title: Changes in brain arginine vasotocin, isotocin, plasma 11-ketotestosterone and cortisol in round goby, Neogobius melanostomus, males subjected to overcrowding stress during the breeding season.
abstract: In natural spawning grounds, breeding round goby, Neogobius melanostomus, males are exposed to various social stimuli, including high density of same-sex competitors and separation from females. We hypothesize that breeding males subjected to overcrowding in the wild experience high stress that affects their socio-sexual behavior and their relationships among conspecifics. We designed an experiment to mimic natural stimulation when highly aggregated breeding males are subjected to same-sex opponents. Males were sampled sequentially from experimental tank stocked at decreasing fish densities of 15 fish/m(2), 9 fish/m(2) and 4 fish/m(2). We studied the effects of overcrowding on male behavior and selected hormones, brain arginine vasotocin (AVT) and isotocin (IT) and plasma 11-ketotestosterone (11-KT) and cortisol as these are known to play roles in reproduction and related social interactions. The highest brain AVT and plasma cortisol levels were measured in non-aggressive males kept in the overcrowded group of 15 fish/m(2). IT level was elevated in fish kept at the lower density of 9 fish/m(2), and at which the males began to display territoriality and aggression. The plasma level of 11-KT was similar in all the males. Brain AVT and IT and plasma cortisol along with behavioral observations can be applied as species-specific indicators of the well-being of round goby males.
authors.affiliation: Department of Genetics and Marine Biotechnology, Institute of Oceanology of the Polish Academy of Sciences, ul. Powstańców Warszawy 55, Sopot 81-712, Poland. ewasokol@iopan.gda.pl
authors.forename: Ewa
authors.initials: E
authors.lastname: Sokołowska
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Kleszczyńska
authors.forename: Hanna
authors.initials: H
authors.lastname: Kalamarz-Kubiak
authors.forename: Bartłomiej
authors.initials: B
authors.lastname: Arciszewski
authors.forename: Ewa
authors.initials: E
authors.lastname: Kulczykowska
mesh_terms: D000374:Aggression / Q000502:physiology; D000818:Animals; D001921:Brain / Q000378:metabolism*; D001947:Breeding; D005260:Female; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D010121:Oxytocin / Q000031:analogs & derivatives* / Q000378:metabolism; D010473:Perciformes / Q000097:blood / Q000378:metabolism / Q000502:physiology*; D012621:Seasons; D013312:Stress, Physiological / Q000502:physiology; D013731:Territoriality; D013739:Testosterone / Q000031:analogs & derivatives* / Q000097:blood; D013997:Time Factors; D014668:Vasotocin / Q000378:metabolism*
chemical_list: D013739:Testosterone; D010121:Oxytocin; C008215:isotocin; C003600:11-ketotestosterone; D014668:Vasotocin; D006854:Hydrocortisone