title: Abnormalities in sexual development of the amphipod Gammarus pulex (L.) found below  sewage treatment works.
abstract: Increasing numbers of widely used industrial, agricultural, and natural chemicals are known to elicit endocrine-disrupting effects in a wide range of vertebrate and invertebrate species. The objective of this study was to determine whether the sexual development of the freshwater crustacean Gammarus pulex (L.) was affected below sewage treatment works (STW) previously known to contain endocrine-disrupting chemicals in their effluent. The gonadal structure, external sexual characteristics, and size of gammarids from exposed sites were compared to those of gammarids from a reference site. No significant difference was found in the gonadal structure of males collected below two STW. However, a highly significant number of females collected from a site known to elicit high estrogenic responses in vertebrates displayed an abnormal structure of oocytes in vitellogenesis. Body size was significantly shorter and male/female size differential was significantly reduced below one of the STW. Analysis of gnathopod and genital papillae length data suggests that different allometric relationships of these organs to body size exist between sample sites.
authors.affiliation: School of Biological Sciences, University of London, Surrey, United Kingdom. grossm@environment-agency.gov.uk
authors.forename: M Y
authors.initials: MY
authors.lastname: Gross
authors.forename: D S
authors.initials: DS
authors.lastname: Maycock
authors.forename: M C
authors.initials: MC
authors.lastname: Thorndyke
authors.forename: D
authors.initials: D
authors.lastname: Morritt
authors.forename: M
authors.initials: M
authors.lastname: Crane
mesh_terms: D000818:Animals; D001824:Body Constitution; D003445:Crustacea / Q000254:growth & development*; D005260:Female; D005835:Genitalia / Q000002:abnormalities* / Q000033:anatomy & histology; D008297:Male; D010053:Ovary / Q000002:abnormalities; D012722:Sewage / Q000009:adverse effects*; D012737:Sex Factors; D014818:Vitellogenesis / Q000187:drug effects*; D014874:Water Pollutants, Chemical / Q000009:adverse effects*
chemical_list: D012722:Sewage; D014874:Water Pollutants, Chemical