Wednesday, April 29, 2015

Natural History: Ground Skink

Species: Ground Skink
Scientific name: Scincella lateralis


The smallest skink in the Scincidae family, the ground skink measures roughly 3 to 5 inches. This species has a smooth tan body with a dark stripe down the length of its side (dorsolateral). Fun fact: The ground skink has a transparent disk in the lower eyelid that allows the skink to see when its eye is closed! A new take on sleeping with your eyes open. This small skink scampers over the leaf litter on the floor of the woods. A very skittish creature that takes refuge in the nearest hiding place. As we walked through the trail at Dixie Plantation, a small movement caught my eye. I immediately stopped walking and glanced down. There on the leaves was a ground skink! In a flash, I reach down and scooped it up. I was unable to determine the sex of the individual I caught, but from the size I inferred that it was an adult. The ground skink can be found in along the eastern coast and throughout the southern states. 
I was extremely lucky in catching the ground skink as they are fast creatures that do not hesitate to run to shallow water to escape predation. With their small size, they can easily disappear from view. It was a great field trip! Not only did I catch a ground skink, but we saw a hognose and a timber rattlesnake! It was a very exciting time! With each trip after, I seem to attract the ground skink and have since caught several others on different trips! The ground skink is a pretty cool species and one that is easily recognizable from other lizards.


Class Mascot- Loggerhead Sea Turtle


I think that our class mascot should be the Loggerhead Sea Turtle, or Caretta caretta. On our field trip to the South Carolina Aquarium we saw several loggerheads in the Sea Turtle Hospital. These turtles were recovering from bacterial infections, motor boat accidents, and exposure to cold temperatures. The loggerhead is a great species to represent our herpetology class for several reasons. The loggerhead is the state reptile of South Carolina and nests primarily in the southeast of the US. Out of the 40-200 eggs each female lays, it is said that only 1 out of every 1,000 hatchlings make it to adulthood. Right from birth these turtles are faced with a tough road. Loggerheads also play an important part in the marine ecosystem. They carry colonies of small animals and plants on their backs providing important habitats to other organisms! 
As a city with beaches where loggerheads nest, having this turtle as our mascot would help bring attention to the conservations efforts being made, and that should be continued to be made, in Charleston. Campaigns for turtle excluder devices in shrimp nets and lights out on the beaches are great steps towards saving this wonderful species. Not only are loggerheads an important subject for conservation, they are also extremely cute. Sea turtles are amazing creatures traveling great distances and living long lives and having them as our class mascot would be great for their species. As my favorite animal, I believe that they deserve to be the face of our class!
Our Class Mascot: The Cottonmouth Snake (Agkistrodon piscivorus)



     After being able to enjoy and learn at the various sites throughout the semester, I still feel connected to the first field trip to Caw Caw County Park. It was the first time I've ever gotten a chance to really look at herps in the field, and I must say it was a wonderful experience. The first field trip is very near and dear to me, and I could never forget the moment when I laid eyes on the beautiful cottonmouth. The whole class was amazed, as we were impatient from the beginning to catch at least a glimpse of a cool snake. This by far exceeded our expectations and was one the most memorable moments the class experienced. Because of this, I feel the cottonmouth should be our class mascot. 
     The cottonmouth is notable for its deadly venom and forceful bite, and is one that shouldn't be messed with. It's very unique and can easily be recognized due to its facial pits, broad head, elliptical eyes, and front fangs. These qualities in this snake makes it all the more beautiful and mesmerizing, however it should be considered as our mascot because even these snakes are looked down upon by some. These snakes are dangerous, however their danger is overly exaggerated making people fearful of them, which may also lead them to kill or harm the snakes. This is very detrimental to the species and also the environment. People should be aware of these snakes, however they should also be encouraged to not harm them in anyway as this could be detrimental to their population as conservation is quite difficult and species loss is on the rise. 
     The cottonmouth should be considered for our class mascot. Not only is this animal beautiful, it is quite unique and has some amazing qualities that makes it one of the most amazing species I've ever encountered. I was truly amazed, and I hope that with this as our mascot, others will appreciate it just as much as our class did. 

Class Mascot?

I had a lot of fun reading other people had to recommend for our class mascot, and when I have to nominate one, I'm finding myself in a hard situation. I think that hognose snake our Thursday group encountered was super cool and put on a great show for us. But the little ground skink was super dossal and nice to me too! And so were the greater siren, and pretty much every other herpts we've encountered! I've also started to appreciate many of the frogs when I studied for my lab final.

It is a tough decision, and we ARE covering two very different classes in herpetology, so picking any one animal won't really do the other ones, or the other class, justice. And I also agree that we should pick something colorful and attention grabbing. So, maybe we should just let this dragonfly that liked to hang out with us on our last field trip be our mascot?


Just kidding.

Well, if I have to pick one for our CLASS, I'd choose the two-toed amphium, Amphiuma means, since it greated us in huge numbers (8) on the very first field trip, and greeted us with its appearances frequently through the following field trips, including that one that died on the very last trip (sad). They are also very unique in its number of toes, and its smooth defense mechanism. And it's also a peaceful little things that serves the ecosystem well since many water birds like to feed on them. Plus, I'm sure we are all very thankful for the amount of trouble it gave us memorizing its Latin name LOL.        

Class Mascot: Alligator mississippiensis

Our class mascot should be the American alligator or Alligator mississippiensis. Compared to all of the reptiles and amphibians our class has come across on our field trips, nothing was more amazing than seeing these creatures in their natural habitat. Although the salamanders, lizards, frogs, snakes, and turtles were fascinating, nothing compared to the incredible size and beauty of the American alligator. Although our class only came across the alligators on one field trip to Donnelly State Park, when we discovered these creatures at the first site, everyone was amazed. First, the smaller alligators were seen on one side. They got startled and all jumped in the water which in return startled me! As we proceeded to look on the other side of the bridge, three juvenile alligators were spotted. We knew the mother must be close by, and sure enough she was tucked away watching closely in the water. She will continue to watch her young for about two years providing them protecting from predators until they are large enough to fend for themselves. The juvenile alligators were about six inches long and had a beautiful orange striped pattern along their dorsum. After this site we preceded to the last site where a huge alligator was spotted along with many others. All were basking along the side of the water. The first one we saw was breath taking. The scutes along its back were very raised and the alligator was about eleven feet long. Some alligators can reach up to 14 feet and 400-1000 pounds. The adult males are larger than the females. These creatures prefer to live in freshwater habitats where they spend time in the water swimming as well as outside the water basking.


If alligators were our class mascot, it could be our duty to help preserve the species that was once considered endangered. Their large size often scares humans and leads to them being considered a threat. Relocating alligators does not work because of their extreme territoriality. Eventually the alligators can find their way back to their original habitat and this leads to the alligator being caught and killed. If you noticed at Donnelly State Park there were signs reading “A fed alligator equals a dead alligator”. Meaning, people feed the alligators, which leads them to come to trust humans. The alligators will then get extremely close to humans that are in the area in hopes of getting more food. This often scares humans since these creatures are so large and powerful. Humans report the alligators as a dangerous threat and the alligator is then shot and eliminated to prevent them from harming humans. Educating humans about these alligators is extremely important in the conservation of the species.

A Peek into a Huge Turtle Mouth!

I'm posting a very cool video I took at the optional field trip at the Turtle Survival Alliance, featuring us interacting with this awesome Asian brown Tortoises, Manouria emys.(You know it's awesome because it's Asian~)

This particular individual is a female and is estimated to be over 30 years old. It has a hole drilled at the edge of its carapace from when she was captured by the locals to sell to the turtle market. What they do is they put a rope through the hole and tie her up so she can't escape. She is also blind due to cataracts--she thought we were feeding her with food, that's why she kept opening her mouth. She was very friendly (maybe).

I won't say too much, you can find more information from Leah's blog: http://ourherpclass.blogspot.com/2015/04/trip-to-tsa.html , which inspired me to have this post.

(PS: I am super glad that this website saves my work automatically! There was just a power problem where I was and hooray not having to type up everything again!!!)

Class Mascot: Coluber Constrictor


I think that our class mascot should be a snake, specifically the black racer or Coluber constrictor. Snakes are amazing animals, and are greatly misunderstood because not all snakes are dangerous and harmful, as most people wrongly assume! Before taking herpetology I was one of these people who negatively stereotyped snakes, however after studying them and having first hand experiences with them in the field I learned to appreciate them. Thus why I think a snake is the perfect class mascot. It came down to choosing between the cottonmouth (Agkistrodon piscivorus) and the black racer (Coluber constrictor) as our class mascot. A mascot should be something that is very common for the item it represents, thus the fact that our class encountered these two snakes the most often on our field trips make the choice logical. However, given that A. piscivorus is poisonous and that no one had the chance to physically handle one, made choosing C. constrictor even easier.

Displaying 2015-04-29 15.43.07.jpgHere are some other things that aided me in choosing Coluber constrictor as our class mascot. First off, I learned how the black racer got its name . . . because it is an extremely fast and elusive snake! In fact, on two separate occasions C. constrictor was so fast and elusive that we couldn't catch it at all. Black racers are one of the fastest snakes around, which amazed me because they don't even have limbs yet they can move faster than many animals with four limbs! This ability makes the open ground the perfect habitat for C. constrictor, yet they tend to remain relatively close to underbrush so they can quickly get to cover if needed. Furthermore, despite being such aggressive snakes, I never realized how an animal that is plain black could be so beautiful. Its all black body with smooth scales give it a very sleek look with a simplistic beauty. C. constrictor's beauty was magnified even more so at Donnelley Wildlife Refuge, where a classmate found a black racer that was getting ready to molt making its eyes and parts of its belly baby blue. This black racer was extremely eye appealing and definitely still is the coolest looking snake I've ever seen in the wild.

This being said, the black racer should be our class mascot based on three undeniable reasons: it was the most common snake we found in the field, its impressive quickness and elusiveness, and its unadorned beauty. Need there be any other reason!? So I hereby nominate Coluber constrictor to be our herpetology class mascot.
Click here for video of how fast and elusive black racers are

Our Class Mascot: Anolis carolinensis

Our class mascot should be the omnipresent Carolina anole or Anolis carolinensis not because it is the most amazing animal but because it is such a big part of the studies of every South Carolina herpetologist. Carolina anoles are the most common herp in all of South Carolina and many people who grew up in the south can remember chasing and catching these little critters when they were younger. When we as a class go out into the field to pursue large and interesting herps everyone stumbles across an anole scampering across the ground or a tree. A mascot should not be the craziest or meanest animal in the area but rather the most common and recognizable animal. That sums up the Carolina anole, a creature that can be found from porches to walls and from forest trees to brush on the ground. For these reasons the small yet charismatic Caronlina anole should be our class mascot

Class Mascot: The Southern Leopard Frog


 I believe that Lithobates sphenacephalus, or the Southern Leopard Frog should be our class mascot. 



Reason One
Lithobates sphenacephalus is a long, slender frog with powerful hind limbs.They have golden colored dorsolateral ridges on both sides of their body that extend the full length. However, their most distinctive feature is their large, dark round spots that resemble those of a large cat. Given their distinguishable pattern and shape, I am positive that the entire class could correctly identify these frogs. Their iconic appearance is one reason this frog should be our mascot.

Reason Two 
The Southern Leopard Frog, abundant throughout the eastern United States, can be found just about anywhere near shallow water. Southern Leopard Frogs are nocturnal meaning they are active at night and rest during the day. However, this did not stop us from finding these frogs on two different occasions. The fact that we were able to capture these frogs during their 'night time' shows how abundant these frogs are in South Carolina.

Reason Three
These frogs also are very beneficial for humans. Not only do Southern Leopard Frogs eat a lot of pesky insects that humans dislike such as mosquitoes, they also serve as cadavers for students to dissect and learn about science.

The Southern Leopard Frog is a highly distinguishable and abundant frog that should be our class mascot.

Sex Ratio Bias of Tuatara and Risks of Extinction

This article deals with the sexual determination at play in tuataras and how this has a negative effect on their survival, especially in environments such as isolated islands or otherwise divided land.

 The primary issue is male bias in the animals that cause a relative lack of females, and how this has more of a negative affect than the reverse of the problem.  With more males than females, there are less reproducers overall than in comparison with an even split or with the female heavy equivalent.  Males also compete for females in tuataras, meaning during times of male bias there will be fiercer competition for mates resulting in some injuries and possibly loss of fitness leading to death.  In reptiles with temperature dependent sex determination, the process usually produced females at higher temperatures as the article states either male to female, or female to male to female as temperature increases.

The next issue with this bias is in the case of positive feedback from the process resulting in increasing the current trend.  In this case, majority male societies for tuatara generally continue the trend and produce more males as an effect.  In the case of the data gathered, three factors contributed to this gender skew and only increase said bias over time.  Decreasing body condition of adults, reduced adult survival, and shifts in hatchling sex ratio due to climate change.
The experiment to study these effects was largely data collection of tuatara, in this case on North Brother Island wildlife sanctuary.  Individuals were captured, measured and given permanent unique marks then released.  Furthermore this test went on for twenty years and it was hypothesized that unmarked adults after the first ten years of testing were likely children of the first generations captured.  One of the larger issues found during the experiment was the comparative speed and subtle nature of young tuatara meaning less were caught compared to adults.
 
The mark and recapture results show that male bias has further increased overtime in this area from 1.5:1 male to female sex ratio in 1988 to 2.3:1 male female sex ratio.  Also measured when caught, it seems over time the body condition (mass, length) have gone down during this period meaning reduced fitness.  In a problematic nature adding to the sex bias, males are typically larger than females and will out-compete their smaller rivals for food or other resources.  The reduction size, fitness, and nutrients have also shown in some cases a vastly reduced rate of reproduction in females.  Some solutions are proposed in the paper such as assistance of juvenile females to make sure they are large and fit before facing competition, or artificial incubation to ensure more females, but all are short term and won't help resolve the problem without constant work. 

As most in the class are aware, tuatara are the last remaining genus of the Rhychocephalia, and are a relatively ancient group at that indicating a unique section of reptiles.  The process involved in the paper also is similar to general methods that could be used for other endangered species as well in broader terms.

Citation:
Grayson, Kristine L.; Mitchell, Nicola J.; Monks, Joanne M.; Keall, Susan N.; Wilson, Joanna N.; Nelson, Nicola J. PLoS ONE. Apr2014, Vol. 9 Issue 4, p1-10. 10p. DOI: 10.1371/journal.pone.0094214.

http://eds.a.ebscohost.com.nuncio.cofc.edu/eds/pdfviewer/pdfviewer?sid=9125338f-6332-42e2-bd13-6c8e340064cb%40sessionmgr4004&vid=0&hid=4110

Herps in Pop Culture: Scientific Inaccuracies with Jurassic World

EVERYTHING WRONG WITH JURASSIC PARK/WORLD

While I have always personally enjoyed the Jurassic Park Series, in fact, so much so that as a young girl I aspired to be a paleontologist. Whilst my love for Jurassic Park is strong enough to look past the inaccuracies and just enjoy the ride, I still feel that as a "scientific based" movie, it has a duty to provide truth to the public. As Jaws did for the shark, Jurassic Park has given us falsified evidence to provide a more dramatic movie. Even in 1993, with the first Jurassic Park, scientists were aware of and publishing the evidence of feathers with dinosaurs. Now, armed with a militia of evidence and scientific discoveries, Jurassic World had an opportunity to showcase the REAL DINOSAUR to the public. I give you a summarized version of 3 things wrong with Jurassic World.
  1. Why are there no feathers on any of the dinosaurs? It is a scientific fact that a majority of dinosaurs, to include Raptors, had feathers. Feathers are merely modified scales, and for ancient large reptiles, could be in part, what provided them warmth for thermoregulation.

2. Genetic Testing: Where in the world did this Dr. Frankenstein study? Why would you even use frog DNA? The fact is, even if we found undamaged dinosaur DNA, scientists would never consider a Lissaamphibian over an Amniota. If you were to splice the DNA of a dinosaur with a close relative, it would make much more sense to use a bird. Even a mammal would be better suited than an Anuran!
Also as a side note: In this picture here we can see a reddish goo (blood perhaps) around this baby dinosaur. Why is there blood in the amniotic egg? It is an egg, there is no blood filled placenta. 

3. The Name itself: JURASSIC PARK. Although a catchy name, most of the dinosaurs featured in this film did not even exist during the Jurassic Period! For example, Tyrannosaurus Rex, Velociraptor, and Triceratops were all around during the Cretaceous Period! May I suggest Mesozoic Park?
After all is said and done, I will still be that nerdy kid, hunched in the movie theatre seat with popcorn and gummy bears, squealing with glee while feeling my childhood being restored. Unlike the young me, I will be going in with a skeptical mind and fueled with knowledge from my Herpetology class :-)

Tuesday, April 28, 2015

CLASS MASCOT NOMINATIONS
Heterodon platyrhinos ~Eastern hognose
!!!!! LOOK HOW SCARY!!!!!

So Why Should You Vote for This Sensationally Special Serpent?
  1. Well-trained in Shakespearean acting, particularly Hamlet
  2. Amazing mimicking skills
  3. So adorable
  4. This guy was so incredibly photogenic
  5. Bravery
  6. SUPER CUDDLY!! He may look menacing, but they very rarely bite humans
  7. He wags his tail in excitement to see you!
  8. For all you fishermen out there, you can relate to this snake. This member of Dipsadidae has rear fanged teeth that act as fish hooks for puncturing and capturing prey (like toads and salamanders)
  9. Important ecological niche
  10. Did I mention how stinking cute this little "puff adder" is?!
Play dead.. good boy!"To be or not to be, that is the question.."



Mascot Nomination: Florida Softshell

During the trip to TSA, I learned about the status of the Yangtze giant softshell, Rafetus swinhoei. This specimen is the world's largest fresh water softshell, and unfortunately the rarest, with only four known specimens. Two males inhabit separate lakes in Vietnam, while one male and one female reside in China's Suzhou Zoo. The two Chinese specimens have mated numerous times, with the female laying several clutches...all which have been infertile. The Chinese male has been proclaimed to either not being capable of copulation and insemination, or not producing viable sperm.  Due to political discrepancies, the probability of the female being able to mate with one of the other two male specimens is improbable, leaving the fate of this species to another gloomy human-caused extinction.

In honor of, and to impede this fate on our local species, I think the Florida softshell would be a great mascot for the class.  Although I would love to pick a really awesome, jazzy, flamboyant species to represent how cool herps are, I think in choosing a species of concern, we can not only consider how cool they are, but also how important they in conservation.

The Florida softshell, Apalone ferox,  is a South Carolina species of concern. It's size can range from approximately six inches to two feet, depending on the sex, females being larger. Of course, this is nothing in comparison to the Yangtze, which can reach over three feet.


The species isn't a thrill to look at, isn't a fiery red, or of colossal size (although largest of North American softshells), but does have a textured shell consisting of flattened hemispheres. The young are somewhat stylish, with what I deem a green/brown cheetah-print shell.

They're referred to as animated aquatic pancakes, with sharp claws and mandibles, deserving respect. If in which doesn't make you rethink your choices, you should.

Vote Florida Softshell!

Green Sea Turtle As our Class Mascot!

Green Sea Turtle As our Class Mascot!

Ok I don’t think anyone can deny that all sea turtles are amazing. Here are a few reasons why.....
  1. Firstly turtles are ancient, with the oldest known sea turtle fossils dated about 150 million years ago.
  2. Turtles understand the phrase “home is where the heart is” because female turtles return to the same nesting grounds where they themselves were born. Internal GPS - say what?
  3. They live in the ocean, and who wouldn't want to live there?
  4. Gender is determined by temperature! Woah
  5. Baby sea turtles never meet their parents, growing up is all based on instinct alone.
  6. They are huge and come from ping pong size eggs
  7. There are 7 species of sea turtle are endangered :( Survival rate is about 1% from the nest into adulthood.
  8. Turtles cry!? But not because their sad but because they shed excess salt from their eyes.

9. Most cutest thing you have seen all day
10. Their in trouble and it’s our fault.  https://www.youtube.com/watch?v=t-KmQ6pGxg4 
11. Can anyone deny their cuteness

New hatching demonstrate survival of the fittest


Ok I think I have proven why sea turtles in general are awesome. Now to explain why the green sea turtle should be our mascot. It’s a hard choice to pick which of the 7 sea turtles should be our mascot, however only one truly stands out - Chelonia mydas, the Green Sea Turtle.

  1. One of the most easily distinguished from other sea turtles.
  2. Can grow up to 1.5 meters in length and about 500 lbs, second largest after the leatherback.
  3. Can reach a speed up to 35 mph.
  4. Distributed worldwide and nest in more than 80 countries
  5. Regularly come to shore to bask, however this occurs only in Hawaii, and the Galapagos Islands
  6. Receive their name by the color of their sub-dermal body fat rather than their actual color which is a blend of different colors including brown, dark olive or gray.
  7. Adult green sea turtles are herbivorous, unlike most other sea turtles.
  8. Plus they are so photogenic, here's one in the Philippines photo bombing a group photo!



Balto the Magnificent

Balto.

You've all heard of him--the Siberian husky that led his team on the epic journey from Nenana, Alaska to Nome, Alaska with diphtheria antitoxin to squash a disease outbreak. This run is commemorated by a statue of him in Central Park and an annual sled dog race.

It is this spirit of exploration and adventure that made the spunky yellow-bellied slider (Trachemys scripta) that we discovered at Dixie Plantation the perfect namesake and candidate for our class mascot.

Allow me to remind you of his handsomeness:



Let me list the reasons why he should be our class mascot: 
  1. "Look at those sexy claw." - Dr. Welch
  2. This is the only critter that both lab sections got to interact with.
  3. He obviously loves us, as evidenced by the fact that he allowed himself to be caught again for the Thursday lab class.
  4. Turtles are an easy sell to outsiders.
  5. Balto the husky is a national hero.
  6. Our Balto also deserves to be a national hero (or at the very least a classroom hero). 
  7. LOOK AT THOSE SEXY CLAWS
  8. He is older and wiser than most of the other critters we've caught.
  9. We found him at Dixie Plantation, a College of Charleston institution.
  10. He is the only species that I consistently get right on lab tests.
For these reasons and I'm sure many more, Balto should be our class mascot--I hope you agree!

Article review

In the article “Amphibian Communities in Natural and Constructed Ridge Top Wetlands With Implications for Wetland Construction.”, scientists Robert Denton and Stephen Richter evaluate how natural wetlands differ from constructed wetlands and what types of amphibians are found in each in Kentucky. Denton and Richter used dip nets to collect amphibians and all of those that were captured were larvae, with the exception of the adult paedomorphic eastern newts. They also looked to see if the wetland hydrology was ephemeral or permanent. Results of the study showed that species richness and evenness did not differ between natural and constructed wetlands but they types of amphibians found did differ. In constructed wetlands, more predatory amphibians were found when compared to natural wetlands. Constructed wetlands were also not able to support the amphibians that utilize an ephemeral, and consequently natural in their area of study, wetland. Natural wetlands in Kentucky are shallow and ephemeral while constructed wetlands are deeper and permanent. Allowing different species to thrive in each.


Kentucky has lost about 81% of its natural wetlands. There is now wetland conservation and constructed wetlands to combat the amphibian loss associated with that huge loss. The study that Denton and Richter performed allows us to see the difference between constructed and natural wetlands. While we, as humans, do not see a huge difference, that species that inhabit wetlands definitely do. Through understanding how the species react to different types of wetlands, we can put forth proper regulations so that the constructed wetlands more closely resemble their natural counterparts. 

Denton, Robert D., and Stephen C. Richter. "Amphibian Communities in Natural and Constructed Ridge Top Wetlands with Implications for Wetland Construction." The Journal of Wildlife Management 77.5 (2013): 886-96. Web.

An overview of the symbiosis between Ambystoma maculatum and Oophila amblystomatis

In recent studies, it has been shown that a symbiosis exists between the green alga Oophila amblystomatis and the developing embryo of Ambystoma maculatum, also known as the spotted salamander. In this relationship, the algae resides in the embryo's egg and makes use of it's nitrogen-rich waste. In return, the algae supplies the embryo with photosynthetic oxygen and carbohydrates. The increased oxygen levels benefit the embryos by speeding up development, stimulating simultaneous hatching, and decreasing embryo mortality. Previous studies have indicated that the algae inhabit the eggs shortly after deposition and their numbers drastically increase in the earlier stages of development. This is followed by the algae becoming immobile and congregating in the inner egg envelope right next to the embryo. The purpose of the recent experiment conducted by Erin Graham, Zaid McKie-Krisberg, and Robert Sanders was to track levels of carbon transfer between the algae and salamander egg throughout development. A. maculatum eggs were collected and incubated in the lab in 8C fresh water on a light/dark cycle of 12 hours. Embryo stage was determined using two previously used methods and the outcomes were compared. Fixed carbon translocation was measured in the eggs at six points in the later stages of development. The results of this study support the previous research and also determined that the algae began giving carbon to the embryo during the middle tailbud period of development (stages 26-30), but this was only observed in 20% of samples. Peak carbon transfer was observed in stages 31-35 with 87% of samples. This was followed by a decline and by five days prior to hatching 0% of samples showed carbon transfer. The researchers conclude this trend is most likely due to the rapid growth of the algae in early stages, which eventually settles and stabilizes in the inner egg envelope where translocation takes place. Additionally, the decline of translocation in the latest stages of development is due to the thinning and eventual bursting of the egg envelope in preparation for hatching. 
This study is an important contribution to the understanding of how organisms interact symbiotically. This relationship gives the spotted salamander a competitive advantage to other salamanders that do not have supplemented nutrients. Not only can this help the embryo survive until hatching, but it can also produce a stronger individual that can better survive in harsh conditions after hatching. Larval salamanders can be especially sensitive to aquatic conditions and competition for resources as well as predation both inter and intra-specifically. The increased hatching size that may be a result of algae-supplemented nutrients could help these individuals better compete and survive to maturing so that they can reproduce. I think it would be interesting to do similar studies on other salamander or anuran embryos to determine if this type of relationship exists elsewhere. 
The image above is of a spotted salamander that has just laid her eggs in a body of water that may contain Oophila amblystomatis.

source: Graham, Erin R., Zaid M. McKie-Krisberg, and Robert W. Sanders. "Photosynthetic carbon from algal symbionts peaks during the latter stages of embryonic development in the salamander Ambystoma maculatum." BMC Research Notes 7 (2014): 764. Academic OneFile. Web. 27 Apr. 2015.

Monday, April 27, 2015

Global Sea Turtle Resilience to Climate Change

            Many people are well aware of the sea turtle conservation efforts that have been implemented in the past decade. Six of the seven marine turtle species are considered threatened or endangered worldwide. The past threats to turtle populations can be attributed primarily to fisheries, illegal markets, and coastal development. However, the future holds an even greater potential threat to marine turtles: climate change. A primary concern is that climate change will compound the threats that sea turtles already face. Turtles are extremely vulnerable to environmental temperature changes because of their rather complex life history. Climate change could detrimentally affect both hatchling and adult turtles in a variety of ways. The most apparent threat involves multiple aspects of their reproduction. Marine turtles exhibit temperature-dependent sex determination. Elevated temperatures could feminize populations and possibly decease reproductive success overall. Other concerns include the loss of nesting beaches and changes in food availability.
            Resilience can be described as a species’ ability to adapt or resist to environmental change. Fuentes and colleagues set out to quantify the resilience of marine turtle species around the world. More specifically, they sought to better understand the factors that are important to genetic diversity, geographic distribution and breeding population size. The researchers consulted with over 200 of the world’s leading marine turtle experts to obtain the resilience criteria to be used in their analysis. The consultants were knowledgeable of 58 marine turtle populations around the world, which are termed Regional Management Units (RMU’s). The goal of the researchers is to determine which RMU’s could be most threatened by climate change and to identify the factors that make these populations susceptible.
            The study assessed two types of traits that affect population characteristics: population trends/threats to genetic diversity and non-climactic threats (fisheries, coastal development, pollution, etc). The most resilient RMU’s consisted of leatherback and green sea turtle populations in the Atlantic and Indian Oceans. Hawksbill and loggerhead RMU’s were found to be the least resilient, witht he Indian Ocean hosting the largest proportion of least resilient RMU’s. According to the results, the expert correspondents agree that rookery vulnerability and nonclimate threats are the most important variables to the resilience of populations facing climate change. A rookery refers to the nesting population of turtles. Thus, maintaining prime nesting areas is vital for the persistence of RMU’s. Development of the coast along the southeast United States in burgeoning and will pose a serious threat to rookery vulnerability in combination with climate change and other variables. The two most influential non climatic threats to marine turtle resilience were found to be fishery bycatch and coastal development. For six of the least resilient RMU’s, expert correspondents reported fishery bycatch as the most common threat.


            Not only are sea turtles captivating animals, but they are also keystone marine species. They cycle nutrients and bolster coral reef diversity by consuming algae, sponges and corals that compete with each other for space. Quantifying resilience is a complicated task, but Fuentes and colleagues’ study is a great step towards understanding the factors that influence individual populations’ adaptability to changing environmental conditions. It is imperative that we devise future conservation strategies that predict the impact of climate change. Such strategies will have to cater to the deficits of individual populations to adapt to changing conditions.

Source: Fuentes, Mariana M. P. B., David A. Pike, Andrew Dimatteo, and Bryan P. Wallace. "Resilience of Marine Turtle Regional Management Units to Climate Change." Global Change Biology 19 (2013): 1399-406. Print.