Animals that give birth to live young, called viviparous, include most mammals (humans, dogs, cats, whales), many fish (sharks, guppies), some reptiles (certain snakes, lizards), amphibians (some caecilians), and invertebrates (some cockroaches, aphids). This reproductive strategy allows internal development, protecting embryos from external environments, and has evolved independently in many different animal groups, from sharks to snakes to whales.
Here are 10 animals that hatch from eggs and also give birth to live young:
Backward-aging jellyfish
At the top of our immortal animals list is a tiny variety of jellyfish known as Turritopsis doohmii, or more commonly, the immortal jellyfish. It has found a way to cheat death by actually reversing its aging process, according to National Geographic.
Mammals: Most mammals, including humans, dogs, cats, elephants, whales, and many more, give live birth. Some Reptiles: While most reptiles lay eggs, some, certain species of snakes and lizards, give birth to live young. Some Fish: Certain species of sharks and rays give birth to live young instead of laying eggs.
Did you know the longest brooding period or 'pregnancy' of any known animal is a whopping four and a half years? If you think female African elephants have it tough with their 22-month gestation period, spare a thought for the deep-sea octopus Graneledone boreopacifica.
Aphids, tiny insects found the world over, are “essentially born pregnant,” says Ed Spevak, curator of invertebrates at the St. Louis Zoo.
Parthenogenesis occurs naturally in aphids, Daphnia, rotifers, nematodes, and some other invertebrates, as well as in many plants. Among vertebrates, strict parthenogenesis is only known to occur in lizards, snakes, birds, and sharks.
Copperheads are ovoviviparous, meaning they give birth to their young encased in an amniotic sac, rather than laying eggs like many other snakes. After giving birth, a copperhead mother does not care for her young.
7 uncommon animals that produce milk
The Amur leopard is one of the rarest big cats in the world, with only around 100 individuals left in the wild.
Jellyfish and comb jellies
This cycle can repeat indefinitely, potentially rendering it biologically immortal. These organisms originated in the Caribbean Sea, but have now spread around the world.
A "silent killer" animal can refer to predators known for stealth like leopards, owls, or snakes (like the Common Krait), but also to seemingly harmless creatures like the venomous slow loris (a mammal) or even the disease-carrying mosquitoes, highlighting threats that are quiet, unassuming, or invisible, from stealth hunters to disease vectors.
Like humans and all mammals, cats are born live. They don't hatch from eggs like birds and reptiles. A baby cat is called a kitten. For the first 4-6 weeks of a kitten's life, it can't eat any normal food - it just drinks its mother's milk, so it has to be around her all the time.
Share: Elephants have the longest pregnancy period of any living mammal. If you – or someone you know – has experienced a pregnancy that seemed to go on forever, spare a thought for the elephant. It's the animal with one of the longest gestation periods of all living mammals: nearly two years.
The answer to this question is heavily debated by scientists. Dozens of different studies using everything from chromosome evolution over time to ancient fossils have boiled it down to two candidates: sponges and comb jellies.
Telling male and female snakes apart is not always easy. There is no general rule that applies to all species. In adders of the genus Bitis, the females have much shorter tails than the males – but without another tail to compare with, it could be confusing.
FWC: We do not recommend anyone destroy a nest of eggs unless a female python is clearly circled around the nest of eggs.
The viviparous lizard or common lizard (Zootoca vivipara) is a Eurasian lizard. It lives farther north than any other non-marine reptile species, and is named for the fact that it is viviparous, meaning it gives birth to live young (although they will sometimes lay eggs normally).
Swamp wallabies are always pregnant, can conceive again before giving birth | National Geographic.
''Virgin births'' in crocodiles may be common, say the researchers. The first case of a crocodile who made herself pregnant has been identified at a zoo in Costa Rica.
As the eggs begin to develop immediately after ovulation, an adult female can house developing female nymphs which already have parthenogenetically developing embryos inside them (i.e. they are born pregnant). This telescoping of generations enables aphids to increase in number with great rapidity.
Watch for signs that bull sea lions are territorial, they will bark, blow bubbles, and show you their teeth when they are warning you to back away. Do not ignore these signs, they mean business.
Elephant. The majestic elephant holds the record for the longest gestational period among land mammals, with pregnancies lasting approximately 22 months.
1. Hyenas. Hyenas are often depicted as dirty, ugly scavengers, yet in the wild, they are the biggest threat to lions. These two species engage in fierce competition over food sources, leading to epic confrontations.