Population genetic structure in wild and aquaculture populations of Hemibarbus maculates inferred from microsatellites markers

The objective of this study was to investigate 4 aquaculture populations Shanghai(SH),Hangzhou(HZ),Kaihua(KH)and Xianju(XJ)and one wild population Yingshan(YS)of spotted barbell(Hemibarbus maculates)to assess their genetic diversity level and investigate the genetic structure of the populations.The dendrogram and STRUCTURE revealed that the populations XJ,KH,and HZ jointly formed one cluster,to which the populations SH and YS were sequentially adhered.The genetic diversity of the cultured populations maintained better,possible due to favourable hatchery conditions that decreased the effect of environmental selection present in wild populations.The results of the present study will contribute to the management of spotted barbell genetic resources,but also demonstrates how the genetic diversity of freshwater species is vulnerable to human activity.

Macro-evolutionary patterns of East Asian opsariichthyin-xenocyprinin-cultrin fishes related to the formation of river and river-lake environments under monsoon climate

Although the East Asian monsoon is believed to be an important driver for the origin and evolution of the biotas in this region,the association has rarely been rigorously tested.Here,using phylogenetic comparative methods and analyses of key innovations of adaptive traits,we investigated evolutionary patterns of the East Asian cyprinid opsariichthyin-xenocyprinin-cultrin clade;the dominant species in lakes and rivers,which are the typical productions of monsoon climate.Our molecular phylogenetic analyses revealed the relationships as(Opsariichthystribe t(((Oxygaster-tribe t Aphyocypris-tribe)t Metzia-tribe)t(Paralaubuca-tribe t(Squaliobarbus-tribe t(Hypophthalmichthys-tribe t(xenocyprinins t cultrins)))))).Based on Bayesian relaxed-clock methods,we found that origins of the Squaliobarbus-and Hypophthalmichthys-tribes bearing the key adaptation of riverine spawning with drifting eggs occurred 22.5 and 21.1 Mya,respectively.These times are consistent with the Early Miocene origin of major rivers(e.g.,Yangtze River)and the appearance of the East Asian monsoon climate.Diversification of the cultrins,characterized by spawning of adhesive eggs as well as swimming and feeding in lentic waters,were estimated to have evolved 16.6 to 0.2 Mya.This period covers three phases of enhancement of the East Asian monsoon from the Middle Miocene to the Pliocene(around 15–13,10–7,and 3.5 Mya).The habitats of these cultrins and their evolution also suggest the appearance and development of a lake-river environment during those periods.Therefore,our results suggest close relationships between the evolution of these fishes and geological events in East Asia.Further,they provide knowledge that may help facilitate future conservation strategies such as the maintenance of high river flows during dam construction and operation.