We are going to see what methods there are to sex snakes, but the most common and used is sexing by cloacal probe.
sexing methods
Before looking at the probe system that we use, we are going to do a quick review of other snake sexing systems that can be used.
- Visual sexing: It is the least effective system of all, although it was traditionally used for years before having the necessary machinery to carry out other tests. This system is based on looking at the differences that there are at first glance between the sexes. The males have the widest tail just after the cloaca, it is also flatter than that of the females. Also, females are larger than males, especially with larger diameter.
- Scale counting: This system requires waiting for the snake to shed its skin and is also not a particularly reliable method. It is about counting the sub-caudal scales that in males are more than in females.
- Endoscopy sexing is the most expensive technique and involves some risk for the animal, but it is the only one that is 100% reliable since it involves seeing the animal’s gonads in situ through a small surgical procedure and cameras. This method is often used by people with very expensive animals who need to pair them quickly.
- Ultrasound sexing is a minimally invasive and fairly reliable method as long as the animal has reached sexual maturity and the gonads can be identified.
In males we can see the testicles inside the coelomic cavity or look at the area of the hemipenes, which are structures that they present for copulation that are located inside the animal in the portion below the cloaca.
In females the ovaries can be distinguished. It will be easier to see them if they are with bone follicles if you are ovulating and sometimes you can even see the eggs already forming.
- Probe sexing of snakes is one of the simplest and most reliable methods, which is why it is routinely used in specialized veterinary centers.
The first thing you should know is that to perform sexing it is better to wait until the snake is already a certain size. If it is very small we can inadvertently hurt it. The probe is inserted through the snake’s cloaca and a rounded and lubricated one is always used, it is the best option to avoid damaging it. It is known if it is male or female depending on the space that the probe can travel within the flow.
- Many of you will wonder about Sexing through DNA genetics, here you have to make a point and that is that most reptiles do not have sexual determination by DNA, since an embryo inside the egg already has a DNA and evolves to male or female depending on the temperature of its incubation. Furthermore, it is difficult to find established genomic sequences for most reptiles and amphibians.
As a curiosity to know that the XY system is normally used to name the genes that will give rise to the sex of the individual. As we already know, the “Y” chromosome is the male chromosome, while the “X” chromosome is the female, homogametic individuals (XX) will be female and heterogametic individuals (XY) will be male. There is another system in some animal species called: ZW and things are contrary. The “Z” chromosome is male and the “W” is female, likewise, homogametic individuals (ZZ) will be male while heterogametic individuals (ZW) will be female. Within these systems we find in the “XY” some species of lizards and turtles, while in the “ZW” we find snakes, amphisbaena and some species of lizards and turtles.
