Fourth week of incubation and second clutch

The egg seen from above

The same egg from side to side

Another egg seen from above

 The same egg from side to side

 

There has been a problem. I have to add water from time to time to the incubator. When I do it I switch off the heater. Last thursday I forgott to switch it on when I finished. This morning when I opened it the temperature was 20ºC instead of 30ºC but I don't think it affects the embryos. Two years ago I incubated one egg outdoors and it reached 12ºC and almost every night it reached the 20ºC.

 This summer is strange. Since the beginning of June we have afternoon thunderstoms every other day and temperatures are lower than usual, especially nocturnal ones. Today it is nearly a month since the Clemmys layed the first clutch. I palpated the eggs some weeks ago, but the female retained them until yesterday when we had a warmer day.

 

The female always nests in the same places, one in the west side of the pond, the other in the east side. She always changes from one to another among two consecutive clutches. It seems she somehow remembers where she layed the fisrt clutch and decides  to lay the second one in a distant place. Maybe it is a way to lower the chances of nest predation, or a way to avoid digging out the eggs of the first clucth laying the second one. It might also be a way to increase the chances of nest survival because of different microclimates in different places, which could also affect the sex of the hatchlings. 

For the second clutch she chose the west side. And there have been some problems. She began digging the nest yesterday evening (I saw her at 21:30). This morning, at 10:00, she was still digging in the same place.  12 hour making a nest and still not finished. 

According to David Carroll descriptions in his books, this turtle lays the eggs during the night to avoid the heat of the sun. A dark and small turtle can overheat easilly under the sun in land. About 10:00 the sun reached her
 

I doubted but finally  I picked her up to have a look. She dug a nest but there were no eggs. Could it be a dystocia? I left her in the same place again. When I came back a few minutes later I saw three eggs an no turtle. I saw her in the water section and I caught her. I palpated her and she was still carrying eggs. I put her in a bucket without water. While I was picking up the eggs my son told me the turtle was laying a fourth egg. It would have surelly been layed in the water if I had left the turtle in the pond. I palpated her again and this time I didn't feel eggs. 

Once I picked up the eggs I examined the nest chamber. It was very shallow. The earth was very hard.  When I disturbed her she just expelled the eggs and went to the water section carrying an egg that she would expell in less than two minutes.

A curious thing: the fourth egg has a shallow depression on the shell. I had seen this before

I had seen it in Terrapene carolina triunguis , in oxytocine induced clutches.

One possible explanation is pressure between the eggs in the coelomic cavity.

 

But if this was the explanation I think I would see it in the radiography, at least in some eggs. And it appears in all the eggs and exactly in the same place, dorsal as the eggs are layed. You can see it in the next pictures. If these were due to contact areas between the eggs, they  would show it in diferent locations, not all exactly in the same place.

 

I even thought if it could be some deformation of the passage of the eggs that caused it, but I discarded it when it happened with other terrapene. Always the same dent, the same size and exactly in the same place in freshly layed eggs. It dissapears during incubation.

I told about it to an expert chelonian keeper and his answer was quite logical: these are soft-shelled eggs. When they are being layed they collapse a little bit and a dent appears. Once incubation starts and the egg resorbs water the inner pressure increases and the dent dissappears.

Regarding Clemmys, also with solf-shelled eggs, I had never seen it in previous clutches. And only in one egg of today's clutch. The only difference with previous clutches is that they have been retained more than usual and that the eggs have been picked up just as they are layed.
 

I marked the eggs and put them in the incubator. This time I have weighted and measured them. I will repeat it by the end of incubation.

 

 

From top left to top right

1) 6g.  30,32mm x 18,31mm x 18,32mm
2) 6g.  29,30mm x 17,60mm x 18,16mm
3) 5g.  26,6mm x 18,28mm x 18,3mm
4) 5g.  26,43mm x 18,48mm x 18,28mm

Later, at 18:00, 8 hours after putting them to the incubator, the eggs start chalking, an indicator of fertility.

The fourth egg is still dented

 

Third week of incubation

The egg seen from above.

The egg seen from one side (keeping it in vertical position) 

 

 

Yesterday I palpated the female to check if she was still carrying eggs. She was. I also took a picture of her back end. I do not recall that the supracaudal scutes were so brown.  Maybe I didn't notice, but it could also be that in the process of wear/growth of the keratin layer the background color became more obvious in comparison to previous years. 

In the picture the turtle is wet, which increases the constrast between colors.

 

14th day of incubation

Second week of incubation.

External appearance

Now the light beam is directed ventrodorsally. Blood vessels can be seen in one side, near the end of the egg (top left in the picture)

 

Now the light beam is directed latero-laterally. The blood vessels can be seen in the lower part of the egg (bottom right in the picture)

When I made this picture I didn't rotate the egg. I leaned it on the thumb while keeping the egg in a vertical position. It seems that the embryo is forming near one of the poles of the egg, ventrally and lateral. I made a mistake not marking the top of the egg. Now I am not sure if the egg could have been slightly  rotated without noticing while handling it to take the pictures. It shouldn't be a problem for the embryo but now I am not sure if this is the position where the embryo started developing.  I will mark them for future pictures. I will also mark the eggs of the second clutch (wich I can already palpate) to compare the development.

Regarding egg handling, it is interesting what  A.C.Highfield wrote in  "Practical Encyclopedia of keeping and breeding Tortoises and Freshwater turtles" pg31.  He made experiments gently turning eggs in mid incubation. It didn't affect the egg viability, although some tortoises hatched turned.
He considers that it is a myth that you have to collect the eggs exactly in the same position they were buried. It is later, when the embryo is forming, that it is more suceptible to movement and rotation. 

I have made a quick search in internet about the effects of rotation of chelonian eggs during incubation but I didn't find any specific study. There is plenty of advice against rotating them and embrionary failures attributed to rotation but I couldn't find an specific study about it. I will have a look at the references in the books I have home.

I believe that the Clemmys eggs are in a stage where I have to be very careful when hadling them, and I do not intend to rotate them,  but it is good to know that it does not always mean the death of the tortoise.

7 days of incubation

It's 7 days since the incubation started. Externally they look like that

With the light of a torch I don't see any change since last week. The other eggs look the same.

First eggs 2014

After some cool and rainy weeks, Saturday was the first summer day of the year, with temperatures over 30ºC . Around 6 o'clock in the afternoon, the female was in the land area. I quickly moved away. If she noticed I was looking at her in that moment, she would flie away to the water. She always does. I had to go and when I came back at 9, she was already nesting. With this female, once nesting, she doesn´t mind being observed. In fact some years ago I took very close pictures of her while she was nesting.  
She nested under some plants, as usual.

 

 

I left her digging and I came back at midnight. She was still in the same place and I went to bed.
Next morning I was surprised to see how well hidden the nest was. If I had not seen the female nesting, I wouldn´t have seen it.

Picture of the place next morning

The same  picture  showing where the nest was

The female gets under the plants and then starts digging. The same behavior is shown in most of the pictures of previous years. This is why the plants look intact when she has finished. 

I wonder if this sort of plants, with a fast and invasive growth, would have destroyed the nest.

But there is no chance because I put the three eggs to the incubator

I will take pictures each week during the incubation to see the development . This first picture is 9 hours after the eggs were laid. 

12 hous later, at 30ºC, it seems that a white patch appears on the upper surface of the eggs.

Hopefully in about 45 days there will appear something like this

Ready to lay eggs

I palpated the female  15 days ago and I felt it carried eggs. When this females carries eggs, the skin in the inguinal area protudes as you can see in the picture. This could also mean obesity, but this time it meant eggs.

Since then we have had rainy days with cool temperatures, specially at night, below 10ºC. I guess she won't lay the eggs until the weather gets warmer.

I use this post to show the pictures of two other chelonians I saw in a well known building from Barcelona some weeks ago.  Each of them carries one column on its back.



The tortoise in the mountain side of the building

And the sea turtle in the sea side of the building

The building is the Sagrada Família , an architectural marvel designed by Antoni Gaudí i Cornet.
I had visited it 30 years ago, when there were just two sides build. Since they finished the inside I was looking forward to visit is again.  Gaudí used nature as an inspiration for his architecture. He said nature chooses the more fuctional and economical solutions to a problem. He designed a catedral full of light with plenty of architectural innovations, such as columns that branch out like trees .

 

The outside of the building is full of religious scenes sculptured in the stone. There are gargoyles inspired in different native animals: Tarentolas, lizards, salamanders, chamaleons, snails...

http://www.sagradafamiliagaudi.com/Vista%20General/Fachada%20Abside/Abside/Gargolas/Dragon.html
 

But in my opinion, when it becomes extraordinary is when you get inside. You get into a enormous space full of light and color, with columns that brach out and a ceiling full of light.  There is no need to know the architecture behind it, that is also impressive, to understand that Gaudí was a genius
 

I attach some pictures and links. As soon as the turtle lays the eggs I will come back to the blog thematic

 

It is worth visiting, but in case it is not posible there is also the chance of a virtual visit, from the inside and the outside.

http://www.sagradafamilia.cat/sf-eng/docs_instit/vvirtual.php?vv=1  

                                                


ANTONI GAUDÍ I CORNET

Cleaning the pond

The vegetation is an esential part of the pond as it filters water. The sand of the bottom is also important as it suports the plants roots and allows bacteria and invertebrates to play their role in cleaning the water.

The downside is that it grows and tends to colonize the entire pond. This spring there were cattail sprouts everywhere and the depth of the pond had reduced because of the roots thikness. 

 

Once empty

The original level at some point is 5 cm below

I cut the roots until I reached the original level and I could see the stones. I also  removed the surplus cattails. 

 

                                  



A kind of earthworms but acquatic. They surely help to remove the organic matter.
 

Once the excess of vegetation is removed

 

 

Another problem is that although the pond is filled to the brim, the day after the level has dropped about 10cm. I don't think it is a hole. Rather, I think it may be due to a problem of capilatity through areas where water and ground contact.