Two fish tales to tell today:
First: David Reznick of UC Riverside and colleagues found that female guppies go through menopause, just like humans (and gorillas, as blogged here before)!
Guppies typically reproduce about every 30 days and lay eggs approximately 20 times throughout their lives. The researchers found that as female guppies aged, they began to skip litters or even stop reproducing for extended periods of time, effectively ceasing to reproduce after a certain age. In other words, the guppies were going through a fish version of menopause.
Second: Molly Morris of Ohio University found that young female swordtail fish prefer males with symmetrical patterns, an indicator of good genes - however, their mating preference changes as they age - older females prefer males with asymmetric markings.
The reason for the "switch" is not yet understood. The researchers are planning experiments to determine if it’s simply part of a female’s development over the course of her lifetime, or if it is in some way due to the experiences females have. "Older, larger females will have had more mating experience," Morris said.
Fish menopause story | Fish mating preference story