My study: A difference seen between snake sheds of corn and kingsnake

My Florida kingsnake Flo

About corn snakes
The corn snake (Pantherophis gutattus) is a species of rat snake from North America, within the eastern and central area and get their name from being found close to corn barns where, they fed on rodents. They lack venom and therefore kill their prey via constriction which includes small mammals such as mice. As adults they can reach lengths of between 2 to 6ft and can live up to 23 years. Their docile nature, manageable size and varied coloration make them a popular pet species.

About kingsnakes
Kingsnakes (Lampropeltis sp.) are part of the colubrid family and have approximately 45 subspecies. They are constrictors and eat rodents and other (venomous) snakes such as rattlesnakes, due to their resistance to their venom. They are found in a variety of colors and some species such as the red kingsnake are often mistaken for the venomous coral snake; a rhyme such as red on yellow kills a fellow, red on black venom lack, aids in identification of species. (Note: Even though the rhyme is a helpful aid, please view any wild snake from a distance and leave handling to the professionals.)

Loki my corn snake

 What I did
For a piece of coursework for my third year, I had to do a series of photographs of increasing magnification on a chosen topic. I decided to focus on snakes and in particular corn and kingsnakes, due to them occupying similar ranges and in the field identification often being very difficult due to them disappearing and due to handling often being stressful on wild specimens. Therefore I decided to focus on snake sheds; snakes shed a process known as ecdysis and is seen in other species such as frogs and spiders. Their outer layer of skin (outer epidermal generation) is replaced by a new inner layer (keritinized (same material as your nails) epidermal generation) and is shed episodically over a period of 6 to 14 days.
I used the most recent sheds from my corn and kingsnake and proceeded to take an initial photo of the entire shed and then focusing on just the head and a section of the body scales with increasing levels of magnification, to see if any difference could be seen.

The snake sheds (The longest (corn snake) was 6ft1)

What I found
It was hard to see great difference between the specimens when a camera and microscope was used but some very interesting differences became apparent when I used the SEM (Scanning electron microscope) this takes images and very high magnification by scanning the samples with a beam of electrons, the electrons interact with the sample producing various signals that project the image.
Firstly I looked at the head samples, focusing particularly on the lens caps (the scale that covers the eye) and noticed that they were both different shapes and the outline of the eye/lens was different between the two. You can see from the pictures below that the corn snake's lens cap is rounder and the kingsnake has a more oval shape; You can also see the eye/lens outline (the darker inner circle line) is larger in the corn snake then in the kingsnake.

Corn snake lens cap. Magnification: x43

Kingsnake lens cap. Magnification: x41

  Next I focused on the body scales and again a interesting difference was seen, in the corn snake the tips of the scales had raised points and less elastic skin then the kingsnake which, had scales that had indents on the tips and more elasticated skin.

Corn snake scale with raised points. Magnification: x88

Corn snake raised point. Magnification: x1000

Kingsnake scale with indented tips. Magnification: x45

Kingsnake scale indented tip. Magnification: x470

Why are these differences present?
As my study did not require a full investigation, I can only speculate to why these differences occur; the kingsnake is a species that eats large meals and therefore the presence of more elastic skin would be advantageous, the kingsnake eats smaller meals and therefore does not need to expand to accommodate large meals. I can not explain why the indentations are present on the kingsnake scale but can possibly suggest a reason for the points on the corn snake which may be a grip aid during movement. Again the difference in lens cap is something that also requires further investigation but may represent different requirements for vision to meet hunting/survival needs. Even though I personally am not sure what these differences are for, they have provided a visual difference in identifying these two species via their sheds and therefore could be of interest to the scientific/herpetology community and warrant further study and something I would be interested in pursuing further.

As always thanks for taking the time to visit and read my blog and leave any thoughts in the comment box below and until next time Keep It Wild!!!