Snake Sexing Methods
© Alan W. Zulich
One of the matters commonly misunderstood by novice snake enthusiasts is that most snakes can be sexed accurately and with minimal trauma to the animal. This paper will discuss two methods of sexing adult and juvenile snakes - probing and "popping" of the hemipenis.
to the cloaca, a pair of hemipenes are present in male snakes.
SEX DETERMINATION BY PROBING
can be determined in snakes by probing posterior to the cloaca, to determine the
presence of hemipenes. Typical sexing probes are stainless steel and either ball-tipped
or tapered on the end.
The sexing process begins by selecting the probe of proper diameter. As mentioned above, the hemipenes are paired structures located on either side of the midline. By turning the snake over and visualizing their location and size, a proper probe diameter can be selected. Generally, a probe diameter equal to approximately one quarter of the anal plate is appropriate. Choice of too large a probe will prevent free movement of the probe within the hemipenis, while a probe too small will risk puncturing the posterior end of the hemipenis when probing.
After a probe is selected, it should be lightly lubricated with K-Y jelly, vaseline, mineral oil, or water. If the animal is to be probed just prior to breeding, care should be taken not to use a lubricant that contains a spermicide.
tip of the lubricated probe should then be placed in the cloaca, on either side
of the midline.
probe is then rotated anteriorly, with gentle downward pressure.
pressure should be maintained until posterior travel stops.
The probe is
then placed on top of the tail in the same position and depth it was inside the
of most species probe to a depth of approximately three subcaudal scales, and
almost always less than eight,
There are exceptions, and lists of typical probe depths for various species are given in other publications.
safer method of sexing juvenile snakes is the "popping" of the male
hemipenes. The animal is held inverted in the left hand, with gentle finger pressure
just forward of the cloaca. The ball of the right thumb is placed on the tail,
about twenty scales behind the cloaca. The right thumb is then rolled forward
toward the cloaca. This pressure on the tail will cause the hemipenes of the male
snake to be everted.