Reptiles are members of the Reptilia class and are popular for crawling on their bellies.
Living reptiles include turtles, crocodiles, snakes, etc.
However, a popular question about reptiles is, “How do reptiles reproduce?”
Reptiles are of sizes and shapes, from tiny lizards to giant dinosaurs. Though their reproductive methods differ from those of mammals, there are some similarities.
Even among reptiles, there can be big differences in how they reproduce.
Some reptiles don’t lay eggs like birds but give birth to live babies. Even some female reptiles don’t need males to have babies.
Read on as I discuss reptiles’ method of reproduction extensively.
Courtship
The female and the male reptiles need to cooperate to have sex. In most reptiles, the male performs a series of courtship behaviors to see if she is willing to have sex with him.
Many lizards do head bobs and forearm push-ups in the same way. Male crocodiles use body movements, water vibrations, and sprays to attract females and scare away males.
Chameleons change their colors to attract a mate. Male turtles often moved their heads up and down to get a female partner. Also, they gather in groups of up to 30,000 snakes for a mating ball.
Other male reptiles fight to show who is in charge and have sex with the females. Monitor lizards try to push each other down with their hind legs and tails on the ground.
Male tortoises always fight with their heads and bodies when there are other turtles around, and the goal is to push the other male away.
Further, reptiles release pheromones, chemical smells that make them want sex with female reptiles.
Sex Differentiation
External genitalia is absent in male and female reptiles, making it difficult for owners to discern their gender. Males and females, however, have separate reproductive organs. The testicles of a male reptile are within its body.
Males have either a single penis or two hemipenes, which are visible on the outside as two bulges behind the cloaca towards the animal’s tail. Male genitalia is separate from the urinary tract and is only used for reproduction.
Also, we can use secondary sexual features such as size and color to differentiate them.
The plastron of male chelonians is concave, and the tail is longer. Male reptiles’ heads and bodies are larger than female reptiles’. The male Jackson’s chameleon has three noticeable horns on his head, while the female lacks them.
Male iguanids and geckos have femoral or pre-anal pores that exude a waxy material. Thus making them more visible than females. Spurs on either side of the vent are present in many boas and pythons, which are greater in males.
Further, male reptiles’ tails are generally longer than females’. Ultrasound and radiography are other methods for determining reptiles’ sex.
Reproduction
Although certain reptiles can reproduce asexually, most reproduce sexually. Males have one or two penises, which transfer sperm from their cloaca to a female’s cloaca. Most reptiles are oviparous, laying eggs outside the female’s body.
However, several snakes and lizards are ovoviviparous, giving birth to live offspring. Their eggs are kept within the female’s body and hatch there.
The young animal emerges from the female, alive and covered in embryonic fluid, much like mammals.
Fertilized eggs come out of the female’s body through the cloaca hole. Only eggs of a few species stay inside the female’s body until they hatch.
Then, the progeny comes out of the mother’s body through the cloaca hole.
Fertilization
A male reptile fertilizes a female by inserting either his single penis or two hemipenes into her cloaca. As mentioned earlier, the couple engages in courtship before actually copulating, and it can preserve sperm for up to 6 years after copulation.
This sperm can be used to fertilize succeeding eggs without more male contact.
For instance, the healthy adult female green iguana can start growing eggs even if no male is available to fertilize the eggs.
The process begins with the ovaries, which stay inside the body and store eggs. Most female green iguanas reach sexual maturity between two and four.
Follicles begin to form in the ovaries. Each follicle consists of a small egg and a yolk-filled sac. The follicles then detach and travel into the oviducts, where the egg white is added, and a shell around the yolk and white is placed.
Amniotic Eggs
Amniotic eggs are in reptiles, birds, and mammals. Because amphibian eggs lack an amnion and would dry up if put on land, amphibians prefer to lay their eggs in water.
Amniotic eggs include albumin, which provides water and protein to the embryo, and egg yolk, which offers energy to the embryo.
Only amniotic eggs have the chorion, amnion, and allantois membranes. The chorion helps the embryo and its environment exchange gases.
Care for the Young Reptiles
There is no larval stage in reptiles. Instead, newly hatched reptiles resemble adult reptiles in size. They can travel around independently, but they are vulnerable to predators.
Despite this, most reptile parents neglect their hatchlings.
However, some reptiles usually conceal them in a hollow log or a hole in the ground to save them from predators. For instance, snakes guard their young by wrapping their tails around the eggs.
Alligators transport their infants to the water by placing them in their mouths.
Furthermore, the number of eggs laid by a reptile varies between species.
