title: Sex Determination in Bluegill Sunfish Lepomis macrochirus: Effect of Temperature on Sex Ratio of Four Geographic Strains.
abstract: There is increasing evidence that temperature effects on sex ratio in fish species are ubiquitous. Temperature effects on sex ratio could be influenced by parent, strain, and population, whether in fish species with temperature-dependent sex determination or genetic sex determination plus temperature effects. In the present study, effects of genotype-temperature interactions on sex determination in bluegill sunfish were further investigated, based on our previous results, using four geographic strains: Hebron, Jones, Hocking, and Missouri. In the Hebron strain, the two higher-temperature treatment groups (24 °C and 32 °C) produced more males than the low-temperature treatment group (17 °C) from 6 days post-hatching (dph) to 90 dph. In contrast, the low-temperature treatment produced more males than the other two higher-temperature treatments in the Jones strain. No significant effects of temperature on sex ratio were detected in the other two strains. Our results from sex ratio variance in different treatment times suggest that the thermosensitive period of sex differentiation occurs prior to 40 dph. Our results further confirmed that genotype-temperature interactions influence sex determination in bluegill. Therefore, to significantly increase the proportion of males, which grow faster and larger than females, a consumer- and environment-friendly approach may be achieved through selection of temperature sensitivity in bluegill.
authors.affiliation: Aquaculture Genetics and Breeding Laboratory, The Ohio State University South Centers, 1864 Shyville Road, Piketon, Ohio, 45661.
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Shen
authors.affiliation: Aquaculture Genetics and Breeding Laboratory, The Ohio State University South Centers, 1864 Shyville Road, Piketon, Ohio, 45661 wang.900@osu.edu.
authors.forename: Han-Ping
authors.initials: HP
authors.lastname: Wang
authors.affiliation: Aquaculture Genetics and Breeding Laboratory, The Ohio State University South Centers, 1864 Shyville Road, Piketon, Ohio, 45661.
authors.forename: Hong
authors.initials: H
authors.lastname: Yao
authors.affiliation: Aquaculture Genetics and Breeding Laboratory, The Ohio State University South Centers, 1864 Shyville Road, Piketon, Ohio, 45661.
authors.forename: Paul
authors.initials: P
authors.lastname: O'Bryant
authors.affiliation: Aquaculture Genetics and Breeding Laboratory, The Ohio State University South Centers, 1864 Shyville Road, Piketon, Ohio, 45661.
authors.forename: Dean
authors.initials: D
authors.lastname: Rapp
authors.affiliation: Aquaculture Genetics and Breeding Laboratory, The Ohio State University South Centers, 1864 Shyville Road, Piketon, Ohio, 45661.
authors.forename: Kun-Qian
authors.initials: KQ
authors.lastname: Zhu
mesh_terms: D000818:Animals; D005260:Female; D005399:Fishes / Q000502:physiology*; D005838:Genotype; D008297:Male; D010473:Perciformes / Q000502:physiology*; D019849:Sex Determination Processes / Q000502:physiology; D012744:Sex Ratio; D013045:Species Specificity; D013696:Temperature