Tiny Sperm

Mice have sperm that is twice as long as elephants’. The world’s longest sperm belongs to a fruit fly. And across the animal kingdom, sperm take on extremely odd and varied shapes and sizes. The tadpole shape we most associate with sperm is not at all common outside of mammals. Rat and mice sperm can have hook-like attachments on their heads.

Some species seem to allow sperm to connect by their heads and form so-called sperm trains, these groups of sperm seem to swim faster than individual sperm.

From an evolutionary perspective this raises an intriguing question: Why are sperm so varied among different species when they all have the exact same purpose — fertilizing eggs? It turns out, the larger the species, the smaller the sperm.

Why would evolution favour such a pattern? When in comes to sperm, size matters. Longer sperm has some advantages — they are better at elbowing aside the competition. But it also takes a lot of energy to make long sperm, which larger animals can’t afford. So it’s a trade-off:

If there were no constraints on sperm production and assuming that longer sperm are advantageous, each male would probably produce lots of impressively big sperm. But in nature there are always constraints because resources and energy are not unlimited. For a testis of a given size, producing bigger sperm thus means it cannot produce as many of them (producing big sperm takes more resources, energy and time).

So, whether investing more in sperm size or in sperm number to maximize sperm competitiveness really depends on the circumstances, for example the size of the female reproductive tract. In large species, the female reproductive tract is massive compared to the tiny sperm, so sperm can easily be lost or diluted in it. Males have to compensate by transferring more sperm. Simply making longer sperm really would not make a difference in an elephant. They would have to be incredibly large. So males are better off making lots of tiny sperm.

This inverse correlation between animal size and sperm size might be a consistent pattern across the animal kingdom. Almost all animals with sperm longer than a 10th of a millimetre, he explains, weigh less than one or two pounds.

The mammal with the longest sperm? It’s not the human. That distinction belongs to the honey possum, a very small (they grow to 3.5 inches long ) marsupial that lives in western Australia. They are adorable. Their sperm is 350 micrometers (.014 inches) long.

Curious Ovum

The ovum, a mature egg cell released by the ovaries of the fertile female approximately every 28 days, is the largest human cell; whereas sperm, incidentally, is the smallest.

For conception to take place, a mature egg cell must be at the right place at the right time. Conception takes place when a sperm penetrates the egg cell before it reaches the uterus and fertilizes it within 24 hours of its release, then the two cells combine into one.

All of the 400,000 egg cells a woman will ever produce are already present in her ovaries when she is born, although the eggs are in an undeveloped form. That means that the egg that would become you was as old as your mother at the time you were conceived.

“I’m frightened of eggs, worse than frightened, they revolt me.”
– Alfred Hitchcock

International Condom Day

International Condom Day seeks to promote the use of condoms as a means of preventing unwanted pregnancies and sexually transmitted infections.

It is an informal observance celebrated in conjunction with Valentine’s Day. The holiday is also promoted by the AHF (AIDS Healthcare Foundation) in an effort to reduce the spread of HIV through safe sex practices.

The simple fact is that scientific research demonstrates that condoms are an effective and important tool in the worldwide fight against HIV/AIDS, as well as other sexually transmitted infections. Let’s consider some interesting nuggets of that large body of research:

• When it comes to HIV, using a condom makes sex 10,000 times safer than not using a condom. – Carey, Ronald F., et al. (1992)
• There is no medical reason why someone can’t use a condom. Even people with latex allergies can use them — there are latex-free condoms made of polyurethane and polyisoprene. – Hatcher, Robert A., et al. (2007)
• Condoms have been around a long, long time. The earliest known illustration of a man using a condom is a 12,000–15,000-year-old painting on the wall of a cave in France. – Parisot, Jeannette (1985)

Who binds with chains the poet’s wit,
The navvy’s strength, the soldier’s pride,
And lays the sleek, estranging shield
Between the lover and his bride.”
― George Orwell, Keep the Aspidistra Flying

• Condom availability in places of need around the world is increasing significantly, with 25.8 million female condoms provided through international and nongovernmental funding sources in 2009. Condom distribution increased by 10 million between 2008 and 2009. – UNAIDS (2010)
• The condom is one of the most accessible and inexpensive forms of birth control available. The cost of condoms is as low as $0.04 per unit. – UNAIDS (2010)
• Only 39 percent of American high school students are taught how to correctly use a condom in their health classes. Programs that teach young people about abstinence as well as contraception help youth to delay first sex and use condoms and other forms of contraception when they do have sex. – Kirby, Douglas. (2007)

“Staying in Africa, I think it will one day be admitted with shame that it might have been in error to say that AIDS is bad as a disease, very bad, but not quite as bad as condoms are bad, or not as immoral in the same way.” – Christopher Hitchens

And consider these other quite interesting facts about condoms:

• An average condom can hold a gallon of liquid. (The average healthy man over 24 produces a tablespoonful of 15 millilitres of sperm in a single ejaculation.)
• The oldest known condoms (that is to say, as in the oldest ones physically found) were discovered in a toilet in Dudley, England and were made from fish and animal intestine. They were dated around 1640.
• The term used by medical professionals and safer sex educators to refer to the phenomenon of decreased condom use is condom fatigue.

“Use a condom. The world doesn’t need another you.”
― Carroll Bryant

• 5 billion condoms are used every year, worldwide.
• The Chinese hold the world record for creating the largest condom. During the celebration of the World population Day in 2003, the people of Guilin, China, made a 80 meter x 100 meter condom and placed it on top of a hotel.
• The formal Danish word for condom is Svangerskabsforebyggendemiddel; whereas the Greeks employ the beautiful word προφυλακτικό.

“It’s the strange thing about this church, it is obsessed with sex, absolutely obsessed. Now, they will say we with our permissive society and our rude jokes, we are obsessed. No, we have a healthy attitude, we like it, it’s fun, it’s jolly, […] it’s a bit like food in that respect only even more exciting. The only people who are obsessed with food are anorexics and the morbidly obese, and that in erotic terms is the Catholic Church in a nutshell.” – Stephen Fry

Do ‘it’ for Denmark

Kan sex redde Danmarks fremtid? That is, can sex save Denmark’s future?

According to government statistics, Denmark posted a birth rate of 10 per 1,000 residents in 2013 — its lowest in decades. The nation’s birthrate was  9.9 in 1983.

Denmark’s perennially low birth rate places it with Germany (8.33), Japan (8.39) and Singapore (7.72). And the downward trend has left people worried in Denmark. Most couples say they want two or three kids, according to the Copenhagen Post, but one in five couples wind up childless.

To counter this trend, a bold and hilarious campaign has emerged. For the salvation of the country, a Danish travel company called Spies has organized the movement Do it for Denmark!; it wants Danes to act and act now — without precautions.

“This is Denmark. We are Danes. We keep our distance. We do not pick a seat close to strangers if other seats are available. We do not talk to strangers in the trains.”
― Steen Langstrup, Metro

Studies show that Danes have 46 percent more sex on holiday, and because more sex increases the chances for more children, the travel company Spies has called for a romantic break to save the future of Denmark.

To get the campaign of the ground, Spies will give prizes to couples who get pregnant while on vacations purchased through them.

Afterwards, upon successful sex, the couple is to shoot off a positive pregnancy test and medical records to the company. Then they may win three years worth of free diapers.

Börn er vis sorg, men uvis gläede.
― Children are definitive sorrow, but undefinitive joy.

And just in case Danes are confused by this whole pregnancy thing, the company has offered a helpful how-to on its website:

• Men, avoid tight pants. Even if you think they look good on you.
• Remember to exercise and maintain a healthy body weight.
• Avoid stress. Take a massage or try some yoga.
• Use Gravity. Lay down after sex for at least 15 minutes.
• Don’t forget to have sex – without using protection.

5/ii mmxiv

About 7,000 litres of blood are pumped through the human heart each day.

A Spotted Hyena or Crocuta Crocuta

An average healthy human can urinate 1,4 litres a day. That amounts up to 511 litres a year. It would take over 13 years to urinate the same amount of fluid the human heart pumps in a day.

The ancient Egyptians trapped hyenas as pets and fattened them for the table. In the Ethiopian city of Harar, ‘hyena men’ still feed on wild hyenas at dusk.

In Japanese, two different sets of characters spell out the word danshoku meaning either warm colour, or male homosexual sex.

Assuming an average healthy man over 24 produces a tablespoonful of 15 millilitres of sperm by ejaculating two or three times a day, he will produce about 5.5 litres (5.475) of sperm a year. At this rate it would take an average 24-year old over 454,545 years to fill an Olympic swimming pool; it would take 166,666,666 men to fill it in a day – about all Indian men between the age of 24 and 27.

See other: Quite Interesting Facts

Beetle Sperm

A man’s dietary habits influence the taste and scent of his sperm. For instance, eating a lot of meat as well as drinking alcohol and smoking results in a more pugnant smell, while it is said that eating pineapple and parsley helps improving the scent of the sperm.

Aleochara Curtula

Many species use smell as a way of getting the opposite sex to mate with them, and humans are susceptible to these pheromone-based mating rituals as well. The choices we make concerning our sexual partners are highly influenced by pheromones. Musk-like substances are still one of the most widely used ingredients in fragrances, and the smell of fresh sweat is often experienced as arousing.

But if a pleasant smell is associated with attractiveness, then why is the smell of sperm often so unpleasant? One could argue that it has nothing to do with afrodisiacs, because it concerns a scent that is being spread after the mating, not prior to.

With some beetles (like the Aleochara curtula), the unpleasant smell of sperm has found a clearer use; these beetles impregnate the females with a certain spermaphore containing a badly smelling chemical that serves to ward off other males (a sort of anti-afrodisiac). This way, the male can be certain that his offspring-bearing female won’t be bothered by other male beetles.

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Female Sperm

Female sperm is a term that refers to a sperm that contains an X chromosome, produced in the usual way by a male, referring to the fact that, when such a sperm fertilizes an egg, a female child is born.

A false colour image of human spermatozoa

However, for over 20 years, dating back to the late 1980s, scientists have explored how to produce sperm whereby all of the chromosomes come from an adult woman. In the late 1990s, the theory became a partial reality when scientists developed chicken female sperm, by injecting bone marrow stem cells from a female chicken into a rooster’s testicles. This technique proved to fall below expectations, however, and has not yet been successfully adapted for use on humans.

Creating female sperm was first raised as a possibility in a patent filed in 1991 by injecting a woman’s cells into a man’s testicles, though the patent focused mostly on injecting altered male cells into a man’s testicles to correct genetic diseases.

One potential roadblock to injecting a woman’s cells into a man’s testicles is that the man’s immune system might attack and destroy the woman’s cells. In usual circumstances, when foreign cells – such as cells or organs from other people, or infectious bacteria – are injected into the human body, the immune system will reject such cells. However, a special property of a man’s testicles is that they are immune-privileged, that is, a man’s immune system will not attack foreign cells – such as a woman’s cells – injected into the sperm-producing part of the testicles. Thus, a woman’s cells will remain in the man’s testicles long enough to be converted into sperm.

Scientists have discovered a method of creating partly developed sperm cells, otherwise known as spermatogonial stem cells, from the bone marrow of both sexes, entirely in-vitro, and is seeking funding to see whether such techniques can be used to make female sperm.

If created, a female sperm cell could fertilize an egg cell, a procedure that, among other potential applications, might enable female same-sex couples to produce a child that would be the biological offspring of its two mothers. It is also claimed that production of female sperm may stimulate a female to be both the mother as well father – similar to asexual reproduction – of an offspring produced by her own sperm even though many queries both ethical as well as moral may arise on these arguments.

Given the importance of procreation to critics of same-sex marriage, the development of human female sperm and children so born may alter the debate.

Fellatio

Fellatio is oral sex performed upon the penis. It may be performed to induce male orgasm and ejaculation of semen, or it may be used as foreplay prior to sexual intercourse.

Related to fellatio, Deep-throating is an act in which a man’s entire erect penis is inserted deep into the mouth of a partner, in such a way as to enter the receiving partner’s throat. It may be difficult for some people to perform, due to the requirement of suppressing the natural gag reflex.

In ancient Greece and modern Japan, fellatio has been referred to as ‘playing the flute’. Also, the Kama Sutra has a chapter on auparishtaka or ‘mouth congress’. The first known use of the term ‘fellatio’ is around 1893. Further English words have been created based on the same Latin root. A person who performs fellatio upon another may be termed a fellator. Because of Latin’s gender based declension, this word may be restricted by some English speakers to describing a male. The equivalent female term is fellatrix.

The receiver of oral sex is in a position of psychological if not physical vulnerability, and thus is potentially weaker. Bringing a person to climax is a form of exerting control over that person’s physiology and emotions.

The third-century Roman emperor Galienus called fellatio ‘lesbiari’ since women of the island of Lesbos were supposed to have been the introducer of the practice to use one’s lips to give sexual pleasure.

The Ancient Indian Kama Sutra, dating from the first century AD, describes oral sex, discussing fellatio in great detail and only briefly mentioning cunnilingus. However, according to the Kama Sutra, fellatio is above all a characteristic of eunuchs – or, according to other translations, of effeminate homosexuals or transwomen similar to the modern Hijra of India – who use their mouths as a substitute for female genitalia.

Kama Sutra Illustration

The Kama Sutra’s author states that it is also practised by so-called unchaste women but mentions widespread traditional concerns about this being a degrading or unclean practice, with known practitioners being evaded as love partners in large parts of the country. He seems to agree with these attitudes to some extent, claiming that a wise man should not engage in that form of intercourse while acknowledging that it can be appropriate in some unspecified cases.

In Tantric yoga, the same emphasis is placed on the retention and absorption of vital liquids and Sanskrit texts describe how semen must not be emitted if the yogi is to avoid falling under the law of time and death.

In Islamic literature, the only form of sex that is always explicitly prohibited within marriage is sex during menstrual cycles. But the exact attitude towards oral sex is a subject of disagreements between modern scholars of Islam. Authorities considering it objectionable do so because of the contact between the supposedly impure fluids emitted during intercourse and the mouth. Others emphasize there is no decisive evidence to forbid it.

As late as 1976, some doctors were advising women in the eighth and ninth months of pregnancy not to swallow semen lest it induce premature labour, even though it is now known to be safe. Fellatio is sometimes practised during pregnancy as a replacement for vaginal sex by couples looking to engage in a sexually pleasurable activity while avoiding the difficulty of vaginal intercourse during the later stages of pregnancy.

Semen ingestion has also had central importance in some cultures around the world. In the Papua New Guinean Baruya culture, there is a secret ritual in which boys give fellatio to young males and drink their semen, in order to re-engender themselves prior to marriage.

Among the Sambia people of Papua New Guinea, beginning at age seven all males regularly submit to oral penetration by adolescents in a six-stage initiation process, as the Sambia believe that regular ingestion of an older boy’s semen is necessary for a prepubescent youth to achieve sexual maturity and masculinity. By the time he enters mid-puberty he in turn participates in passing his semen on to younger males.

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