Molecular Biogeography Of Ocellarnaca From China

The genus Ocellarnaca Gorochov,2004 belongs to the subfamily Gryllacridinae(Orthoptera: Stenopelmatoidea: Gryllacrididae).To date,Ocellarnaca includes 14 species worldwide,10 species of which are recorded in China.In this study,based on morphological and molecular delimitation,the species boundaries of this genus was further determined,and phylogenetic relationship reconstruction,divergence time estimation,Maxent model prediction and ancestral region reconstruction for 89 samples of the genus were performed based on the gene sequences of COI,H3 and ITS.The results are as follows:1.The results of two species delimitation methods(ABGD and jMOTU)show the species of Ocellarnaca classified into 8 species(subspecies)which supported the taxonomic status of Ocellarnaca angulata Gorochov,2004,O.braueri(Griffini,1911),O.brevicauda Li,Fang,Liu & Li,2014,O.conica Bian,Shi & Guo,2013,O.furcifera(Krauss,1906)and O.fuscotessellata(Karny,1926).O.emeiensis Li,Fang,Liu & Li,2014 was divided into 2 OTUs suggested to be two subspecies,namely O.emeiensis fissa ssp.nov.,and O.emeiensis emeiensis Li,Fang,Liu & Li,2014.2.The results of sequence composition and mutation analysis of gene fragment indicated that COI and combined gene have AT bias,and variable sites accounted for 28.57% and 19.74% respectively;H3 and ITS gene sequences have GC bias,and variable sites accounted for 7.69% and 18.35% respectively.Therefore,the sequences of COI gene were the most variable,and H3 gene were the most conserved.3.Phylogenetic relationship of Ocellarnaca: phylogenetic trees constructed by the bayesian method and the maximum likelihood method have the basically same results that forming 8 evolutionary branches.The monophyly of Ocellarnaca was supported.O.furcifera was located at the base of the tree,and then the species of the genus were divided into two major branches.BEAST analysis shows that O.fuscotessellata was the first separated in 45.49 Mya(about Mid Eocene),two branches were separated about 37.93 Mya.4.Maxent modelling was used to predict potential distribution areas in the Last Glacial Maximum(LGM),the mid-Holocene,the present-day(1970–2000)and future(2070)in order to understand speciation processes and responses to climate change in the genus.The variables bio-12(Annual Precipitation)and bio-14(Precipitation of Driest Month)had the highest contribution rate;the permutation importance of bio-07(Temperature Annual Range(BIO5–BIO6))was the most important.The general distribution trend of the genus was towards southern Yunnan,Guangdong and southeastern Fujian,Hainan and Taiwan.5.Based on the analysis of reconstructing the ancestral region,it was concluded that the species of Ocellarnaca in China first appeared in Fujian and Guangzhou coastal areas(Guangxi and Guangdong)with two dispersal routes: one was spread eastward along the Nanling mountains and westward along the Western mountain plateau(E),namely the north of YunnanGuizhou Plateau at the same time,and finally reached the southwest edge of the Sichuan Basin.The other was to the northwest of the Yunnan-Guizhou Plateau,then to the Southern Mountain Areas of Yunnan(C).O.conica of Hainan(A)was formed by geographical isolation after spreading from Guangdong.Due to dispersal,O.emeiensis fissa ssp.nov.in the southern Yunnan differentiates into O.emeiensis emeiensis.