ABSTRACT
The male reproductive system in lizards consists of the gonads (testis), gonadoducts (testicular ducts), the sexual segment of the kidney (SSK), and the cloaca (Rheubert et al. 2010). In lizards, sperm develop in the germinal epithelium of the seminiferous tubules within the testis (Gribbins 2011) and pass sequentially through the various portions of the gonadoducts; rete testis, ductuli efferentes, epididymis, ductus deferens, and, in some species, an ampulla ductus deferentis (Figs. 9.1 and 9.2; Sever 2010). Sperm then usually mix with secretions from the SSK in a variable ductus deferensureter complex, and enter the cloaca through the urogenital papillae (Figs. 9.1 and 9.2). Each of these regions is controlled by hormone fl uxes that vary throughout the reproductive and non-reproductive seasons subject to seasonality and, thus, undergo morphological (and physiological) changes throughout an entire calendar year (Prasad and Sanyal 1969; Jones 2002). This seasonality refl ects the function of the various portions of the male
1 College of Sciences, The University of Findlay, Findlay, Ohio, 45840 USA. 2 Department of Biology, Southeastern Louisiana University, Hammond, Louisiana 70402,
USA. 3 Department of Biology, Southeast Missouri State University, Cape Girardeau, Missouri, USA. 4 Department of Biology, Arkansas State University, Jonesboro, Arkansas, USA. *Corresponding author
reproductive system and will thus be discussed in more detail later in this chapter. This chapter will focus on these various regions giving a historical, morphological, ultrastructural, and comparative view. Although the gonadoducts begin intratesticularly, morphological descriptions of the testis are discussed in detail in Gribbins and Rheubert Chapter 11, this volume.
