title: Water contaminated with Didymosphenia geminata generates changes in Salmo salar spermatozoa activation times.
abstract: Didimosphenia geminata ("didymo"), has become a powerful and devastating river plague in Chile. A system was developed in D. geminata channels with the purpose evaluating the effects of water polluted with didymo on the activation of Atlantic salmon (Salmo salar) spermatozoa. Results indicate that semen, when activated with uncontaminated river water had an average time of 60±21s. When using Powermilt, (a commercial activator), times of 240±21s are achieved, while rivers contaminated with D. geminata achieve a motility time of 30±12s. Interestingly enough, the kinetic parameters of VSL, VCL and VAP showed no significant changes under all of the conditions. Furthermore, the presence of D. geminata reduces activation time of the samples as the cells age, indicating increased effects in spermatozoa that are conserved for more than 5 days. D. geminata has antioxidant content, represented by polyphenols; 200ppm of polyphenol were obtained in this study per 10g of microalgae. Spermatozoa exposed to these extracts showed a reduction in mobility time in a dose dependent manner, showing an IC50 of 15ppm. The results suggest an effect on spermatozoa activation, possibly due to the release of polyphenols present in contaminated rivers, facilitating the alteration of sperm motility times, without affecting the viability or kinetics of the cells. These findings have important implications for current policy regarding the control of the algae. Current control measures focus on the number of visible species, and not on the compounds that they release, which this study shows, also have a problematic effect on salmon production.
authors.affiliation: Laboratorio Fisiología de la Reproducción, Escuela de Medicina Veterinaria, Núcleo de Investigación en Producción Alimentaria, Facultad de Recursos Naturales, Universidad Católica de Temuco, Chile.
authors.forename: Pamela
authors.initials: P
authors.lastname: Olivares
authors.affiliation: Laboratorio Fisiología de la Reproducción, Escuela de Medicina Veterinaria, Núcleo de Investigación en Producción Alimentaria, Facultad de Recursos Naturales, Universidad Católica de Temuco, Chile.
authors.forename: Paola
authors.initials: P
authors.lastname: Orellana
authors.affiliation: Laboratorio Fisiología de la Reproducción, Escuela de Medicina Veterinaria, Núcleo de Investigación en Producción Alimentaria, Facultad de Recursos Naturales, Universidad Católica de Temuco, Chile.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Guerra
authors.affiliation: Departamento de Ingeniería en Obras Civiles, Universidad de Santiago de Chile, Chile; Plataforma de Investigación en Ecohidrología y Ecohidráulica, EcoHyd Ltda, Chile.
authors.forename: Matías
authors.initials: M
authors.lastname: Peredo-Parada
authors.affiliation: Laboratorio de Investigación y Educación, Tonalli Ltda, Chile.
authors.forename: Viviana
authors.initials: V
authors.lastname: Chavez
authors.affiliation: Laboratorio de Criobiología y Análisis de Funcionalidad Espermática. Instituto de Ciencia Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Valdivia, Chile.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Ramirez
authors.affiliation: Laboratorio Fisiología de la Reproducción, Escuela de Medicina Veterinaria, Núcleo de Investigación en Producción Alimentaria, Facultad de Recursos Naturales, Universidad Católica de Temuco, Chile. Electronic address: jparodi@uct.cl.
authors.forename: Jorge
authors.initials: J
authors.lastname: Parodi
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology; D017377:Diatoms / Q000737:chemistry / Q000378:metabolism*; D005618:Fresh Water / Q000737:chemistry*; D008297:Male; D018613:Microscopy, Confocal; D059808:Polyphenols / Q000378:metabolism / Q000494:pharmacology; D045483:Rivers / Q000737:chemistry; D020317:Salmo salar / Q000502:physiology*; D013081:Sperm Motility / Q000187:drug effects / Q000502:physiology; D013094:Spermatozoa / Q000187:drug effects / Q000502:physiology*
chemical_list: D000975:Antioxidants; D059808:Polyphenols
keywords: Didymo; Sperm cells; Toxity