During amplexus, the male frog wraps his hind legs around the female frog and holds her body with his front legs. Amplexus is a form of external fertilization as the fertilization of the eggs occurs outside of the animals' bodies. Amplexus is the pose assumed by amphibians during their mating ritual. Both genders of frogs contain their entire reproductive system within their own bodies. The cloaca opens to the exterior by a cloacal aperture at the posterior end of the frog's body. The ovisac opens the posterior end in the dorsal wall of the cloaca through its individual apertures lying anteriorly to the openings of ureters. The coiled oviduct travels posteriorly along the outer side of the kidney while the hinder portion of the oviduct becomes very thin walled. It then becomes highly coiled and thick-walled. The oviducal funnel is located on the dorsal side of the lung and also leads into the oviduct. 1.Oviducal Funnel 2.Oviduct 3.Ovisac The frontal end of the oviduct forms a wide oviducal funnel. Each oviduct is a long narrow, highly coiled tube and is divided into three parts in accordance with its structure as well as its functions. The ovarian follicles project towards the lumen of ovary and then the ovary enlarges. Each of the ovarian follicles contain a developing egg. During the breeding season, the wall of the ovary becomes studded having a large number of ovarian follicles. Just like the smaller frogs, each ovary in the female frog is small flat and lobulated throughout the year except during the breeding season. Also the fertilization process is external. During this time, it causes the female to release her eggs and then the male frog releases a layer of sperm onto the eggs through his cloaca. When frogs mate, the male climbs on top of the female, this certain position is called amplexus and can last several days. The cloaca is a small, median chamber that allows fecal matter, urine and sperm to pass out into the exterior. The urogenital duct emerges from the kidneys and then opens into the cloaca. Once in the kidneys, the vasa efferentia open into the bidder's canal and communicate with the urogenital duct.
There are around 10 – 12 vasa efferentia and once they arise from the testes, they travel through the mesorchium and enter the kidneys on their side.
The peritoneal funnels on the ventral face of the kidneys.The male frog's testes are found in the upper part of the kidneys near a double fold of peritoneum called mesorchium. Than that of the female and the absence of coelomic cilia except in The tympanum and the forearm a more slender and streamlined body Season approaches a distinct low, guttural croaking sound with theĪccompanying swelling by air of the lateral vocal sacs located between Pad which changes thickness and color intensity as the breeding The identifyingįeatures which distinguish it from the female are a darkened thumb The mature male frog is generally smaller than the female, rangingįrom 60 to 110 mm. The end result is the haploid gamete, in either instance. In many forms the first division is reductional and the second is equational. The oocyte and spermatozoa maturation process. Historic Disclaimer - information about historic embryology pages (1951) The Blakiston Company.įrog Development (1951): 1 Introduction | 2 Rana pipiens | 3 Reproductive System | 4 Fertilization | 5 Cleavage | 6 Blastulation | 7 Gastrulation | 8 Neurulation | 9 Early Embryo Changes | 10 Later Embryo or Larva | 11 Ectodermal Derivatives | 12 Endodermal Derivatives | 13 Mesodermal Derivatives | 14 Summary of Organ Appearance | 15 Glossary | 16 Bibliography | Figures Book - The Frog Its Reproduction and Development.
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