It is small and delicate, but it boasts a reproductive system that would make any other living species burst with envy. By analyzing his testicles, the researchers discovered something that revolutionized some previous mating theories. (Elisabetta Intini, 24 November 2010)
Calling it "gifted" is almost an understatement. The grillastro affine (Platycleis affinis), a particular type of cricket widespread in our peninsula, has just entered the gold record of animal records for a very particular record: its testicles reach a weight equal to 14% of its total tonnage (so to speak, it would be as if those of an adult man weighed 5 kilos each). The insect therefore deservedly won the title of animal with the most bulky male genital glands - in relation to its size - tearing the Drosophila bifurca qualification, a fruit fly whose testicular-body weight ratio reaches "as soon as" 10, 6%.
So much scene, little … "surrender". A team of researchers from the University of Derby (Great Britain) measured the size of the reproductive system of 21 species of crickets, noting that the proportion of the testes varied considerably from species to species. However, as might be expected, the record size of Platycleis affinis does not correspond to an overproduction of seminal fluid. The specimens with the bigger testicles in fact, produce a smaller quantity of sperm, which, scientists explained to the BBC, suggests the hypothesis that the size of the testicles "is due to the high number of different partners to fertilize, rather than the attempt to have greater reproductive success with a single partner ".
Subverted rules. The research, therefore, would seem to show that the size of the testicles is directly proportional to the sexual promiscuity of their "owner": the greater the attributes, the higher the number of companions with whom he will be able to mate (and therefore, the higher the possibility to secure a lineage). At least for the crickets, however, it does not seem to be worth the rule that larger testicles also produce a greater quantity of sperm, previously supported by many experiments on vertebrates (among these, also various species of primates). "An important lesson to be learned is that we should not expect the same rules to apply equally to all animal species, but there may be an alternative, " said Karim Vahed, head of the study.
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