Bern researchers learn: Good frog fathers have smaller testicles

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In frogs from the glass frog family, fertilization occurs outside the body: Females lay unfertilized eggs on the leaves, and males distribute their sperm on them. In some species of glass frogs, males protect and care for their offspring, while others do not care for the offspring, the University of Bern announced on Thursday.

In a study in the journal Proceedings of the Royal Society B, researchers have now shown a link between this offspring care and testicle size. “We were surprised at how clearly these connections were visible in glass frogs,” co-author Eva Ringler, professor of behavioral ecology at the University of Bern, said in the statement. In total, the research team examined 37 different species of glass frogs native to the tropical rainforests of Central and South America. In 11 of these species, males care for the young, and in the others they do not.

There’s evolution behind it

Researchers suspect this is due to evolution. “When a male protects his own claw, he reduces the risk of fertilization by other males,” Ringler explained. Because external fertilization carries the risk of “spawning piracy”. Thus, other male frogs manage to distribute their own sperm to new eggs, thus fertilizing the eggs that have not yet been fertilized with the sperm of the first mating male.

The researcher explained that protecting and caring for eggs reduces the selection pressure for more sperm production and therefore larger testicles. The smaller the testicles, the lower their potential to produce sex cells.

(SDA)

Source : Blick