reproduction

Tag archives for reproduction

I came across an article published in Physiological Reviews with a title so irresistible (Estrogens in Male Physiology), I just had to read it. While I knew that males have estrogen, this article impressed me with the numerous things estrogens are associated with, some of which were new to me and highlight how important estrogens are to…

The story begins in 1999 when Leonie, a zebra shark (aka a leopard shark in Australia), was captured from the wild. In 2006 she was transferred to Reef HQ Aquarium in Queensland, Australia where she met her mate. By 2008, she had started laying eggs and the pair had multiple litters of offspring through sexual reproduction. After her…

Why orcas go through menopause

Orcas are one of only three species of mammals that go through menopause, including humans of course. A new study published in Current Biology may have discovered why this happens in killer whales. Examination of 43 years worth of data collected by the Center for Whale Research and Fisheries and Oceans Canada, revealed a remarkable finding…

The cost of male pheromones

A new study conducted by researchers at Northwestern University examined the costs of reproduction in roundworms, otherwise known as C. elegans. They discovered that male roundworms can send two kinds of pheromones that prime females for reproduction. One type of pheromone they studied sparks the onset of puberty in young female worms while the other prolongs fertility in aging females. …

City life makes bigger spiders

A new study from researchers at the University of Sydney shows that golden orb-weaving spiders (Nephila plumipes) that live in the city are larger and produce more offspring as compared to country living. When they say the spiders are big, they mean really big. The females can reach up to 20-25mm (males are only ~5mm).…

I was just digitally flipping through a new book called “Crime Against Nature“, which describes various reproductive behaviors in the animal kingdom. It is written by an artist, Gwenn Seemel, not a scientist, so I cannot vouch for the scientific accuracy of the book as a whole. However, the illustrations are quite nice and the content is seemingly scandalous,…

Dr. Tim Jessop from the University of Melbourne, Australia and colleagues  spent eight years following 400 Komodo dragons (Varanus komodoensis) to learn more about their growth rate, lifespan as well as differences between populations on isolated Indonesian islands. Their most surprising finding was that female Komodo dragons only live an average of 32 years whereas males live for about 60 years.…

Studies of guppies show that bigger brains may mean “smarter” fish, but less offspring. Credit: Marrabbio2/Creative Commons   …at least for guppies. Dr. Alexander Kotrschal and colleagues at Uppsala University (Sweden) either shrank or grew the brains of guppies over multiple generations to create animals with up to 8-10% variations in brain size. To test for “smartness” they had…