How are oviparous, viviparous, and ovoviviparous different?
Oviparous refers to those animals who lay eggs; depositing eggs that develop and hatch outside the body as a reproductive strategyViviparous refers to Being born alive (without eggs), as are most mammals, some reptiles, and a few fish. In this system no eggs are laid.Ovoviviparous refers to such kind of animals whose eggs hatch inside their body, such as some reptiles & amphibians. The eggs hatch in the oviduct within the mother's body and that the egg's yolk and fluids secreted by glands in the walls of the oviduct nourishes the embryos.Most sharks are OvoviviparousImages: From Bing Search
Are guinea pigs oviparous, ovoviviparous, or viviparous?
Guinea pigs are viviparous, because when an animal is viviparous it means reproduction is in the body of the mother. Most mammals and reptiles are viviparous.
Is a seahorse viviparous, oviparous or oviviparous?
oviviparous--this means that the eggs are stored within the body rather than being laid on the ground (in the sea, etc.). It can be confusing because viviparous means that the embryo actually attaches via a placenta to the body of the parent/mother. In the case of seahorses, as you probably know the eggs are transferred to the male and he houses them, but the embryo never attaches to his body. Therefore just to reiterate--oviviparous
Compare the three reproductive strategies used by mammals?
i believe the three reproductive strategies used by mammals could only be these: 1. pregnatation, semen, egg, in the uterus, 20 ~ 500 days. fetus feed and breathe through umblical cord with mother inside the womb. and then, contraction of the uterus and.. baby. example: humans! 2. ovulate (laying eggs) semen, egg, lay on it and wait for hatching. feotus feed on egg yolk. These are real eggs with real shells. ?? days example: platypus! 3. semen, egg, pregnatation, BUT in an open womb. baby do not rely on mother but feed and breathe externally. No umbilical cord. and they cant really move during gestation example: kangaroo! No more other ways for now :)
Ovoviviparous?
Ovoviviparous is a zoological term that refers to animals that produce eggs but retain them inside the female body until hatching occurs, so that "live" offspring are born. The egg-hatching strategy of ovoviviparity occurs in a rather wide diversity of animals, including certain insects, fish, lizards, and snakes. However, ovoviviparity is much less common than the external development of fertilized eggs (that is, oviparity). Ovoviviparous insects do not provide oxygen or nourishment to their developing eggs; they merely provide a safe brooding chamber for development. However, species of ovoviviparous fish, lizards, and snakes appear to provide some nutrition and oxygen to their developing progeny within the oviduct (although most nutrition is provided by the yolk of the eggs). Moreover, in these species the eggshell is greatly reduced in thickness and is essentially reduced to a membrane. Because some nutrition is provided to the developing egg and larva and the eggshell is essentially absent, the cases of ovoviviparity in fish, lizards, and snakes are considered by some zoologists to represent true live birth, or viviparity. There are many cases of ovoviviparity, but only a few vertebrate cases will be used here to illustrate the syndrome. The guppy (Lebistes reticulatus) is a small, freshwater fish that is native to the West Indies and northern South America, and is commonly kept as a pet in aquaria. The guppy is internally fertilized, and the eggs are retained in the oviduct of the female where they hatch and develop, so that live young are born. Similarly, the garter snake (Thamnophis sirtalis) is a common and widespread species in North America. This species achieves internal fertilization by copulation, incubates the eggs within the oviduct of the female, and gives birth to live young in the late summer. At birth, the young snakes are enclosed in an amniotic sac from which they quickly escape and then slither away to lead an independent life.
How do sharks, manatees & whales have sex? I am NOT being funny I am trully curious.............?
I know some lay eggs but their reproductive organs on on their bellies right? What is the gestational periods? Details would be great. This baffles me. Please serious ansers only. Thanks
What are the advantages of oviparous animals?
Oviparous reproduction is the process of laying unfertilized eggs in an external environment. Such reproduction is shown by many species of snakes, lizards, etc.In contrast, viviparous reproduction is the process of giving birth to young ones. It is mostly seen in mammals.As it is evident, viviparous reproduction evolved from oviparous reproduction and, as we can oourselves see, has served man quite well. So the question that arises is why do some animals still reproduce oviparously?Well, since they do so there must be some advantage to it.Traditionally viviparous reproduction has been considered inherently superior to oviparous reproduction which is somewhat bias towards mammals and fails to consider the biological significance reproductive diversity. A more sophisticated approach would be to call them reproductive ‘strategies’ both of which have their own advantages and disadvantages. Some advantages of oviparous reproduction over viviparous are :In viviparous reproduction, during pregnancy, the feeding and locomotion of the mother is affected which subsequently effects maternal and offspring survival. There is no such risk in oviparous fertilization.Space constrains limit litter size more in viviparous forms than in the oviparous relatives because the wet mass and volume of neonates (new born mamals) exceeds that of the ovulated yolk.Furthermore, pregnancy may prevent a female from starting the next litter of offspring which effects the net reproductive output. This does not happen in oviparous reproduction.
Is a shark a fish or a mammal?
You are right, it is a FISH. A shark breathes through their gills like any other fish do. Shark is different from the Whale. Whales are large, magnificent, intelligent, aquatic mammals. They breathe air through blowhole(s) into lungs . I suggest that the whale shark is the cause of confusion. Don't get confused with a whale shark to think shark as a mammal because of the "whale" in its name. Whale shark is just a kind of shark considered as the biggest shark and the biggest fish. It is NOT a whale. You have to differentiate and specify 'Whale Shark' from a 'Whale'. Don't get confused if you see "Whale" before the 'Shark' ('Whale Shark').You see, you have to be careful when the name "whale is attached to the name." Just like the "Killer Whales" and "Pilot Whales", there is the name whale attached to their names yet they are not whales but dolphins but they are also mammals. Anyway just bear in mind that 'Whale Shark' is a fish and all the rest of combined names bearing 'whale' are mammals- either a real whale or dolphins. (Examples: Blue Whale, Killer Whale, Pilot Whale, Humpback Whale, etc.)♥
How big are shark eggs for different species of shark?
Surprisingly, this is not an easy question to answer. Shark reproduction is characterized by internal fertilization, k strategy (few rather than more), and direct development (no larval stage); but this is where the gross similarities end. Different species employ different reproductive strategies: viviparity, ovoviparity, and oviparity. Viviparous sharks give birth to live young. These develop inside the mother who provides additional nutrients to a meager yolk sac. These nutrients may be introduced by a placenta as well as fetal consumption of eggs and embryos (intrauterine cannibalism). The second two strategies are why this question is complicated. Thus far, the biggest egg recorded from a shark species was from the whale shark Rhincodon types. The egg was recorded to be 14inches. Whale sharks, however, are now known (or at least believed) to be ovoviviparous. This means that although eggs, yolk sac and all, are produced they are held within the mother. The eggs hatch inside and the mother gives birth to live young. The discovered egg is thought to have been aborted. So, thus far, the whale shark is considered to have the biggest egg; but should this count? I have not found information regarding the egg sizes of other shark species, nor do I know if the whale shark egg is considered biggest compared to body size or strictly in absolute terms.