Octopus with Longest Gestation

Scientists have observed a deep-sea octopus (Graneledone boreopacifica) brooding a clutch of eggs at a site in the Pacific Ocean for roughly 53 months, longer by far than any other known species.

Bacteria in Healthy Placentas

Long thought to be sterile, a new study has found that the placenta is home to a non-pathogenic bacterial community that is similar to that found in the mother's mouth and that may be linked to poorly understood pregnancy disorders.

Orca Undergo Menopause

Researchers have found that female killer whales (Orcinus orca) undergo menopause as they age, along with humans and pilot whales one of only three species known to do so, living 50 to 60 years past their reproductive age presumably as an evolutionary advantage to increase the survival rates of young males and their offspring.

Mouse Eggs From Stem Cells

Researchers have produced lab-made viable egg cells from mouse stem cells, capable of being fertilized and growing individuals to birth, maturity and being successfully reproductive themselves.

Children of Older Fathers

An analysis of the DNA of young adults finds that the genetic makeup of sperm changes as a man ages, and that children born to older fathers and even older paternal grandfathers appear to inherit this genetic bias for a longer lifespan.

Ovaries on the Outside

Researchers have discovered a new species of acorn worm (Allapasus aurantiacus) living on the deep ocean floor that is unique in that it has its ovaries attached to the outside of its body, a design that possibly facilitates fertilization from the male.

Women Produce New Eggs

Researchers have recently discovered a type of stem cell in women's ovaries that can produce new eggs when grown in the lab, challenging the long-held belief that women are born with a finite number of eggs and instead may produce at least some new eggs through their reproductive years.

Self-Fertilizing Scales

Females of an agricultural pest known as the cottony cushion scale have been found with female offspring that contain excess sperm from the father growing in their tissues, effectively becoming a self-fertilizing variant in a species that normally reproduces sexually.

Dolphins Killing Porpoises

Three acts of unprovoked dolphin aggression have been documented with animals off the coast of California in which groups of bottlenose dolphins rammed and drowned lone porpoises and then played with the carcass, supposedly due to frustrations of breeding males without access to females.

Sperm Grown from Scratch

For the first time, mouse germ cells have been grown into viable sperm cells outside the testes and successfully fertilized eggs to produce healthy embryos, a development that could lead to new treatments for infertility.

Boas by Virgin Birth

A boa constrictor has had two litters of 22 offspring with no father, an exceedingly rare case of parthenogenesis in vertebrate species and with the young snakes having sex-determining WW chromosomal pairs, a genetic combination not found in nature.

Artificial Ovary Developed

Researchers have developed the first functional artificial human ovary composed of a three-dimensional model from donated tissue containing all three ovarian cell lines, with the prototype able to mature human oocytes from early antral follicle to full maturity.

Termites Reproduce Asexually

Certain termite "primary" queens have been found to reproduce both sexually and asexually during their lifetimes to maintain the genetic diversity within their colony.

Fish Fossils Reveal Internal Sexual Reproduction

Scientists at Museum Victoria in Melbourne and the Natural History Museum in London have discovered internal sexual reproduction in early fish fossils, some 30 million years earlier than previously believed.

Fossils of the 380 million-year-old fish Incisoscutum richiei, or armored placoderm fish, revealed females carrying fossilized embryos. This provides the earliest evidence for internal sexual reproduction and internal incubation of offspring that included bearing live young. Subsequent analysis of the male of the species also uncovered a previously overlooked pelvic fin not present on the female, supposedly used to grip the female during reproduction.

Researchers expected prehistoric fish to have a much more simple reproductive strategy, similar to the external fertilization of today's fish species where sperm and egg combine in the water and embryos develop outside the body. The fossilized fish and embryos are from the Gogo dig site in Western Australia and are the oldest known evidence of a vertebrate mother.

These results were published in the February 26th edition of Nature.

Source: Yahoo!

Mosquitoes Harmonize Before Mating

Scientists at Cornell University have discovered that male and female mosquitoes will synchronize their wing-beat frequencies and produce harmonic calls before mating.

Male mosquitoes (Aedes aegypti) typically beat their wings at 400 Hz (beats per second) and females at 600 Hz. But when the two come within audible distance of a few centimeters, both male and female wing beats approach 1200 Hz, a harmonic of each individual's normal rate. This rate is greater than what was believed to be the mosquitoes' upper hearing limit.

In addition to wing beats, each mosquito also adjusts the resonance of their thoracic box to produce harmonic mating calls. The female will settle at her third harmonic (three times her fundamental frequency) and the male will settle at his second harmonic (two times his fundamental frequency). This also demonstrates that the female mosquito is not deaf, as was previously believed.

Knowing the details of mosquito mating and reproduction helps researchers develop effective pest control strategies. If the reproductive cycle can be interrupted, the mosquito population in places at risk of diseases such as dengue or yellow fever can be controlled.

This study is available online on January 8th and in a February edition of Science.

Photo: ScienceDaily