The Multi-paternal Pattern Of Elaphe Schrenckii (Elaphe Schrenckii), Dinodon Rufozonatum (Dinodon Rufozonatum) And Ptyas Korros (Ptyas Korros)

An organism's fitness depends on its ability to successfully produce offspring.To enhance offspring survival rate and thus offspring fitness,parents should adopt adequate mating strategies.In many species,females with multiple males to mate and increase the quantity and quality of offspring.Multiple paternity is a phenomenon in which offspring within a single clutch or litter can be sired by more than one male.Multiple paternity is universal in natural populations of reptiles,which means for reptiles,not only to have multiple matings,more important is the female should have the capacity to store sperm.That males and females mate multiple times should be driven by direct(male parental care,providing resources and plenty of sperm)and/or indirect(preferred hypothesis,strong sperm competition,the choice of female secret,bets)benefits.Animals used in this study included:15 adult females of Elaphe schrenckii collected from Liaoning(Northeast China),and their 207 offspring;15 adult females of Dinodon rufozonatum collected from Xiaoshan(Zhejiang,East China)and Quanzhou(Guangxi,South China),and their 117 offspring;17 adult females of Ptyas korros collected from Jiangshan and Taizhou(Zhejiang),and their 187 offspring.Pregnant females were fed under natural conditions as in the wild until they laid eggs.Post-oviposition females were weighed and measured for snout-vent length,head length,head width and tail length,often less than 6 h post-laying.Newly hatched offspring were weighed and measured often less than 6 h post-hatching.Extract genome from the tail of the snake.Select high polymorphism of microsatellite loci primers.Remove female allele from offspring by COLONY 2.0.Computing the genetic similarity of offspring to complete the occurrence of multiple paternity.The results showed that 1)fourteen clutches(93.3%)is multiple paternity and one clutch(6.7%)is a single parent in E.schrenckii;2)nine clutches(60.0%)is multiple paternity and six clutches(40.0%)is a single parent in D.rufozonatum;and 3)fpurteen clutches(82.4%)is multiple paternity and three clutches(17.6%)is a single parent in P.korros.Comparing phenotypes between offspring produced by polyandrous and monandrous females of three snake species,I found that polyandrous females gained more benefits than monandrous females.Moreover,genetic diversity was certainly higher in offspring produced by polyandrous females.Monandrous females gained more benefits than polyandrous females,as revealed by the fact that offspring produced by polyandrous females were relatively heavier and larger in snout-vent length,head length,head width and tail length.Moreover,genetic diversity was certainly higher in offspring produced by polyandrous females.Multiple paternity can enhance a female's fitness.However,reproductive costs associated with multiple paternity impose a constraint on this pattern of mating strategy in snakes.Data from collected form E.schrenckii,D.rufozonatum and P.korros consistently showed in each polyandrous clutch there were one or two superior males that sired more offspring.Comparing phenotypes between offspring produced by superior and inferior males of the three snake species,I found that the differences in phenotypes of offspring produced by superior and inferior males were obvious significant in D.rufozonatum and P.korros,but not in E.schrenckii.I speculated that mother can itself into the offspring of matter and energy is relatively rich for the high fitness females,the influence of the offspring from the father is relatively small.With the lower fitness females,the matter and energy of offspring from the matrix is restricted.At this point,females perform multiple mating is used for merit.Females can be filtered on sperm.Fertilization is not a random process,but is likely to be an indirect choice from male to female.The sperm of different male compete with each other.The probability of aiding in egg is relatively high for high quality of male sperm.The effect for the offspring from fathers is more obvious.For the snake with lower fitness,advantaged fathers have obvious advantages.However,for the high fitness of snakes,the difference of offspring between advantaged fathers and disadvantaged fathers is no significant.There is no advantage for advantaged fathers.