title: Effects of Habitat Complexity on Pair-Housed Zebrafish.
abstract: Sexually mature zebrafish were housed as single male-female pairs with or without plastic vegetation for 1, 5, or 10 d for comparison of whole-body cortisol measured by radioimmunoassay. Individually housed male zebrafish were used as controls. In the fish that were pair-housed without vegetation (NVeg), one animal died in 5 of 24 pairs, and one animal was alive but wounded in an additional pair. No deaths or wounds occurred in the fish that were pair-housed with vegetation (Veg). Cortisol levels did not differ between the treatment groups on day 1. On day 5, cortisol values were higher in the Veg group than in the individually housed fish (P < 0.0005) and the NVeg fish (P = 0.004). On day 10, the relationships were inversed: cortisol levels had risen in the individually housed and NVeg groups and had fallen to baseline levels in the Veg group. Cortisol values on day 10 were lower in the Veg group than in the individually housed (P = 0.004) and NVeg (P = 0.05) groups. Cortisol levels in individually housed male zebrafish increased over time. Although this study did not demonstrate a reduction in cortisol levels associated with providing vegetation, this enrichment prevented injury and death from fighting. These findings show how commonly used housing situations may affect the wellbeing of laboratory zebrafish.
authors.affiliation: Departments of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA. vickie.keck@me.com.
authors.forename: Victoria A
authors.initials: VA
authors.lastname: Keck
authors.affiliation: Departments of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Dale S
authors.initials: DS
authors.lastname: Edgerton
authors.affiliation: Departments of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Hajizadeh
authors.affiliation: Departments of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Larry L
authors.initials: LL
authors.lastname: Swift
authors.affiliation: Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: William D
authors.initials: WD
authors.lastname: Dupont
authors.affiliation: Aquatic Resources Program, Boston Children's Hospital, Boston, Massachusetts, USA.
authors.forename: Christian
authors.initials: C
authors.lastname: Lawrence
authors.affiliation: Departments of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Kelli L
authors.initials: KL
authors.lastname: Boyd
mesh_terms: D000374:Aggression; D000818:Animals; D017753:Ecosystem; D005260:Female; D006799:Housing, Animal; D006854:Hydrocortisone / Q000032:analysis; D008297:Male; D015027:Zebrafish
chemical_list: D006854:Hydrocortisone