caa a22 4500 445892145 CHVBK 20180317145620.0 cr unu---uuuuu 170323e20110801xx s 000 0 eng 10.1007/s10750-011-0701-9 doi (NATIONALLICENCE)springer-10.1007/s10750-011-0701-9 Occupation, body size and sex ratio of round goby ( Neogobius melanostomus ) in established and newly invaded areas of an Ontario river [Elektronische Daten] [Lee Gutowsky, Michael Fox] Invasive species represent a challenge because the particular characteristics of a species' invasion are often unknown before the invasion. To provide some clarity as to how invasive species demographic structure might change as a population advances its range, we compared the proportion of occupied sites, size structure and sex ratio of round gobies in the area where they first invaded with more recently invaded areas at the extent of their range in a river in south-eastern Ontario. We used a standardized angling technique to sample gobies larger than 45-mm total length in the summer and early autumn of 2007. Round goby at the upstream and downstream extent of their range occupied a lower proportion of randomly selected sites, and contained a wider distribution of sizes as well as significantly larger individuals. Sex ratios in all areas were male-biased and the male-to-female ratio was significantly higher in the upstream segment of the river (2.2:1) compared to the area of first introduction (1.4:1). The difference between the newly invaded and the established sites suggests that round goby population structure may be affected by density. The results of this study help us further describe the demographic characteristics of biological invasions whilst examples of population structure and behaviour in gobies and other species provide a basis for generating hypotheses for range expansion. Springer Science+Business Media B.V., 2011 Dispersal nationallicence Gobiidae nationallicence Invasive nationallicence Non-indigenous nationallicence Range expansion nationallicence Gutowsky Lee Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, K1S 5B6, Ottawa, ON, Canada aut Fox Michael Environmental and Resource Studies Program and Department of Biology, Trent University, 1600 West Bank Drive, K9J 7B8, Peterborough, ON, Canada aut Hydrobiologia Springer Netherlands 671/1(2011-08-01), 27-37 0018-8158 671:1<27 2011 671 10750 https://doi.org/10.1007/s10750-011-0701-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10750-011-0701-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Gutowsky Lee Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Carleton University, K1S 5B6, Ottawa, ON, Canada aut NATIONALLICENCE 700 1- Fox Michael Environmental and Resource Studies Program and Department of Biology, Trent University, 1600 West Bank Drive, K9J 7B8, Peterborough, ON, Canada aut NATIONALLICENCE 773 0- Hydrobiologia Springer Netherlands 671/1(2011-08-01), 27-37 0018-8158 671:1<27 2011 671 10750 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer