Scientists from the University of Auckland (New Zealand) have discovered a rare spider species consisting of three types of males. The results of the research were published in a scientific journal. behavioral ecology.
We are talking about the male New Zealand harvester Forsteropsalis pureora, which includes alpha, beta and gamma males. The first two can be recognized by their large size and chelicerae, which are broad and short in alpha males and long and slender in beta males. Gamma males are much smaller than their counterparts, and their chelicerae are also small. Therefore, instead of fighting for the female, they approach her unnoticed and try to fertilize her.
A team of zoologists led by Erin Powell set out to find out why some F. pureora males are alpha or beta while others are gamma. Researchers believe that men’s lives are affected by leg loss at a young age. Harvesters often throw off their limbs to escape a predator, but are then unable to regrow them, negatively affecting their lives.
Scientists believe that the immature males of F. pureora, who have lost one or more of their legs, later turn into scales, and their relatives who escaped this fate are alpha or beta.
To test this theory, the researchers examined 86 adult male Forsteropsalis pureora, 63 of which were alpha and beta (assessed together in this study) and 23 were gamma. It was seen that 48 people caught by scientists lost one limb and two lost two limbs during their lifetime. By the appearance of scars left after the autotomy, the scientists determined which boys were in the early stages of development (there were 25) and which boys lost one or more of their legs after reaching puberty.
According to the research, 82% of gamma men are individuals who lost their legs at a young age. Only 9% of individuals who survive autotomy before reaching sexual maturity are representatives of alpha and beta.
According to the authors’ calculations, the loss of a limb or two in the early stages of development increases the male’s probability of having a gamma 45 times. It is not yet clear which mechanism is responsible for this developmental pathway. It is possible that males who lose their legs at a young age are not foraging efficiently enough, thus not having enough resources to become a large alpha or beta.
Biologists formerly at James Cook University saidHow spiders change their venom.