. Newts, are most aquatic salamanders that spend most all of their life within a body of water, and newts are capable of regenerating limbs, unlike most vertebrates. Caecilians are the rarest of all amphibians. They mostly live underground, therefore they are not seen as often as other amphibian groups. They are reported to look the most similar to earth worms and snakes. Caecilians completely lack limbs, therefore the babies resemble earthworms the most, and adults resemble snakes the most. The skin is smooth and traditionally dark colored, few have lighter colored skin. Their eyesight is there biggest weakness, given they spend so much time underground. Many, however, falsely accuse them of being blind, which they are not. They live in South America, south Asia, and parts of Africa. It has been proven that, Amphibians evolved from fish about 340 million years ago. However, they have some differences as well as similarities. Amphibians usually breathe through gills or spiracles when they are young and develop lungs as they grow, whereas fish rely on gills throughout their entire lives. Amphibians spend half their life on land and the other half in water. Reptiles and fish directly stay on land or in water. Also, as previously stated, amphibians grow lungs as they develop, and reptiles have lungs throughout their entire life. Amphibians were the first animals with backbone to colonize the land, and later grew even deeper into evolution with the creation of reptiles.
Over time, the reptile class evolved from amphibians. This is a process that takes millions of years, and during this time period, variations amongst the species occur. In other words, there are significant signs of hereditary differences. The biological goal of all living things is to survive and reproduce. The reason variations occur are because of this. The evolutionary process consists of having a common ancestor. Reptiles evolved from amphibians, (example: salamander to a lizard) and amphibians evolved from fish. A reptile’s differences between a fish and amphibians, is that reptiles have dry scaly skin, lay shelled eggs on land, and they live in dry warm areas. Reptiles have more similarities with amphibians, than fish, such as, the fact that they both rely on external sources of heat to control their body temperature. This goes back to the idea that reptiles descended from amphibians, because of their common characteristics.
Throughout time, fish, amphibians, and reptiles evolved off one another. It began with the fish which evolved into an amphibian, which evolved into a reptile. Each share a common ancestor, yet still have hereditary differences, thus the concept of evolution. Although they do have similarities and differences their common ancestry is the origin of each species. This explains the concept of organisms changing over time.
(Note: This group submitted no questions for their readers.  Develop your own questions and answer them.)

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  • Anonymous

    Great post, Eva, Taylor and Dan! It was so interesting to learn about the evolutionary process that occurred over time! I never thought that reptiles descended from fish! Both types of animals are very different today, which is where I wondered: how long did the entire evolutionary process take and how exactly did the two organisms evolve? And, what are the specific differences and similarities between the two organisms? I did some additional research to answer my two questions. Firstly, as all three of you mentioned amphibians evolved from fish 340 million years ago, but the process from fish to reptiles occurred over millions of years. Apparently, fish that lived in schools and groups started to venture out onto land staying close to pools and bodies of water to hydrate and feed. The fish ventured out to land in the first place because their food source might have been low and there were more food opportunities on land. Eventually over time, fish bodies’ grew more and more adapted to land and were not as reliant on water for breathing. They eventually laid their eggs on land and the eggs developed a calcified shell that did not rely on water to hydrate the newly formed organism: the amphibian. Two examples of early amphibians are Acanthostega and Ichthyostega. Next, the amphibians traveled further inwards no longer depending on water for breathing and eating. The amphibians grew apart and adapted to different environments, therefore, creating different species and characteristics (or variations) within the original form of the amphibian. These new species are now classified as reptiles.

    Sources:
    http://www.all-about-reptiles.com/evolution.html
    http://hubpages.com/hub/The_Evolution_of_Reptiles

    A question for other commenters:
    What are the specific differences and similarities between the two organisms?

  • Anonymous

    I loved this post, guys ! I was not fortunate enough to see this exhibit, but your details really filled me in. You were really informative; and like Molly, I was unaware of the strong relation between fish, amphibians and reptiles! After reading Molly’s comment about the time span of this evolutionary process, I decided to answer her question and compare /contrast fish, amphibians, and reptiles. I also included two really cool videos below. Also, the hyperlinking didn’t work, so I had to re-copy all the links I used, that’s why it’ll be annoying to read :(
    The estimated [http://bit.ly/h2CmDD] 20,000-40,000 fish [http://bit.ly/fluCjs] (a taxon http://bit.ly/fnBfbc ) in the world are aquatic vertebrae, and like amphibians, are mostly ectothermic [http://bit.ly/hjUJaS] have three-chambered hearts and are limbless. The common misconception about fish is that all fish have fins (eels don’t) and scales (catfish don’t), and only live in water. However, lungfish [http://bit.ly/e6EdUJ] can survive outside of water and are known for having the ability to breathe gaseous air for months; African (Protopterus) and South American (Lepidosiren) lungfish estivate [http://bit.ly/fee7u3] during droughts in mud, and Australian (Neoceratodus,) lungfish breathe air if the water turns stagnant [http://bit.ly/h2bRKz]. In addition, I found that the term ‘fish’ itself does not specifically classify a certain class of organisms, but applies to more than one (taxon). Amphibians [http://bit.ly/g2Apob] (6,763, [http://bit.ly/gSQqdD] of the class Amphibia http://bit.ly/eEQ132) are organisms that live ‘double lives,’ they live part of their lives in water and partly on land. Some amphibians include newts, salamanders, toads, and frogs. The main ways you can characterize an amphibian is that it is a tetrapod [http://bit.ly/figVTH], a vertebrate [http://bit.ly/dM0kre ] ectothermic, has a three-chambered heart, and either breathes with gills, lungs (force air through lungs with mouth muscles) or through its skin. Amphibians have thin, moist skin and some can contain poisonous glands (called parotoid glands [http://bit.ly/hIig27]) used for protection. Lastly, reptiles (7900 species, of the class Reptilia [http://bit.ly/g3kPZ6] ) all have scales, are ectothermic, tetrapods, and lay hard-shelled eggs. Examples of reptiles are snakes, lizards, alligators, crocodiles, tortoises, and turtles.They breathe air, sucking it in with their thoracic cavity and have no muscular diaphragm. Reptiles have tough/dry skin [http://bit.ly/hlSBh2]to protect themselves from injury. They also have a more efficient body support than amphibians, their limbs are specifically for land and reptiles generally walk with their body close to the ground and with their legs outward. Reptiles are known to modify their activity [http://bit.ly/glLzwJ]and change location in order to adapt with a comfortable environment because they cannot control their body temperature.

    Here are two videos: One is a clip [http://bit.ly/fdI8SY] from the 1979 special “Life on Earth: A Natural History by David Attenborough” about how fish could possibly reach land. The second video [http://bit.ly/eTJV2l] is a BBC video about the lungfish and other animals that find ways to survive in fatal environments.

    Other Links (not hyperlinked):
    Reptile/Amphibian Misunderstandings: http://www.anapsid.org/myths.html
    Reptile/Amphibian Characteristics PPT: http://bit.ly/hlSBh2

    Question: What are fish/reptiles/amphibians other than the lungfish have evolved to adapt to their harsh environment like it has? How/why did they evolve, and how long did it take? Can you explain how organisms are classified, and what I meant by the term ‘class?’ :D

  • Deirdre

    Hey Molly! What an interesting response to this article! I loved your take in this post so I decided to research your question: “What are the specific differences and similarities between the two organisms?” I researched and found that their are many similarities. Some include that they are both cold blooded, both are found on every continent besides Antarctica, and both reproduce creating eggs. There are differences in the construction of the organisms eggs. Reptiles produce leathery shells designed to protect the organism inside. Amphibians lay soft eggs with a thin membrane and usually attach them to the stems of aquatic plants. When a Reptile hatches, it comes out in the form of a mini adult, but in the case of an Amphibian, these animals emerge in different forms and go through metamorphosis until they become full grown adults.

    http://www.wisegeek.com/what-is-the-difference-between-a-reptile-and-an-amphibian.htm

    Can anyone find any more differences?

  • Anonymous

    Wow guys, this was such an interesting post! After reading this post, I was shocked to find out how closely related fish, amphibians, and reptiles were. I decided to research more about caecilians, as you had mentioned that they were the rarest type of amphibian. Caecilians are legless, armless, and slimy worm-like creatures that have ringed or folded skin. These folds are called annuli, and caecilians are often brown, gray, black, yellow, or orange in color. In order to reproduce, some female caecilians often lay eggs in damp holes near water, and when the young hatch, they use a fin-like structure to help them get to the water. There, they feed on plankton, and develop into adult caecilians. Their gills are replaced by a single, lung, they grow annuli, they develop sensory tentacles, and their skin becomes thicker. After this process, the fully grown adult caecilian will move back to land, where they will burrow into the ground. Some female caecilians, however, give birth to fully grown offspring. Most caecilians live underground, and have little need to see or hear. Therefore, they have extremely tiny eyes and no ear openings. They have extremely sharp teeth which they use to catch prey, such as frogs, small snakes, or mollusks. This was such a riveting post, and I am sorry that I didn’t get to visit this exhibit.

    http://www.sandiegozoo.org/animalbytes/t-caecilian.html

  • Anonymous

    Great comments, Molly and Deirdre and great post, Eva, Taylor, and Dan! Molly, I specifically like your question about the differences and similarities between amphibians, reptiles, and like Deirdre, I decided to do some additional research on the differences. All three are cold-blooded vertebrates. One distinction is their need for water. Amphibians have permeable skin and need moisture or water to prevent pollutants from getting inside. Most Reptiles can live away from water and don’t absolutely need it to survive. However, fish absolutely need water to survive and they can live in either salt or fresh water. Another dissimilarity is their skin. Fish are commonly covered in slimy scales. Reptiles usually have thick, shields or plates that prevent moisture loss on dry lands. Amphibians generally have moist, glandular skin.

    Sources:
    http://animals.about.com/od/reptiles/p/reptiles.htm
    http://animals.about.com/od/amphibians/p/amphibians.htm
    http://animals.nationalgeographic.com/animals/fish/

    However, Amphibians, Reptiles, and Fish also have many similarities. What are some of those similarities?

  • http://extremebiology.net/blog Ms Baker

    Good question. Also, to what effect are mammals such as humans related to these groups?

  • http://extremebiology.net/blog Ms Baker

    Great job Cartland. I really liked how you related this topic to what you know about natural selection.

    What about amphibians make them so vulnerable to pesticides and habitat loss? Why can’t they just adapt and evolve?

  • http://extremebiology.net/blog Ms Baker

    Nick, it would be great if you could include the major differences between a worm and a caecilian in your comment, rather just including the link.

  • http://extremebiology.net/blog Ms Baker

    Thanks Molly! :-) Great information. I guess I wasn’t clear, though. I’m looking for similarities humans have with fish, amphibians, and reptiles. For example, there was a really great popular science book that came out a few years ago called, “Your Inner Fish.” Can anyone find out some of the facts from that book to share here?

  • Gurk_14

    Great job guys! While we were given some time to go around I went through that exhibit. I didn’t have enough of time but it was great visiting it. After this magnificent post, with your help I learned a lot. After you guys mentioned a salamander evolved from a reptile to amphibian, I wanted to do so research on them even though there very popular. What I tried to do was find some rare facts about salamanders. One fact is the name salamander means “fire lover”. One question I wanted to answer about salamander is how do they breathe? Well I did some research and learned that salamanders breathe through their gills, lungs, mouth lining, and skin. Water salamander lack lungs so they breathe through their skins and mouths. A salamander can live about twenty or thirty years. Salamander’s skin is very sensitive to the air, so if the air is clean then the salamander knows that it’s in a clean habitat. Salamanders spend almost their entire lives hidden under rocks or logs. They can grow about nine inches. An important fact that is not known much when we compare humans to salamanders is that salamanders have ten times more DNA in each cell than humans do.
    http://www.shadescreek.org/Salamander%20Facts.html
    http://animals.nationalgeographic.com/animals/amphibians/spotted-salamander/

  • Anonymous

    Great post Eva, Dan, and Taylor! I never knew that fish, amphibians, and reptiles had such a connection to one another. This was such a fascinating topic. After reading this post and some of the previous comments, I did a little more research on the relationship between humans with fish, amphibians, and reptiles. I looked into the book titled “Your Inner Fish,” which Ms. Baker mentioned above. This book was written by Neil Shubin, a human anatomy teacher. Shubin explains in the book that the bodies of creatures like fish, amphibians, and reptiles are “often simpler versions of our own [human bodies].” As an anatomy teacher, Shubin uses the bodies of other animals to help his students to understand the human body. In his book, Shubin said that the easiest way to teach his students about the nerves in the human head is to show them the head of a shark. Similarly, the easiest way to teach his students about human limbs is to show them a fish. The easiest “roadmap” to the human brain lies within reptiles. As you can see from Shubin, humans have a strong connection with fish, amphibians, and reptiles.

    Sources:

    http://books.google.com/ebooks?id=c008kdNwR1cC&dq=your+inner+fish&as_brr=5&printsec=frontcover&output=reader&source=gbs_atb

  • GUNNAR_SIA

    Wow Emily, great comment. i knew that reptiles, amphibians, and fish were related, but like Emily, did not know that they were really close. I did some research and image look ups on the rare caecilians because i did not know what they looked like even though you described them, i had to take a look myself. They are like Emily said slimy and worm like creatures, you can take a look yourself from the links below to see what they look like and how they live!

    http://paleocave.sciencesortof.com/2010/08/10-animals-you-probably-didnt-know-about/

  • Anonymous

    Nice post guys. After coming back from london i now wish that i could have gone to this exhibit, but with your post i felt that i have been their. I decided to answer, what about amphibians make them so vulnerable to pesticides and habitat loss. I did some research and found a book called Living in the Environment: Principles, Connections, and Solutions By G. Tyler Miller, Scott Spoolman. In this book he talks about how frogs have traits that make them vulnerable certain points in their life.
    As adults frogs live on land and eat insects, which can make them vulnerable to pesticides, also the eggs can be affected by uv radiation because they don’t have protective shells. When frogs and reptiles use sunlight to warm their bodies they are also exposing them to uv radiation. Their is no one single cause that contributes to amphibians dying out. Habitat loss Prolonged drought, Pollution including pesticides, increases in uv radiation and parasites are some factors that contribute to amphibians dying out. check out this link to find some more interesting information

    Link:
    http://books.google.com/books?id=5gC9Dy1YWfkC&pg=PA94&lpg=PA94&dq=What+about+amphibians+make+them+so+vulnerable+to+pesticides+and+habitat+loss%3F&source=bl&ots=FE9JWk7Gll&sig=VCT9ET4-l1rcwVfiykhYeNtoiTk&hl=en&ei=-skGTaHAGIS0lQfx7fSzCQ&sa=X&oi=book_result&ct=result&resnum=1&sqi=2&ved=0CBcQ6AEwAA#v=onepage&q=What%20about%20amphibians%20make%20them%20so%20vulnerable%20to%20pesticides%20and%20habitat%20loss%3F&f=false

  • http://extremebiology.net/blog Ms Baker

    Great! But, where are your sources?

  • Anonymous

    Oh, I apologize for not having them posted before !
    Here they are :
    http://urbanext.illinois.edu/worms/facts/index.html
    http://www.naturehaven.com/Frog/caecilian.html

  • http://extremebiology.net/blog Ms Baker

    Accept

  • http://extremebiology.net/blog Ms Baker

    Source?

  • http://extremebiology.net/blog Ms Baker

    Source? Give us some links to information or videos of these sharks! You need to contribute some new sources to get credit.

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