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Top 10 Things You Didn’t Know About Animal Reproduction

Nature has come up with many weird and wonderful ways of swapping genes.

Top 10 Things You Didn’t Know About Animal Reproduction

1. World without males

Reproduction costs a lot of energy, so why not evolve to bypass it altogether? Well, one group of animals has. Bdelloid rotifers (the ‘b’ is silent) are tiny creatures found in bird baths, ponds and puddles. When wet they come to life and hoover up micro-organisms. When conditions become dry again they shrivel up into a ball and are blown from place to place. There are billions of them on Earth, and every single one is female. Without mixing up their genes through reproduction with males in perhaps 40 million years. The rotifers should fall prey to bacteria and viruses, their defences outmanoeuvred. Yet they are still here. How? It seems that drying up then blowing from place to place may allow them to outflank and outlast their parasites. In their world, males add no genetic value.

2. Pandas are good at it

Pandas

Giant pandas are widely chastised for being unable to ‘get in the mood’ in captivity, and for having
a window of ovulation (about 36–48 hours) too tiny to be practical. The reproductive life
of Edinburgh Zoo’s Tian Tian and Yang Guang shows just how difficult it can be to encourage the species to breed normally in captivity. But in the wild, pandas are masters of reproduction. Even though their territories can be enormous, males and females locate one another at exactly the right time for ovulation, primarily by monitoring chemical messages left on trees via squirts of urine.

They also communicate vocally. Males bleat when they approach a reproductive female, possibly offering
an opportunity for her to assess his size and strength. A female in oestrus often mates with several males, so they have evolved one of the highest sperm counts of all bears, to better guarantee any offspring is theirs. As our understanding of the animal’s wild breeding improves, zoos adapt accordingly.

3. Girls who are boys

Girls who are boys

Many animals, especially fish, switch between egg-producing (female) and sperm-producing (male) phases during their lives. For instance, in many reef fish all of the juveniles are females and become males as they grow. These are known as ‘sequential hermaphrodites’, a phenomenon very common across a number of taxonomic groups.

In invertebrates, particularly slugs and snails, things go a step further – individuals possess male and female genitalia at the same time. In fact many slugs and snails even have the ability to fertilise their own eggs. With such flexible reproductive equipment, it’s no surprise that a number of invasive species are hermaphroditic. Among the most worrying is the Spanish slug, which has become a serious agricultural pest across much of Europe. A single egg transported in a flowerpot is all it takes to unleash this master and mistress into new places.

4. Reproduction on the moon

Reproduction on the moon

The diversity of mites’ sexual behaviour is staggering. There are mate guarders, harem keepers, warring males, macho show-offs, incest and cannibalism. Perhaps the most celebrated of all is the red velvet mite. Males create trails of silk in their territories that direct females to little packages of their sperm, called spermatophores. If one approves, she will absorb the sperm into her body. Species of mite are everywhere – in the noses of seals, on the legs of chickens, in the ears of porcupines, in the middle of a sea urchin and within the rectums of bats. In fact it’s likely that eyelash mites are reproducing on your face right now. It’s probably the only animal to have reproduced on the moon, carried by the 12 men who have

5. Singing genitalia

 micronecta_scholtzi

The variety of male genitalia in the animal kingdom is jaw-dropping. There are fin-like ones (sharks), barbed ones (cats, beetles and dragonflies), regenerative ones (seaslugs), lobes (turtles), hooks (mosquitofish), fingerlike extensions (barnacles) and a detachable swimming apendage (the Argonaut octopus). Some have become adapted for other sexual purposes. The lesser water boatman (right) frantically rubs its genitals against a special comb-like structure on its body to pump out a mating call equivalent to almost 100dB. Relative to size, it’s the loudest animal on Earth.

6. The value of DIY

lizad

One of the greatest mysteries is why so many animals seek to pleasure themselves, rather than find reproductive opportunities with others. Lions, bats, walruses, warthogs, whales, dolphins and deer are just some of those known to partake in such ‘auto-eroticism’. Are such behaviours evolved, or are they emergent phenomena associated with something else, such as captivity? The marine iguana is one species where auto-eroticism is common – smaller males rub themselves against rocks as they approach reproductive females. The behaviour means that their resultant copulations are shorter, so smaller males are less likely to be interrupted by bigger, burlier rivals. According to research, the strategy is likely to increase their chances of a successful mating by 41 per cent – easily enough to be evolutionarily significant.

7.Monogamy is hard to find

Monogamy birds

Monogamy rarely flourishes in animal groups because fidelity limits an individual’s reproductive potential. It only persists among the species where the result is a higher number of healthy offspring. In birds, where the raising of chicks may demand care from both parents, monogamy arises fairly frequently. But it has popped up in other species and groups, too: antelopes, prairie voles, some cichlid fishes and the Australian sleepy lizard (also known as the shingleback skink). None of these are true monogamists though – each may be inclined to change partners between seasons.

Though many consider swans, albatrosses and emperor penguins to be nature’s most virtuous couples, all of these pale in significance compared with Eurasian bullfinches and jackdaws. Bullfinches are highly monogamous, and as a result males are modestly endowed and produce poorquality sperm, not having any need for more sophisticated reproductive mechanisms. On the other hand, jackdaws remain faithful for life and stay near their partners year-round, even within bustling and complex colonies. They are perhaps the most monogamous of all common birds.

8. Mutual attraction

Mutual attraction

Though animals rarely eschew reproduction totally with the opposite species, hyenas, lions, whiptail lizards, dragonflies and bed bugs through to orcas, koalas, barn owls, king penguins, mallards, sticklebacks and rattlesnakes, to name but a few, do exhibit such tendencies. According to the experts, bottlenose dolphins indulge in them as much as heterosexual activities. Only in recent years have scientists begun to lift the lid on the evolutionary causes that may be responsible. Though such animals in vertebrates obviously suffer from lower reproductive outputs, there may be evolutionary benefits such as kin selection, whereby non-reproductive offspring enhance the survival and reproductive chances of their siblings, ensuring their own family genes persist.

9. Duck dramas

Duck dramas

Being largely internalised soft structures, female genitalia can be tricky to study. Among the best understood are ducks’. Intense competition between male ducks has done remarkable things. They have evolved one that can be ‘exploded’ into a female’s reproductive tract, giving a male a greater chance than his rivals of successful fertilisation. In response the female reproductive tract has evolved into an anticorkscrew, with pockets and dead ends. By modelling the tract of Muscovy ducks, scientists found that she can rebuff unwanted sperm – her reproductive passages only loosen enough to grant access to the males that she deems worthy. They’re the ones with the brightest bill, for those are most likely healthiest and less likely to be infected with diseases.

10. Fatal attractions

Fatal attractions

Episodes of reproduction that are so intense the animal dies, known as semelparity, evolve when it pays more (in terms of offspring) for males and females to invest everything in one act than to stay alive and breed again next year. The Pacific salmon is a good example. Though not strictly semelparous, frogs and toads often live their last days during the breeding season. The energetics of mating are arguably worse for females than males – competition can be so intense that she drowns under a mass of rival suitors. But when this happens in the frog Rhinella proboscidea, death doesn’t spell the end – the males practise ‘functional necrophilia’, squeezing eggs from dead females which they fertilise in the water.

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Animal

Top 10 Surprising Facts About Sharks

Many people consider sharks as predators that may attack at any time, divers possess a different viewpoint. We find these animals that are diverse ancient and lovely entrancing, also it appears like there something new to find out about sharks.

 sharks-orig

1. Sharks normally have about 45 to 50 teeth but that’s just the front row teeth. Additionally they have, on the other side of the leading row typically, up to seven replacement rows of teeth ready to move into place if a tooth is damaged or falls out. With the activity a shark’s mouth sees throughout its life, an individual might go through as many as 30,000 teeth.

2. Even though we associate sharks with big, sharp chompers, some species barely need their teeth. Basking sharks and whale sharks, two of the largest species, are both filter have numerous, tiny teeth – a whale shark may have up to 300 lines of teeth and feeders.

3. While sharks don’t use sounds to communicate, they do rely on body language. If you’re snorkeling or diving, it’s good to be aware of the body language sharks use to communicate that they’re uneasy. Hunched backs, lowered pectoral fins, sharp movements (in zig-zag or back-and-forth patterns), and diving down to touch the bottom are all good indicators that a shark is feeling uncomfortable.

4. Some big sharks have dramatically longer life-spans than small sharks. For instance, whale sharks (which normally range from 18 to 32 feet/5.5 to 10 meters in length) can live up to 100 years, while the smooth dogfish (with a typical length between 2 and 4-feet/0.6 and 1.2 meters) might just live for 16 years.

5. Whale sharks claim the title of largest shark species, and are also the largest species of fish in the world. The basking shark, the second largest shark (and fish), averages between approximately 22 and 29 feet/ 7 and 9 meters. Pygmy Ribbontail Catsharks are perhaps the smallest, at about 6 to 7 inches/ 17 to 18 centimeters . Other small species include the Dwarf Lanternfish and the Spined Pygmy Shark , both of which are roughly the same average size as Pygmy Ribbontail Catsharks.

6. Sharks have of giving birth to their own young, complicated and diverse ways. Some lay egg cases, which have been nicknamed “mermaid’s purses” and sometimes wash up on beaches. However, live birth is given by a lot of sharks, along with a female might give birth to as several as 48 puppies in one litter.

7. There are some estimates that for each person people yearly kill 25 million sharks. There are 201 sharks on the “Red List” of endangered species, published by by the International Union for Conservation of Nature (IUCN). While estimates vary as to how many sharks are killed, either for harvesting fins, hunting or in incidental “bycatch” in fishing equipment, the figures are all dramatic, ranging from 70 to 100 million. Sharks are an essential component in marine environments, and their fast dwindling numbers are a main source of concern among conservationists. Movements like Project AWARE are bringing attention to and fight the over exploitation of sharks.

8. Research has helped break the myth that sharks are attracted to the color yellowish – in fact, they probably can’t see colour at all. The old saying “yum yum yellow” was rooted in the idea that sharks could see and were more likely to approach divers wearing the color. Because sharks’ eyes were found to lack or have minimal color-sensing cells , it seems to make more sense that what actually draws attention is the contrast in colors, rather than the color itself.

9. Sharks live in all seven of the world oceans, but they’re maybe not limited exclusively to wide-open bodies of salt water. There are species that can survive in mixed salt- and freshwater environments like estuaries and watersheds that connect to an ocean, while other species can live in completely fresh water. Bull sharks can survive in both saltwater and freshwater, and have been known to frequent the river.

10. Sharks are a living link with the period of the dinosaurs. Scales and teeth dating from more than 400 thousand years past offer hints about how those early ancestors appeared to us. However, what we consider as “ sharks that were modern appeared around 100 million years ago. The frilled shark, which can be uncommon but still in being, has developed almost no over the millennia and is regarded as one of the finest examples of what sharks that were early appeared to be.

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Animal

Top 10 biggest snakes in the world

10. Diamondback Rattlesnake

Diamondback Rattlesnake

Average length of Diamondback Rattlesnake  3.9 feet (1.1 meter)
Maximum length of Diamondback Rattlesnake  6.99 feet (2.1 meter)

Adults commonly grow to 120 cm (3.9 ft) in length. The maximum reported length considered to be reputable is 213 cm (6.99 feet) (Klauber, 1972). Even though this variation in dimension will not happen until they’ve reached maturity, Males become much bigger than females.

9. Giant Brown Snake

Giant Brown Snake

Average length of Giant Brown Snake  4.9 feet (1.5 meter)
Maximum length of Giant Brown Snake  9.8 feet (3 meter)

Giant Brown snakes growing up to 2.5 to 3.0 m (8.2 to 9.8 feet) in length in the largest specimens, although 1.5 m (4.9 ft) is a more typical length for an average adult. The brown snake is known as Dangerous to man. Bites from this species of snake have caused death within minutes, rather than hours or days, with even  a juvenile (newborn) potentially delivering enough venom in one bite – to kill 20 adults.

8. Bushmaster

Bushmaster

Average length of Bushmaster  6.5–8.25 feet (2–2.5 meter)
Maximum length of Bushmaster  12 feet (3.65 meter)

Adults Grown-ups vary in size from 2 to 2.5 m (6.5 to 8.25 ft), although some may grow to as much as 3 m (10 ft). The largest known specimen was just under 3.65 m (12 feet ), making it the longest venomous snake in the Western Hemisphere. This is also the longest viper, though not the heaviest (it is surpassed by the gaboon viper and the Eastern diamondback rattlesnake). The bushmaster’s tail ends with a horny spine which it occasionally vibrates when disturbed in a similar manner to rattlesnakes.

7. Diamond Python

 Diamond Python

Average length of Diamondback Rattlesnake  6.6 feet (2 meter)
Maximum length of Diamondback Rattlesnake  13 feet (4 meter)

It is a medium to large snake, found in coastal areas and adjacent ranges of south-eastern Australia. They can be the most southerly happening python in the world and are also found at higher altitudes than any other species of Australian python.

6. Boa Constrictor

Boa Constrictor

Average length of Boa Constrictor  3–10 feet (1–3 meter)
Maximum length of Boa Constrictor  14 feet (4.2 meter)

The Boa constrictor is a large snake, although only modestly sized compared to other large snakes like the Burmese and Reticulated python and can reach lengths of anywhere from 1–3 meters (3–10 feet) depending on the locality and the availability of suitable prey. There is clear sexual dimorphism seen in the species, with females generally being larger in both length and girth than males.

5. Black Mamba

Black Mamba

Average length of Black Mamba  8 feet (2.4 meter)
Maximum length of Black Mamba  14 feet (4.25 meter)

Black mambas have coffin-shaped heads and are lithe, athletic snakes. Based on National Geographic, they can grow to be 14 feet long (4.25 meters), although their average length is approximately 8 feet (2.4 m). These snake can live up to 1 1 years in the wild.

4. King Cobra

King Cobra

Average length of King Cobra  9.8–13 feet (3–4 meter)
Maximum length of King Cobra  18.8 feet (5.7 meter)

The king cobra is the world’s  longest venomous snake, having a length up to 18.5 to 18.8 ft (5.6 to 5.7 m). This snakes, which feeds primarily on other snakes, is found mostly in forests from India through South East Asia to the Philippines and also Indonesia.

The king cobra averages at 3 to 4 m (9.8 to 13 ft) in length and generally weighs about 6 kg (13 lb). The longest known specimen was kept captive at the London Zoo, and grew to around 18.5 to 18.8 ft (5.6 to 5.7 m).

3. Indian Python

Indian Python

Average length of Indian Python  7.9–9.8 feet (2.43 meter)
Maximum length of Indian Python  21 feet (6.4 meter)

The color pattern is whitish or yellowish with the blotched patterns varying from shades of tan to dark brown. This varies with habitat and terrain. Specimens in the hill forests of Assam and Western Ghats are darker, while these from the Deccan Plateau and East Coast are generally lighter.

In Pakistan, Indian Pythons commonly reach a length of 2.4–3 metres (7.9–9.8 feet). In Indian, the nominate subspecies grows to 3 metres (9.8 ft) on average. This value is supported with a 1990 study in Keoladeo National Park, where the largest 25% of the python people was 2.7–3.3 metres (8.9–11 foot) long. It can grow to a length of about 21 feet (6.4 m)

2. Green Anaconda

Green Anaconda

Average length of Green Anaconda  1517 feet (4.55.1 meter)
Maximum length of Green Anaconda  28 feet (8.5 meter)

The Green Anaconda is reputed to be the 2nd biggest snake in the world. It is a semi-aquatic boa that lives in the marshlands of South America. The common adult size to get a green anaconda is 15-17 feet; its weight can easily surpass 200 lbs, (the heftiest one found was 550 lbs). The largest to be confirmed is about 28 ft.

See also: Top 10 Most Amazing Colorful Snakes

1. Reticulated Python

Reticulated Python

Average length of Reticulated Python  1018 feet (3.6–5.4 meter)
Maximum length of Reticulated Python  32 feet (9.7 meter)

The reticulated python is found in South East Asia. Adults can grow to over 8.7 m (28 feet) in length but normally grow to an average of 3-6 m (10–20 feet). They’re the world snakes and longest reptile, but aren’t the most heavily built. Like all pythons, they’re nonvenomous constrictors and usually not considered harmful to individuals. The longest one was recorded to be 32 feet. The reticulated python is biggest snakes in the world.

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Animal

Top 10 Ugliest Animals in the World

Animals come in all shapes, sizes and colors. Some are beautiful, majestic and endearing. Others are downright nasty and repugnant. Wouldn’t it be fun to try and narrow down the worst looking of the bunch? Here is my unofficial list of the top ten ugliest animals in the world.

10. Sphynx Cat

Sphynx Cat

This cat is hairless and hideous. Despite its horrible looks, it is known as quite loving towards its human owners. They are also said to have fantastic personalities.

9. Warthog

Warthog

Found in Africa, the warthog looks like a pig with horns. Warts cover their large flat heads.   Even though these warts are for protection, they are not aesthetically pleasing to the eye.

8. Baird Tapir

Baird Tapir

The baird tapir is the largest mammal found in Mexico and South America. As if a nose and upper lip that stick straight into the air isn’t ugly enough, they also have four toes on the front feet and three toes on the back.

7. Proboscis Monkey

Proboscis Monkey

The proboscis monkey is on the endangered species list. Their long, protruding noses are used to honk in a form of communication with other monkeys.

6. Celestial Eyed Gold Fish

Celestial Eyed Gold Fish

Goldfish remind us of a small, cute pet fish. This is hardly the case with the celestial eyed gold fish. With eyes larger than their stomachs, they can be quite frightening.

5. Aye-Aye

Aye-Aye

Found in Madagascar, this is the largest nocturnal primate.   It taps on trees to find food, similar to the woodpecker. The aye-aye is on the endangered species list because it is thought to be bad luck and killed on sight.

4. Star Nosed Mole

Star Nosed Mole

The star nosed mole is located in parts of the United States and Canada. It has a star shaped nose with 22 fleshy tentacles reaching out. This absurd nose is so sensitive, it can even sense electricity.

3. Tarsier

Tarsier

As the smallest known primate, the tarsier is the size of a human hand. They like to jump from tree to tree to catch flying birds. If captured, this animal is known to kill itself due to the stress.

2. Naked Mole Rat

Naked Mole Rat

Also known as “sand puppy,” the naked mole rat is found in East Africa. They have large protruding teeth used for digging. The naked mole rats eyes are small and narrow, perfect for its life underground.

1. Blobfish

Blobfish

Found in the deep waters of Australia, the blob fish is the ugliest known animal in the world. It is rarely seen by humans because it lives in the deepest parts of the ocean. Due to its body make up, the blob fish can float above the sea floor without wasting any energy.

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