As an ancient and mysterious creature, turtles have attracted the attention of countless enthusiasts. However, one of the most challenging issues for breeders and researchers is how to accurately determine the sex of a turtle. The identification of turtle sex is not only important for scientific research, but also crucial for population management and individual care. This article aims to provide a comprehensive guide to help you understand and master the scientific principles and practical techniques of turtle sexing.

The importance of turtle sexing

Turtle sexing plays a vital role in population management and reproduction. The correct sex ratio is critical to maintaining the health and stability of tortoise populations, especially when protecting endangered populations and implementing captive breeding programs. In addition, gender identification is also the basis of scientific research and helps to understand the ecological habits, reproductive behavior and evolutionary mechanism of turtles.

Basic methods for gender determination

Turtle gender identification usually relies on observing the external morphological characteristics of the individual. Although these characteristics vary among different species of turtles, the following are the most commonly used and universally applicable criteria:

Shape of carapace and plastron: The plastron of male turtles usually There will be obvious depressions to accommodate the female's position during mating. The female's plastron is usually flatter, which is conducive to egg laying.

Tail size and shape: Male turtles usually have longer and slimmer tails than females. Thick and broad at the base of the tail. The tip position of the tail is also an important reference for identifying gender. The tip of the male turtle's tail is usually located on the outside of the buttocks, while the female turtle's tail tip is relatively close to the center of the body.

Location and shape of the cloaca: The cloaca is usually located near the tip of the tail in male turtles and closer to the edge of the carapace in female turtles.

Long forelimb claws: In some turtle species, the male's forelimb claws are longer and pointed, which helps in grabbing the female during mating.

Endoscopic Gendering

Coeloscopy can be used to determine the sex of young animals or The sex of an animal without obvious secondary sexual characteristics. Ideally, endoscopy should be performed under general anesthesia, although the technique can be performed using local anesthesia.

Femoral access for laparoscopy includes:

Develop an appropriate plan for analgesia, anesthesia, and cardiorespiratory monitoring.

Side or recumbent position.

Extend to the tail of the hind limb to expose the anterior femoral fossa.

Aseptically prepare the anterior femoral area and surrounding shell

Make a small skin incision in the center of the anterior femoral fossa.

The subcutaneous tissue and fat are dissected to expose the aponeurosis of the transversus and oblique muscles; the aponeurosis and body cavity membrane are incised using blunt and sharp dissection methods.

Insert the endoscope and view the gonads directly dorsally.

Conventional closure can be performed with absorbable sutures.

Skin closure can be done with sutures or surgical glue.

If sutures or glue are used, the turtles should be dry-reared separately for 24 to 48 hours

Identification with endoscopy and cystoscopy

Endoscopy of the gonads can also be performed through the cloaca/bladder. An advantage of this technique is that it usually does not require surgical anesthesia. One disadvantage of this technique is that uric acid deposits can hinder visualization. Furthermore, accessory vesicles can be highly vascularized and hinder visualization.

Measurement of hormone concentrations in sex for identification

In juvenile turtles, measurement of plasma testosterone concentration is also a useful method of determining sex. Rostral and colleagues found that endoscopically sexed male animals had significantly higher plasma testosterone concentrations than female animals. The agreement between the two methods was 98%. The FSH test has also proven useful in confirming sexual behavior. FSH can be injected into the body cavity, and blood is drawn 4 hours later to measure plasma testosterone. The concentration for males is 0.5 ng/mL, while for females it is 0.2 mg/mL.

The influence of species and age

It is worth noting that the gender of a turtle Characteristics usually become apparent after reaching sexual maturity. Therefore, the age and species of the turtle need to be considered when sexing it. The ages at which turtles reach sexual maturity vary widely among species, ranging from a few years to decades, and the accuracy of gender identification will vary accordingly.