Patterns Of Multiple Paternity In Two Species Of Venomous Snakes,Naja Atra And Gloydius Brevicaudus

I characterized eight polymorphic microsatellite loci from the short-tailed pit viper Gloydius brevicaudus genomic libraries,using 12 individuals collected from a population in Xiaoshan,Zhejiang,East China.These markers revealed a relatively high degree of genetic diversity(7-16 alleles per locus)and heterozygosity(Ho ranged from 0.667-1.000,the average is 0.854 and He ranged from 0.822-0.960,the average is 0.916).No locus exhibited significant deviations from the Hardy-Weinberg equilibrium after sequential Bonferroni correction.There was no evidence of linkage disequilibrium among pairs of loci in the samples.These microsatellite markers,revealing the high level of polymorphism,will be useful for future studies focusing on gene flow,population structure and evolutionary history of G.brevicaudus.I studied for the first time the occurrence of multiple paternity in the Chinese cobra(Naja atra)using 9 microsatellite loci,and in G.brevicaudus using 8 microsatellite loci.Female reproductive success and offspring fitness were also examined in N.atra.Paternity was assigned for 15 clutches of N.atra and 12 clutches of G brevicaudus.My data demonstrated that multiple paternity occur in 40%of clutches of N.atra,and in 83.3%of clutches of G.brevicaudus.Polyandrous females did not differ from monandrous females in mean SVL,nor in post-oviposition body mass,fecundity(clutch or litter size),offspring size(clutch or litter mean egg or neonate mass)and reproductive output(clutch or litter mass)in the two snakes.For N.atra,polyandrous clutches were sired by 3-5 males,with a mean of 3.8;Size and morphology of hatchlings overall were affected by both sex and mating strategy,but not by their interaction;female hatchlings were longer in SVL but did not differ from males of the same egg mass in body mass,head length and head width,body mass and head length were greater in hatchlings produced by polyandrous females after accounting for egg mass,and the other two hatchling traits were not affected by mating mode;hatchlings produced by monandrous females did not differ from those produced by polyandrous females in survival rate.For G.brevicaudus,polyandrous offsping were sired by 2-5 males,with a mean of 2.6.Size and morphology of neonates overall were affected by mating strategy,but not by sex and the interaction between sex and mating strategy.SVL,body mass,head length and head width all were greater in neonates produced by polyandrous females.The results of this study support the hypothesis that viviparous snakes should have larger proportion of multiple paternity than oviparous snakes.Future work could usefully investigate other lineages of snakes with both oviparous and viviparous species in a phylogenetic context to determine whether the hypothesis is generalisable to all snakes.The results of this study do not support the hypothesis that the genetic monogamy by females is a broader phylogenetic characteristic of elapid snakes.