Do reptiles have a larval stage?
Reptiles do not have a larval phase and do not go through metamorphosis. While most reptiles lay eggs, a few species of reptiles give live birth. Reptiles are covered with dry scales rather than the semi-permeable skin of amphibians.
Do lizards have Cervixes?
Reptiles are almost all sexually dimorphic, and exhibit internal fertilization through the cloaca. Some reptiles lay eggs while others are ovoviviparous (animals that deliver live young). Reproductive organs are found within the cloaca of reptiles.
Do female lizards have a uterus?
Females have paired ovaries and oviducts, which enter into the urodeum of the cloaca. The oviduct is divided into four regions: infundibulum; magnus (secretes albumin); uterus (secretes membrane); and vagina.
Do snakes have placentas?
In viviparous lizards and snakes, embryos develop inside the pregnant female and are sustained by placental organs. Our research focuses on functional morphology and evolution of these placentas.
Do snakes get pregnant?
It all starts with a mature female getting pregnant from a male of the same species. Once pregnant, there are three basic ways snakes are born. The first is for an egg to develop inside the mother. Then the egg is deposited, usually in a group, in a specific habitat to hatch.
Do reptiles ovulate?
In reptiles copulation may stimulate ovulation, occur simultaneously with ovulation, take place within an hour to a week of ovulation (presumably the most frequent situation), or occur months prior to complete the development of the eggs and their ovulation.
Do eggs have placentas?
Indeed, the uterus (not the placenta) is the organ in which mammals carry their fertilized eggs; the placenta is the source of nourishment for these internally carried young in most mammals. Furthermore, there are mammals which lay eggs and have no placenta.
How is the uterus of a squamate different from a crocodilian?
The uterus of squamate and testudine reptiles is a single structure in which protein secretion and formation of the calcareous portion of the eggshell are separated in time, whereas in crocodilians the protein and calcareous components are produced in different regions of the uterus (Palmer et al., 1993).
How does a whiptail lizard reproduce without fertilization?
These reptiles reproduce by parthenogenesis. In this process, eggs undergo a chromosome doubling after meiosis, developing into lizards without being fertilized. However, ovulation is enhanced by female-female courtship and “mating” (pseudo-copulation) rituals that resemble the behavior of closely related species that reproduce sexually.
What kind of animal does a reptile feed on?
Join Britannica’s Publishing Partner Program and our community of experts to gain a global audience for your work! With few exceptions, modern reptiles feed on some form of animal life (such as insects, mollusks, birds, frogs, mammals, fishes, or even other reptiles).
How are reptiles able to survive in water?
Many are aquatic, living in both fresh water and the sea. The skin of reptiles is covered in impermeable scales and they are able to retain water very effectively. Their eggs are covered by a hard shell, providing a sealed environment for the developing embryo, which does not depend on external sources of water.
How are reptiles important in the environment?
Reptiles are important components of the food webs in most ecosystems. They fill a critical role both as predator and prey species. Reptile species can also have a useful anthropogenic role in ecosystems. In some areas, they help control the numbers of serious agricultural pests by consuming rodent and insect pests.
