Female nursery web spiders (Pisaurina mira) benefit from consuming their mate

Abstract

The often coincidental involvement of cooperation and conflict in animal reproduction is epitomized by sexual cannibalism, which can lead to obvious male costs while simultaneously providing direct benefits to developing offspring. Male nursery web spiders (Pisaurina mira) avoid postcopulatory sexual cannibalism by wrapping females with silk. Here, we test the hypothesis that this silk wrapping results in a loss of consumption cost for females. In specific, we hypothesize that females lose out on potential fitness benefits associated with cannibalizing their mating partners. To test this, we paired females with males that were experimentally manipulated to prevent the silk wrapping of females, thereby increasing the likelihood of sexual cannibalism. Females either did not kill their mate, and thus consumed nothing, or did kill their mate. If females killed their mating partner, we allowed them to consume the male, consume nothing, or consume a cricket. We found no effect of female or male body sizes on the likelihood of females killing their mate. While our treatments did not affect the number of offspring females produced, females that consumed either a male or a cricket produced egg sacs faster than females that consumed nothing, suggesting a benefit of increased postcopulatory food consumption. Further, only females that ate a male had heavier and longer lived offspring, suggesting a benefit of sexual cannibalism specifically. Our results support the hypothesis that females can receive fitness benefits associated with sexual cannibalism.

Biomineralization of lithium nanoparticles by Li-resistant Pseudomonas rodhesiae isolated from the Atacama salt flat

“…TEM micrographs of purified nanoparticles produced by P. rhodesiae were obtained using the same microscope. Then, the size of NPs was determined using the Pixelstick software (Plum Amazing Software LLC, Princeville, HI, USA) to establish a size-frequency histogram [ 45 , 46 ]…”

Solifuge (camel spider) reproductive biology: an untapped taxon for exploring sexual selection

“…Or does it benefit females in some manner? In addition to instances of female ''catalepsy'' during mating, males of some spider species, such as the nursery-web spider Pisaurina mira (Walckenaer, 1837) reduce their likelihood of being cannibalized by physically restraining their female partners with silk during sperm transfer (Anderson & Hebets 2018). A series of behavioral studies on this system have revealed a benefit to males of silk-wrapping as well as a lost opportunity cost for females (Anderson & Hebets 2016, 2017Scott et al 2018).…”