title: The effects of temperature and body size on immunological development and responsiveness in juvenile shortnose sturgeon (Acipenser brevirostrum).
abstract: Sturgeon are an important evolutionary taxa of which little is known regarding their responses to environmental factors. Water temperature strongly influences growth in fish; however, its effect on sturgeon immune responses is unknown. The objective of this study was to assess how 2 different temperatures affect immune responses in shortnose sturgeon (Acipenser brevirostrum) relevant immune organs such as the meningeal myeloid tissue, spleen, thymus and skin. These responses were studied in 2 different sizes of same age juvenile sturgeon kept at either 11 °C or 20 °C (4 treatment groups), before and after exposure to an ectoparasitic copepod (Dichelesthium oblongum). Based on a differential cell count, temperature was found to strongly influence immune cell production in the meningeal myeloid tissue, regardless of the fish sizes considered. Morphometric analysis of splenic white pulp showed a transient response to temperature. There were no differences between the groups in the morphometric analysis of thymus size. Splenic IRF-1 and IRF-2 had similar expression profiles, significantly higher in fish kept at 20 °C for the first 6 weeks of the study but not by 14 weeks. In the skin, IRF-1 was significantly higher in the fish kept at 11 °C over the first 6 weeks of the study. IRF-2 had a similar profile but there were no differences between the groups by the end of the trial. In conclusion, higher water temperatures (up to 20 °C) may have beneficial effects in maximizing growth and improving immunological capacity, regardless of the fish sizes considered in this study.
authors.affiliation: Department of Pathology and Microbiology, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island C1A 4P3, Canada. Electronic address: anamgradil@gmail.com.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Gradil
authors.affiliation: Department of Biomedical Sciences, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island C1A 4P3, Canada. Electronic address: gwright@upei.ca.
authors.forename: Glenda M
authors.initials: GM
authors.lastname: Wright
authors.affiliation: Department of Pathology and Microbiology, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island C1A 4P3, Canada.
authors.forename: David J
authors.initials: DJ
authors.lastname: Speare
authors.affiliation: Electron Microscopy Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island C1A 4P3, Canada. Electronic address: Wadowska@upei.ca.
authors.forename: Dorota W
authors.initials: DW
authors.lastname: Wadowska
authors.affiliation: Department of Pathology and Microbiology, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island C1A 4P3, Canada.
authors.forename: Sara
authors.initials: S
authors.lastname: Purcell
authors.affiliation: Department of Pathology and Microbiology, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island C1A 4P3, Canada. Electronic address: mfast@upei.ca.
authors.forename: Mark D
authors.initials: MD
authors.lastname: Fast
mesh_terms: D000818:Animals; D049628:Body Size / Q000276:immunology*; D033342:Copepoda / Q000502:physiology; D004478:Ectoparasitic Infestations / Q000235:genetics / Q000276:immunology / Q000662:veterinary*; D005260:Female; D005393:Fish Diseases / Q000235:genetics / Q000276:immunology*; D029941:Fish Proteins / Q000235:genetics* / Q000378:metabolism; D005399:Fishes / Q000033:anatomy & histology / Q000235:genetics / Q000254:growth & development; D005786:Gene Expression Regulation; D007107:Immune System / Q000033:anatomy & histology / Q000254:growth & development / Q000378:metabolism; D007113:Immunity, Innate; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D013696:Temperature
chemical_list: D029941:Fish Proteins
keywords: Immunity; Size; Sturgeon; Temperature