title: Spatial variation in adult sex ratio across multiple scales in the invasive golden apple snail, Pomacea canaliculata.
abstract: Adult sex ratio (ASR) has critical effects on behavior and life history and has implications for population demography, including the invasiveness of introduced species. ASR exhibits immense variation in nature, yet the scale dependence of this variation is rarely analyzed. In this study, using the generalized multilevel models, we investigated the variation in ASR across multiple nested spatial scales and analyzed the underlying causes for an invasive species, the golden apple snail Pomacea canaliculata. We partitioned the variance in ASR to describe the variations at different scales and then included the explanatory variables at the individual and group levels to analyze the potential causes driving the variation in ASR. We firstly determined there is a significant female-biased ASR for this species when accounting for the spatial and temporal autocorrelations of sampling. We found that, counter to nearly equal distributed variation at plot, habitat and region levels, ASR showed little variation at the town level. Temperature and precipitation at the region level were significantly positively associated with ASR, whereas the individual weight, the density characteristic, and sampling time were not significant factors influencing ASR. Our study suggests that offspring sex ratio of this species may shape the general pattern of ASR in the population level while the environmental variables at the region level translate the unbiased offspring sex ratio to the female-biased ASR. Future research should consider the implications of climate warming on the female-biased ASR of this invasive species and thus on invasion pattern.
authors.affiliation: Pearl River Fisheries Research Institute Chinese Academy of Fishery Sciences/Key Laboratory of Tropical and Subtropical Fishery Resource Application and Cultivation Ministry of Agriculture Guangzhou 510380 China.
authors.forename: Meng
authors.initials: M
authors.lastname: Xu
authors.affiliation: Pearl River Fisheries Research Institute Chinese Academy of Fishery Sciences/Key Laboratory of Tropical and Subtropical Fishery Resource Application and Cultivation Ministry of Agriculture Guangzhou 510380 China; College of Fisheries and Life Science Shanghai Ocean University Shanghai 201306 China.
authors.forename: Miao
authors.initials: M
authors.lastname: Fang
authors.affiliation: Pearl River Fisheries Research Institute Chinese Academy of Fishery Sciences/Key Laboratory of Tropical and Subtropical Fishery Resource Application and Cultivation Ministry of Agriculture Guangzhou 510380 China.
authors.forename: Yexin
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Institute for Global Food Security School of Biological Sciences Queen's University Belfast MBC, 97 Lisburn Road Belfast BT9 7BL UK.
authors.forename: Jaimie T A
authors.initials: JT
authors.lastname: Dick
authors.affiliation: Pearl River Fisheries Research Institute Chinese Academy of Fishery Sciences/Key Laboratory of Tropical and Subtropical Fishery Resource Application and Cultivation Ministry of Agriculture Guangzhou 510380 China.
authors.forename: Hongmei
authors.initials: H
authors.lastname: Song
authors.affiliation: Pearl River Fisheries Research Institute Chinese Academy of Fishery Sciences/Key Laboratory of Tropical and Subtropical Fishery Resource Application and Cultivation Ministry of Agriculture Guangzhou 510380 China.
authors.forename: Du
authors.initials: D
authors.lastname: Luo
authors.affiliation: Pearl River Fisheries Research Institute Chinese Academy of Fishery Sciences/Key Laboratory of Tropical and Subtropical Fishery Resource Application and Cultivation Ministry of Agriculture Guangzhou 510380 China.
authors.forename: Xidong
authors.initials: X
authors.lastname: Mu
authors.affiliation: Pearl River Fisheries Research Institute Chinese Academy of Fishery Sciences/Key Laboratory of Tropical and Subtropical Fishery Resource Application and Cultivation Ministry of Agriculture Guangzhou 510380 China.
authors.forename: Dangen
authors.initials: D
authors.lastname: Gu
authors.affiliation: Pearl River Fisheries Research Institute Chinese Academy of Fishery Sciences/Key Laboratory of Tropical and Subtropical Fishery Resource Application and Cultivation Ministry of Agriculture Guangzhou 510380 China.
authors.forename: Jianren
authors.initials: J
authors.lastname: Luo
authors.affiliation: Pearl River Fisheries Research Institute Chinese Academy of Fishery Sciences/Key Laboratory of Tropical and Subtropical Fishery Resource Application and Cultivation Ministry of Agriculture Guangzhou 510380 China.
authors.forename: Yinchang
authors.initials: Y
authors.lastname: Hu
keywords: Adult sex ratio; Pomacea canaliculata; generalized multilevel model; nested spatial scales; variance components