The Female Reproductive Cycle of the Neotropical SnakeAtractus pantostictus(Fernandes and Puorto, 1993) from South-eastern Brazil

Abstract

Data on reproductive activity of fossorial species are limited because the specimens are difficult to be observed and captured. Here in, we present the reproductive cycle of female Atractus pantostictus, a fossorial neotropical species, and the sexual maturity of males and females in south-eastern Brazil. The female reproductive cycle of A. pantostictus is seasonal, with vitellogenic follicles being found from September to April and eggs in November, February, March and April with the number varying between two and four. Spermatozoa were found in the lumen of the glandular and non-glandular uterus in females collected during the rainy season. Sperm storage tubules were found in the posterior infundibulum of the females, where the storage of sperm occurs for a short time. The storage may occur because mating and ovulation are dissociated.

Ecology of the snake Atractus paraguayensis (Dipsadidae) in southern Brazil

“…Male and female A. paraguayensis have different body sizes when they attain sexual maturity. This trend has been noted for the majority of snakes (Gomes and Marques 2012, Alencar and Nascimento 2014, Marques et al 2014, Resende and Nascimento 2015. However, females tend to be larger than males.…”

“…Larger species, such as A. major Boulenger, 1894 (723 mm) and A. torquatus (Duméril, Bibron & Duméril, 1854) (754 mm) produce similar postures Oliveira 1993, 1999) (6-12 and 7-8 eggs, respectively). Smaller species, such as A. pantostictus Fernandes & Puorto, 1993 (248 mm) (Resende and Nascimento 2015) and A. reticulatus (Boulenger, 1885) (335 mm) (Balestrin and Di-Bernardo 2005), exhibit small clutches (2-4 and 1-3 eggs, respectively). Larger females may produce larger or more offspring, or have higher reproduction frequencies (Shine 1988).…”

Sperm storage and morphofunctional bases of the female reproductive tract of the snake Philodryas patagoniensis from southeastern Brazil

“…The different oviductal regions described herein are also similar to other snakes regarding structure and function (Saint-Girons 1957;Bauman and Metter 1977;Mead et al 1981;Sever et al 2000;Siegel and Sever 2008a; . The epithelial cells secrete neutral carbohydrates and carboxylated glycosaminoglycans throughout the reproductive cycle (Gabe and Saint-Girons 1965;Uribe et al 1998;Sanchez-Martinez et al 2007;De Resende and Nascimento 2015). This constant secretory activity indicates that they act in the protection against invasive microorganisms, lubrification, and humidity maintenance avoiding the loss of water (Junqueira and Carneiro 2008).…”

“…Thus, the use of equivalent terms based solely on a visual comparison of macroscopical regions may be considered with caution (Blackburn 1998). Anatomically, the oviduct of P. patagoniensis showed similar characteristics to other Dipsadidae species (De Resende and Nascimento 2015). However, the scarcity of morphofunctional studies on the female reproductive tract, mainly considering neotropical species, makes difficult to compare and understand the appearance and evolution of structures within this lineage.…”

Uterine and eggshell modifications associated with the evolution of viviparity in South American water snakes (Helicopsspp.)

“…A similar staining pattern occurs in oviparous and viviparous females of reproductively bimodal lizards (Heulin et al., ; Stewart et al., ). However, it is noteworthy that the epithelium of the infundibulum (the oviductal region anterior to the uterus; Blackburn, ) of several squamates also stains for neutral carbohydrates and acidic mucosubstances (de Resende and Nascimento, ; Girling et al., ; Guillette et al., ; Siegel & Sever, ). Thus, neutral carbohydrates and acidic mucosubstances from the infundibular epithelium may also be incorporated to the inner boundary as the eggs enter the infundibulum at ovulation (Guillette et al., ; Stewart et al., ), as observed, for example, in the lizard Sceloporus woodi (Palmer et al., ).…”