A method for visualizing of reproductive organs in immature small mammals using Soricidae (Insectivora) and Cricetidae (Rodentia) as an example

L.Ya. Saburova

Proceedings of the Zoological Institute RAS, 2022, 326(3): 164–171 · https://doi.org/10.31610/trudyzin/2022.326.3.164

Full text

Abstract

The article is devoted to determination of sex of juveniles of small mammals. The definition of which is the most time-consuming part of anatomical research. The method of visualizing the sex of young animals by reproductive organs using 3% hydrogen peroxide (H₂O₂) and 6% apple cider vinegar (CH₃COOH) is used. Earlier in 2020, this method was successfully used on immature shrews (Sorex). The results of the study served as an impetus for the continuation of the study on juveniles of the hamster family (Cricetidae Fischer, 1817) and repeated testing on young individuals of the shrew family (Soricidae Fischer, 1814). The collection of material was carried out in 2021 in the central part of the White Sea-Kuloy Plateau. A total of 475 small mammals from three families were studied (Cricetidae – 291, Soricidae – 183, birch mice Sminthidae Brandt, 1855 – 1). Anatomical examination of biological material showed that 24% (n = 114) of young animals turned out to have indeterminate sexual characteristics. These juvenile individuals belonged to the families of shrews (15.8%) and hamsters (8.2%). As a result of the method, gender differences were found in 92.1% of juvenile individuals. During the reaction of hydrogen peroxide with blood catalase, in 35.2% of males (of the identified individuals), the spermatic ducts were elevated, and in 51.4% of them, seminal ducts and testes were discolored. In 43.8% of females, the horns and the body of the uterus increased in size by 2 times, and it turned white in 48.6%. In 7.9% of specimens, the sex has not been set due to postmortem damage to internal organs. The study proves that the method of visualizing sex by reproductive organs is effective for immature animals of Cricetidae and Soricidae. The method makes it possible to reduce the number of unrecorded juveniles and to obtain reliable information about the sex and age structure of the population.

Key words

anatomical studies, uterus, visualization method, immature small mammals, hydrogen peroxide, sex, seminal ducts and testes, Cricetidae, Soricidae

Submitted June 17, 2022 · Accepted August 17, 2022 · Published September 25, 2022

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