Crickets Trade Health for Sexual Fitness

Crickets Trade Health for Sexual Fitness

High-quality sperm or a strong immune system? This is the difficult trade-off crickets face every day.

Australian scientists have discovered that male field crickets must choose between high-quality sperm and a robust immune system, highlighting a fundamental trade-off in evolution. This trade-off suggests that it’s impossible to have everything at once.

Professor Leigh Simmons and Benjamin Roberts from the University of Western Australia bred healthy male crickets with females and examined the offspring for sperm quality and three traits indicating resistance to disease infections.

In two of the traits, crickets with better sperm quality also showed stronger immunity. However, for the third trait, crickets with relatively higher sperm quality had lower levels of the enzyme lysozyme, which is a crucial tool in combating bacterial infections.

The findings support the hypothesis that trade-offs allow males to signal their immune system quality to females through their sexual traits.

Evolutionary biologist Rob Brooks from the University of New South Wales commented: “Evolutionary theories have long suggested this type of trade-off, so it’s fascinating to see it demonstrated in an actual mechanism. The true value of this research extends beyond crickets – it provides insights into the reproductive mechanisms of many other species.”