For some creatures, two sexes is simply too stifling. For example,
crustaceans of the genus Tanais have two distinct forms. In one
form the males have numerous smelling threads, in the other form males
have more powerful pincers to hold the female during copulation. Thus,
one type of male finds many females but cannot secure them as easily;
the other type finds fewer but hangs on to them with great tenacity.
As a result both male types reproduce approximately the same.
dating scene becomes even more complex in the protozoan world. Creatures
in the genus Chlamydomonas, a type of single-celled algae, have
no less than 10 sexes. Rather than regard them as "male" and
"female", most biologists simply refer to them as mating type
plus and minus (mt+ and mt-), and note which plusses mate with which
minuses (though they don't have too--all chlamydomonas organisms are
perfectly happy reproducing on their own). The record holder for the
most number in a species is the single-celled Paramecium amelia,
which has eight different sexes. Makes sense--if bisexuality doubles
one's chances of getting a mate, just think of how well octosexual
The ignoble tapeworm, 3,500 species of flattened, intestinal
parasites that's the scourge of vertebrates the world over, also has
the most sexual organs of any living being. The adult tapeworm has a
head, or scolex, equipped with tiny hooks for attachment to the
intestinal lining of the host. From the scolex body segments sprout,
each containing a complete set of sexual organs, both male and female.
Once properly situated a typical worm grows anywhere from a millimeter
to nine meters long (0.04 inches to 30 feet) and screws itself over,
literally. Each segment mates with itself and grows eggs, which are
washed away by the host's digestive wastes. Under the right conditions
these suckers can get pretty big: the largest ever found measured over
70 meters in length (230 ft.) and had over 11,000 segments, or over
22,000 individual sexual organs.
As any rational person would have expected, the largest organisms ever
to exist on earth would also have the largest endowments. Among land
animals, African bull elephants lead the pack with their 5 to 6 ft.
extremities. Whale penises, called dorks (yes, when called a dork in
grade school you were actually being compared to a whale schlong), are
the largest in the world, the blue whale being the champ with phalli
approximately 10 ft. long and 1 ft. in diameter. Its smaller cousins,
notably the appropriately named humpback and sperm whale, have penises
that measure 9 feet or so. Makes you wonder if this is what Melville
had in mind when he chose the title Moby Dick (snicker).
you measure as a percentage of body length things are a little different.
Goose barnacles, with inch-and-a-half-long appendages, rate about 150%.
Unbeatable, you think, until you learn that a rare species of Alpine
banana slugs (Ariolimax dolichophallus) measure 6-inches long
and possess 32.5-inch tumescences, or 542% times their body length.
The largest for land animals belong to, unsurprisingly, the African
bull elephant, with testes that weigh around 4.4 lbs. each and encompass
a volume of 184 cubic inches—about the size of a large football.
the REAL hands-down winner is the northern right whale (Eubalaena
glacialis), which has a pair of gonads that can weigh up to 2,200
lbs. The enormous size is an evolutionary adaptation caused by a natural
phenomenon known as "sperm competition." When the females
of the species come into heat, she's immediately mobbed by 30 or so
love-starved males who shove one another as they try to jockey into
position. When one male finishes (typically this takes 30 seconds),
another takes up the slack. And another. The hope of each is to wash
out a competitor's sperm with unknown gallons of their own, thereby
ensuring that their genes will continue.
In most animals, sperm production is much like budget reform proposals:
created in great quantities with minimum effort put behind each. But
not all creatures follow suit. Drosophila bifurca, a distant
relative of the fruit fly, produce sperm 6 cm in length—20 times longer
than their entire body length.
Belongs to (what else?) the female blue whale, who naturally must park
the 10-foot organ of the males. The vulva is basically a long groove
along the underside of the female, with a normal length of 6 to 8 feet
before elongating to accommodate the male. After coition it expands
to some 23 feet in length to hold the baby calf.
as a percentage of body mass, the undisputed winner is the bumblebee
threadworm (Sphaerularia bombi). After being impregnated, the
female seeks out a queen bee as a host (hence its name). After settling
in her uterus and vagina begin to expand, growing until they encompass
the entire genital tract, and eventually her entire being—and keeps
right on going. I quote from The Natural History of Nematodes
(G. Poinar, 1983): "…in Sphaerularia bombi the entire uterus
is [expelled] and the expanding organ soon surpasses the length of the
nematode. When the uterine cells eventually finish their growth, the
reproductive system dwarfs the now moribund female…" The reproductive
organs may grow up to 30 times the length of the original female and
300 times the volume, for an overall increase of a whopping 30,000%.
Out of the 18,000 species of mammals, the tenrac (Centetes ecaudatus),
a hedgehog-like insectivore indigenous to Madagascar, has the largest
number with 22 to 24 nipples.
Before the onset of sex, the earliest inhabitants of the primordial
soup reproduced by fission, meaning they split off clones of themselves
by dividing into two daughter cells. While this was great when conditions
were favorable, the lack of genetic diversity left the species vulnerable
if the climate took a turn for the worse. Sexual reproduction is believed
to have originated around one billion years ago, when microorganisms
began to fuse with one another to share genetic information. Naturally
the smaller, stationary, and starving cells sought after the larger,
motile ones rich in nutrients to get the best possible offspring and
to last through the lean times; in other words, they were gigolos. The
arrival of sexual reproduction enabled a greater variety of organisms
to evolve, permitting the development of more complex creatures. Thus,
the entire animal kingdom owes its existence to the selfish motivations
of a few randy protozoa.
Snakes, surprisingly, are the champs in the animal kingdom when it comes
to pure sex endurance, no doubt due to the fact the male has a spiked
penis, making it difficult for him to escape readily. Typically they
remain in union from six to twelve hours. The record is held by a pair
of rattlesnakes who remained in copulatory connection for no less than
Mosquitoes, which mate on the wing, perform a sex act that lasts only
Whether you think of them as cuddly pets or plague carriers, rodents
reign supreme when it comes to repeated mating. I quote from "Copulatory
Behavior of Small Mammals" (Journal of Comparative Psychology,
v. 39): "In the golden hamster Mesocricetus auratus...copulations
may continue for half an hour or more; young males may copulate only
a few times, while older ones may attempt copulation as many as 175
times; for adult males, between 65 and 75 copulations per mating may
be considered as average."
The Alpine black salamander (Hynobius nigrescens) has an interesting
property: the higher the elevation it inhabits, the longer its gestation
period becomes. At 4600 ft. or higher the gestation period can last
a whopping 38 months.
The holder of this dubious record is the American slipper snail (Crepidula
fornicata—the scientific name alone should clue you in on their
kinky predilections). All slipper snails begin life 100% male. The chain
begins when a young snail reaches sexual maturity, becomes stricken
with ennui, and attaches itself permanently to some fixed object. At
the same time it undergoes a complete identity crises and becomes female.
Shortly afterward, another male snail comes along, then mounts and copulates
with the first one. It, too, abandons the motile life and remains in
permanent copulatory union with the first one for the remainder of their
lives. A third snail then comes along and mounts this second snail,
which in turn becomes female. This procedure continues until there are
up to fourteen individuals in the perpendicular chain.