Effects Of Body Lipid Content Of The Wolf Spider Pardosa Pseudoannulata On Its Courtship,Mating And Sexual Cannibalism

Courtship,mating and reproductive behaviors have been the hot spots of ethology.Courtship and mating of spider is species-specificity,especially the males of the wolf spiders possessing complex courtship behavior.Some wolf spiders have sexual cannibalism.Therefore,the wolf spiders appear to be an excellent model system for addressing animal courtship and mating as well as sexual cannibalism.Here,we selected the wolf spider Pardosa pseudoannulata as the model system to shed some light on the effects of lipid content of the P.pseudoannulata on its courtship,mating behavior and sexual cannibalismFirst,in order to get several groups of flies which differed in lipid content,we cultivated them on various medium with different content of sugar.And we are expected to get wolf spiders differed in lipid content through feeding on these fruit flies.Drosophila simulans medium with three sugar content(concentration gradient)wered prepared and each gradient were poured into six culture tubes.We marked it with A,B and C descended by the sugar content.Then it was inoculated with D.simulans.After the larvae matured,about 100 D.simulans from each culture tube were taken as a sample for measuring the lipid content.We found that group A of D.simulans has significant higher lipid content compared to group B,and group B has significant higher lipid content than group C.100 submature male and female P.pseudoannulata were collected and divided into three groups,respectively.Each group comprised 30 individuals.We used the three groups of D.simulans to feed the certain group of spiders and measured their lipid content in the third day after their maturation.Results showed that there were significant higher lipid content of the spiders of group A than those of group B and C,and the lipid contents of the spiders of group B were significant higher than those of group C.We have got higher lipid spiders(group A)and lower lipid spiders(group C)both in male and female spiders in contrast to the control group(group B).We paired female or male spiders from group A or C with male or female spiders from group B for the mating tests,respectively.We recorded the behavioral patterns of male pedipalps,male forelegs,body and abdomen during male courtship.The time of courtship latency and courtship duration as well as mating latency and mating duration were recorded.The number of sexual cannibalism occurred in the pairs included females from group A or C were calculated.Results showed that there were no significant differences on courtship rate,courtship intensity,courtship latency,courtship duration,mating success between males with different lipid content.Female spiders were not inclined to cannibalize males with higher lipid.Meanwhile,the courtship intensity of male spiders significantly enhances the rate of mating success.We completed a total of 109 mating pairs.Only 4 of them had no courtship behavior and these males were cannibalized by females before mating,courtship rate was 96.3%.4.6%of P.pseudoannulata virgin females cannibalized the approaching males before mating and 31.2%of P.pseudoannulata virgin females cannibalized the males after mating.90 pairs mated successfully and the mating success was 82.6%.Fresh weight of the female spiders significantly affects the incidence of cannibalism after mating.We also found that there was a significant positive correlation between lipid content and fitness of female spiders.On the one hand,females with higher lipid had a shorter latency for producing egg sacs.On the other hand,the survival days of the spiderlings hatched from the high-lipid females under the condition of no water and no food at 15 "C was significant longer than low-lipid females.No difference was detected in the number of eggs and spiderlings hatched by females with different lipid content.11 mated female spiders were dead exceptionally.Only three mated females didn't produce egg sacs,but almost all of them would eat their egg sacs and some of them would lay new egg sacs.Among the 76 egg sacs produced by female spiders,only 35 of them hatched.The hatching rate of the egg sacs was 44.7%.There were no significant differences on spawning rate,hatching rate,offspring numbers,offspring size and fitness between female spiders with different lipid contentWe determined the differences of male survival days when they were directly exposed to female dragline,male dragline and the blank treatments.The results showed that male survival days on female dragline were significantly shorter than those on male dragline,while there were no significant difference between female dragline and the control treatment group.There were no differences in lipid content after the males were dead between the three treatments.