Features of topography and macroscopic structure of the digestive organs of the Yemeni chameleon (Chamaeleo calyptratus).

The relevance of this study is conditioned by the lack of detailed information on the structure and topography of the digestive organs of the Yemeni chameleon (Chamaeleo calyptratus). The purpose of this study was to find out the specific features of changes in body weight, topography, and structure of the digestive organs of the Yemeni chameleon, to determine their morphometric parameters in animals from 1 day to 1 year of age. The research material included the tongue, oesophagus, stomach, intestines, liver, and pancreas of chameleons of different sexes of 9 age groups. The data obtained were processed by one-factor analysis of variance (ANOVA). According to the topography, macroscopic structure and surface of the mucous membrane, there are three intestines in the small intestine: duodenum, jejunum, and ileum, and two intestines in the large intestine: the colon with a diverticulum and the rectum, which passes into the cloaca. A feature of the serous membrane of the chameleon intestine is that it is coloured black by melanin. From 1 day to 1 year of age, the body weight of chameleons increased 185.9 times, the snout-vent length (SVL) increased 6.7 times, the length of the digestive tract increased 3.8 times, and the ratio of the length of the digestive tract to SVL decreased from 3.2 to 1.8 times. The most intensive increase in body weight and SVL occurred during the second and third months of life. The relative length of the small intestine in chameleons of different age groups was 65.1-81.6%, with the longest part being the jejunum. The increase in the morphometric parameters of the stomach, intestines, liver, and pancreas was asynchronous. The most pronounced changes in their relative weight were determined in animals of 2-3 months of age. The obtained materials supplement and clarify the information on the topography and structure of the digestive organs of the Yemeni chameleon, and therefore they will be useful in X-ray and ultrasound examination during veterinary manipulations. [ABSTRACT FROM AUTHOR]