Carapace Chronicles


Plasma
August 11, 2010, 11:16 pm
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I am now on to the part of my project that involves running my plasma samples. I thought I would give you guys a brief overview of what I will be assessing the plasma for and why we test for them.

We get the plasma by spinning down the blood in a centrifuge and then removing the plasma layer from the red blood cell layer. Measuring the different chemicals in plasma is the only way to tell whether an animal is in organ failure without biopsies or surgery!

First, calcium. In trying to look at the differences between males and females, calcium levels should be higher in females that are actively reproducing. Calcium is also involved in cell membrane integrity and bone integrity. Phosphorus works together with calcium. Phosphorus inhibits calcium absorption. The best way to use calcium and phosphorus is from the ratio between the two. It can tell us about bone absorption and the health of the pathways that absorb and excrete them. A good ration is greater than 1.5 Ca: 1 Phosphorus.

The egg shell will be less sturdy during a Ca deficit in the mother.

Total proteins are a measure of the amount of protein in the blood. It is made up of albumin and globulin. Albumin functions to keep blood cells within the blood vessels and is also involved in tissue growth and healing. It can also be an indicator for liver and kidney function. Globulin is composed of antibodies and inflammatory proteins that help fight infection.

Uric acid is a parameter that is not measured in humans because we do not make it but it is very important in reptiles. This is the end-product of protein metabolism. It can also indicate the hydration status and dietary status. High uric acid can mean kidney failure, but can also mean that the animal just ate a high protein meal – and in a box turtle this usually means an invertebrate or fish.

Bile acids are a very important indicator of liver function. The acids are made in the liver so if the liver is compromised the bile acids production in the body will be compromised. Bile acids are involved in the breakdown of dietary fats.

Aspartate aminotransferase is an indicator of muscle health. It can also indicate organ health and is very helpful in diagnosing liver disease. Creatinine kinase (CK) is also an indicator of muscle health but it is less specific than aspartate aminotransferase. Generally, we use CK to determine if AST is high because of liver damage or due to muscle damage (if the CK is high then it is probably muscle damage).



The White Blood of the Turtle
July 23, 2010, 12:34 am
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Hello everyone! We have had a great week so far, I collected blood from turtle number 200 today. It’s been a good time, very long hikes and hot weather! I have found some better ways to get a turtle to say “AH!”. The CRESO kids have been so helpful, with taking oral swabs and also with helping me with lab work. My time spent analyzing blood samples has been lessened by all the kids and I have been able to spend more time analyzing my CBCs.

Speaking of CBCs, I thought I would give you guys a little idea about what cells I am looking for in the blood smear and what their function is in the blood.

First, the monocyte. Monocytes are the largest white blood cells in the blood. The cytoplasm of a monocyte stains dark blue-gray and the nucleus is pink. They are circulating macrophages and move to sights of infection to eat bacteria and fungi.

Second, the heterophil. Heterophils are pink cells that have a dark pink nucleus and a lighter pink cytoplasm. The nucleus is off-center and usually sits on the edge of the cell.   They are the first line of defense against bacterial infections.

Third, the eosinophil. Eosinophils are large round cells with spherical granules that are pink in color. They resemble heterophils but the cytoplasm is filled with granules. They function in fighting parasites and in allergic reactions.

Fourth, the basophil. Basophils are round cells that contain very dense, dark purple granules that often obscure the nucleus. They resemble azurophils, the fifth blood cell, however, the nucleus in azurophils is always present and there are few granules in cytoplasm.

A Basophil

**I apologize for the poor quality of the pictures, they were taken through my microscope!**



All in a Day’s Work
July 17, 2010, 6:26 pm
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The processing of turtles is harder than it sounds! Here is an idea of a typical turtle find from beginning to end. As you know we have these spectacular dogs that do all the hard work for us. As they find them, tape is first placed around the shell and each turtle is given a temporary ID, we use the generic ABCs.

We have runner “books” that are then filled out with the microhabitat, such as under leaves, in log jam, etc, the dog that caught it, time it was caught, temporary ID, and GPS coordinates.

For each turtle we take length, width, and height measurements.

We also count the annuli, the rings on the scutes of the turtle to tell their age much like the rings of a tree, and determine whether they are smooth, somewhat smooth, or well defined. Generally as the turtle gets older the annuli will become more smooth. After 20 years of age it is really hard to determine the age of the turtle because the shell is almost completely smooth.

We also record the weight and hopefully if we see the turtle we can get a look at the eye color. As you’ve read before, eye color can be a determinant of sex.   But not that often.

After the turtle is done being processed, I take blood, get an oral swab, and hopefully do a physical exam.

Once all the turtles have been processed, they are placed back at their GPS location where they were found. 



Born to track
July 7, 2010, 10:13 pm
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Pardon my absence! I’ve had a busy few weeks writing my abstract and doing blood work. It’s been tedious but I’m getting the hang of the different types of white-blood cells. Beginning on Monday, the turtle-tracking dogs will be back and we will be in the field for 8 days trying to catch as many turtles as possible! I want to tell you a little bit about these guys because they are very, very talented and fantastic to watch.

John Rucker is the master of these turtle-tracking Boykin Spaniels. There are anywhere from 4-8 dogs that track at any given time. The A-team is made up of Jinny-wren, J-Byrd, Snapper, Sparky, and Gretta. The B-team of Rose, Mink, and Rooster. Sparky is the oldest living turtle dog on the team and is a legend in his field. We have gotten to know each other pretty well as it’s been so hot and he has hung out with me. Jinny-wren is the current #1 turtle dog on the A-team. There is a new batch of puppies that are just beginning their training to carry on the turtle legacy.

We start out early in the morning to minimize the Southern heat. First, the high-schoolers participating in the project will douse all the dogs in water to cool them down before the team sets off.

We follow them all over our study site as they run, nose to ground, sniffing for the scent of the box turtle. When it hasn’t rained in a long time it is harder for the dogs to track the turtles because they hunker down in the leaves and don’t move. We are in that right now, it hasn’t rained in a long time but the dogs still manage to pull 10-15 turtles out of the site in a hour.

Once a turtle is found, whether it be by a log or under leaves, the turtle is removed from them and John and the lucky dog celebrate together. It is so neat to watch, both John and the dog get very excited and you can tell they are both pleased.

Watching these dogs is something special. Hopefully when we go out into the field next week I will be able to get a video of them in action to post on here so you guys can see. Without them, human searches average roughly 0.8 turtles an hour. This summer we have been averaging roughly 8 turtles an hour. The difference is extraordinary! I thank these dogs everyday for what they do and the fact that they have provided me with a fantastic number of turtles!



Population Decline
June 26, 2010, 6:34 pm
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It’s been an exciting week! We had the turtle tracking dogs here for four days and I’ve reach 131 turtles! I been really grateful to have some help from the high school students with CRESO. They’ve been really great and have helped me get things done faster and more efficiently!

I thought I would segway into the population decline of reptiles. The decline of amphibians has been well-publicized and reptiles are in the same peril. Reptiles and amphibians are environmental indicators and can often tell us the health of an ecosystem before we know it. For this reason it is important to determine the causes of the declines and help prevent further die-offs.

Many people have found frogs with an extra leg or a tail after the tadpole stage, however, the same hasn’t been found in reptiles. This has resulted in less education of the public about reptilian declines. They can be due to disease, habitat fragmentation, and the other stresses they encounter in the environment. As suburbia has expanded, the stresses on the turtles have increased exponentially causing more susceptibility for infection. With this and the entrance of novel diseases, the turtle population is declining at an extremely fast rate. As I mentioned before, we are testing for some of these diseases in this population.

In addition, my study site has sivilculture and clear-cut sites within it. In the past three years, the turtles here have been affected by these habitat changes, a drought, and a new subdivision built on one edge. There is also a quarry nearby. These turtles experience a great deal of different stressors and could be more at risk for infection!

With population declines occurring in reptiles and amphibians, health surveys have become very important!



Catchy Disease
June 25, 2010, 12:50 am
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Things are going well in the field, although the heat is really slowing everything down.  Yes, extreme heat without rain can actually slow a reptile down.  We reached our 100th turtle this week and sampling is going well. I’m having a really good time and becoming more and more comfortable with the turtles despite the heat!

I thought I would take some time out to share how I got involved in this project.  My mentor, Dr. Matt Allender, is studying diseases that have the potential to be fatal to turtles.  Ranavirus is one of the diseases he is most interested in. It is one of the causes of well-publicized amphibian declines across the world.  It has also been attributed to some turtle die-offs in the world.

We are collecting oral swabs from the box turtles, and also some species of aquatic turtles, so that we can run a PCR (polymerase chain reaction) to determine if a turtle has the disease. Collecting these samples have been challenging, try and get a turtle to say AHH!

Through the physical exam I perform, I look for signs of disease in a turtle, such as spots on the roof of their mouth that might indicate sickness. In addition to spots in the mouth, turtles with Ranavirus appear like they have a cold – runny eyes, snotty noses, and a general feeling of sickness.



When this disease first appears in a population, it likely leads to massive die-offs that could cause population declines.  This is why it so important to look for the answers of where, why, when, and who gets these diseases.

For more information I have included a link to an article on Ranavirus infections in box turtles,  http://www.jwildlifedis.org/cgi/content/full/44/4/851

Enjoy!



The Eastern Box Turtle
June 16, 2010, 3:37 pm
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Eastern Box Turtles are part of a group known as the hinge-shelled turtles, or box turtles. They are found only in the Eastern United States and are a purely land animal. The species I am studying, Terrapene carolina carolina, is one of 5 subspecies of the Eastern box turtle.

The “hinge” is the unique characteristic of this family. It is located on the plastron, or the bottom part of the shell, and when combined with the large, domed carapace, or the top part of the shell, it will allow for total closure of the shell.

The carapace is normally brown to almost black with orange or yellow splotches covering the shell. There is no difference between males and females in the color of the shell. Below you can see variation in the different patterns on the carapace.

There are two different ways to tell a male box turtle from a female box turtle. First, males have a concave plastron that allows an easier time mating while the female plastron is flatter. It’s a hard shape to capture in a picture, but in the picture above, the word “hinge” sits in the concave divot on the plastron.

Another way to tell males and females apart is by eye color. The males typically have red eyes and the females have a more brown version. However, there are turtles out there that don’t fit this mold! Also, often when catching turtles they often retreat into their shell and we never see their eye color so the plastron then becomes the easiest way of determining sex. Below, the first picture is of a female box turtle peeking out of her shell and you can see her brown eyes, following that is a male with his red eyes.

Our box turtles prefer forested land and can often be found in ravines or on ridgetops. They are usually found among leaf litter. If we get lucky and it has rained, we can find them crossing roads, in fields, or near streams. They also like fallen logs and moistened ground to dig up their meals, such as worms, snails, and other bugs. In fact the other day we caught one that was eating a beetle! They also eat berries, flowers, and mushrooms.

As you can see the Eastern box turtle is a fabulous little turtle, or at least I think so!




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