Vitaminas A y E en la dieta maternal y su influencia en la calidad del huevo y el desarrollo embrionario en peces: una revisión

Early development in fish is dependent on essential nutrients present in the egg. Vitamins E and A are critical to the normal development of fish embryos. Vitamin E functions primarily as an antioxidant to protect unsaturated lipids from oxidative degradation. Vitamin A or its provitamin carotenoid forms support growth, are required for the differentiation and maintenance of epithelial tissue and can be converted to forms of the vitamin that are potent morphogens. Fish cannot synthesise either of the vitamins, so the maternal dietary content of each prior to oogenesis is an important determinant of reproductive fitness. Here we review the basic metabolism of vitamins E and A and carotenoids and their processing from the maternal diet and deposition into eggs. Evidence for the link between levels of each of the vitamins in eggs and measures of reproductive fitness are also discussed.El desarrollo embrionario en peces es dependiente de los nutrientes esenciales presentes en el huevo. Las vitaminas E y A son críticas en el desarrollo normal de los embriones de los peces. La vitamina E funciona sobre todo como un antioxidante para proteger los lípidos no saturados contra la degradación oxidativa. La vitamina A, o los carotenoides formas de provitamina, se requieren para la diferenciación y el mantenimiento del tejido fino epitelial y se puede convertir a las formas de la vitamina que son morfogenes potentes. Los peces tampoco pueden sintetizar las vitaminas, de modo que el contenido dietético materno de cada una antes de la oogenesis es un determinante importante de la aptitud reproductiva. Aquí repasamos el metabolismo básico de las vitaminas E y A y los carotenoides y su procesamiento desde la dieta materna a la deposición en los huevos. Se discute también la evidencia del acoplamiento entre los niveles de cada una de las vitaminas en los huevos y las medidas de aptitud reproductiva en los adultos

Thyroid hormones correlate with resting metabolic rate, not daily energy expenditure, in two charadriiform seabirds

K. Woo, M. Le Vaillant, T. van Nus, and especially A. Wesphal, J. Schultner and I. Dorresteijn, assisted with field work, often under unpleasant conditions. K. Wauthier was instrumental in wrestling the gamma counter into submission. P. Redman and C. Hambly conducted the isotopic analyses. K. Scott and K. Campbell provided the FoxBox. K.H.E. benefited from a Natural Sciences and Engineering Research Council (NSERC) Vanier Scholarship, Association of Canadian Universities for Northern Studies Garfield Weston Northern Studies Award and the Arctic Institute of North America Jennifer Robinson Scholarship. Research support came from Bird Studies Canada/Society of Canadian Ornithologists James Baillie Award, Animal Behavior Society Research Grant, American Ornithologists’ Union Research Grant, Frank Chapman Research Grant, the Waterbird Society Nisbet Grant and NSERC Discovery Grants to J.F.H. and W.G.A. Any use of trade names is for descriptive purposes only and does not imply endorsement by the US Government.Peer reviewedPublisher PD

Microplastics in aquatic environments: Implications for Canadian ecosystems

AbstractMicroplastics have been increasingly detected and quantified in marine and freshwater environments, and there are growing concerns about potential effects in biota. A literature review was conducted to summarize the current state of knowledge of microplastics in Canadian aquatic environments; specifically, the sources, environmental fate, behaviour, abundance, and toxicological effects in aquatic organisms. While we found that research and publications on these topics have increased dramatically since 2010, relatively few studies have assessed the presence, fate, and effects of microplastics in Canadian water bodies. We suggest that efforts to determine aquatic receptors at greatest risk of detrimental effects due to microplastic exposure, and their associated contaminants, are particularly warranted. There is also a need to address the gaps identified, with a particular focus on the species and conditions found in Canadian aquatic systems. These gaps include characterization of the presence of microplastics in Canadian freshwater ecosystems, identifying key sources of microplastics to these systems, and evaluating the presence of microplastics in Arctic waters and biota

Freshwater connectivity transforms spatially integrated signals of biodiversity

Aquatic ecosystems offer a continuum of water flow from headwater streams to inland lakes and coastal marine systems. This spatial connectivity influences the structure, function and dynamics of aquatic communities, which are among the most threatened and degraded on earth. Here, we determine the spatial resolution of eDNA in dendritic freshwater networks, which we use as a model for connected metacommunities. Our intensive sampling campaign comprised over 430 eDNA samples across 21 connected lakes, allowing us to analyse detections at a variety of scales, from different habitats within a lake to entire lake networks. We found strong signals of within-lake variation in eDNA distribution reflective of typical habitat use by both fish and zooplankton. Most importantly, we also found that connecting channels between lakes resulted in an accumulation of downstream eDNA detections in lakes with a higher number of inflows, and as networks increased in length. Environmental DNA achieves biodiversity surveys in these habitats in a high-throughput, spatially integrated way. These findings have profound implications for the interpretation of eDNA detections in aquatic ecosystems in global-scale biodiversity monitoring observations.Raw sequence files are .gz format; can be opened with WinZip or similar. R and R studio for opening statistical analysis scriptsFunding provided by: Canada Research ChairsCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100001804Award Number: 230517Funding provided by: Canada Research ChairsCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100001804Award Number: 237170Funding provided by: MitacsCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100004489Award Number: IT08003Funding provided by: Quebec Centre for Biodiversity Science *Crossref Funder Registry ID: Award Number: Funding provided by: WSP Montreal Environment Department *Crossref Funder Registry ID: Award Number: Funding provided by: Natural Sciences and Engineering Research Council of CanadaCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100000038Award Number: 2016-04016Funding provided by: Natural Sciences and Engineering Research Council of CanadaCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100000038Award Number: 04331-201

Internal wave turbulence driven by tides

Poster presented at Euromech-Ercoftac conference <i>Turbulent Cascades II.</i> <br

Investigating Endocrine and Physiological Parameters of Captive American Kestrels Exposed by Diet to Selected Organophosphate Flame Retardants

Organophosphate triesters are high production volume additive flame retardants (OPFRs) and plasticizers. Shown to accumulate in abiotic and biotic environmental compartments, little is known about the risks they pose. Captive adult male American kestrels (Falco sparverius) were fed the same dose (22 ng OPFR/g kestrel/d) daily (21 d) of tris(2- butoxyethyl) phosphate (TBOEP), tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP), or tris(1,2-dichloro-2-propyl) phosphate (TDCIPP). Concentrations were undetected in tissues (renal, hepatic), suggesting rapid metabolism. There were no changes in glutathione status, indicators of hepatic oxidative status, or the cholinergic system (i.e., cerebrum, plasma cholinesterases; cerebrum muscarinic, nicotinic receptors). Modest changes occurred in hepatocyte integrity and function (clinical chemistry). Significant effects on plasma free triiodothyronine (FT3) concentrations occurred with exposure to TBOEP, TCEP, TCIPP, and TDCIPP; TBOEP and TCEP had additional overall effects on free thyroxine (FT4), whereas TDCIPP also influenced total thyroxine (TT4). Relative increases (32%−96%) in circulating FT3, TT3, FT4, and/or TT4 were variable with each OPFR at 7 d exposure, but limited thereafter, which was likely maintained through decreased thyroid gland activity and increased hepatic deiodinase activity. The observed physiological and endocrine effects occurred at environmentally relevant concentrations and suggest parent OPFRs or metabolites may have been present despite rapid degradation

Capacidad reproductiva de la trucha de lago (Salvelinus namaycush) expuesta a concentraciones ambientales relevantes del potente estrógeno etilestradiol (EEZ) en un experimento de exposición en un lago

The synthetic estrogen, ethynylestradiol (EE2), has been identified in many aquatic environments. EE2 induces biochemical and physiological effects in exposed fish, but linkages to widespread reproductive dysfunction in populations have not been established. Mortality in early life stages has only been documented at relatively high concentrations, above those found in the environment. To examine the potential effects of environmentally relevant concentrations of EE2, reproductive endpoints were examined in lake trout (Salvelinus namaycush) captured from a lake experimentally treated with ~5 ng/L EE2. Monitoring began two years prior to EE2 additions in the lake and for 3 years of additions. A nearby lake in which no EE2 was added was used as a reference. Eggs from fish in each lake were fertilised with milt from the same fish stocks. Fertilization and hatch, mortality, deformities, and size of the fry at swim up were not negatively affected by EE2 exposure. While our earlier studies have reported impaired reproductive success in small-bodied fish exposed to EE2 in the same system, lake trout appear to be less affected at the biochemical level and no impacts were determined in other reproductive and population level impacts.El estr&oacute;geno sint&eacute;tico, etinilestradiol (EE2), ha sido encontrado en varios sistemas acu&aacute;ticos. Se ha demostrado que los peces expuestos a este compuesto sufren cambios bioqu&iacute;micos y fisiol&oacute;gicos, pero el impacto en las funciones reproductivas de las poblaciones no ha sido examinado. Para examinar el efecto de concentraciones relevantes del EE2, examinamos los marcadores reproductivos en la trucha de lago (Salvelinus namaycush) expuesta a ~ 5 ng/L EE2. El EE2 fue adicionado a un lago cuyo monitoreo se llevo a cabo 2 a&ntilde;os antes y tres a&ntilde;os despu&eacute;s de la adici&oacute;n del compuesto. Un lago sin contaminar fue utilizado como referencia. Huevos obtenidos de las truchas de ambos lagos fueron fertilizados con semen de machos del lago correspondiente. Los porcentajes de fertilizaci&oacute;n, eclosi&oacute;n, mortalidad y deformidades, as&iacute; como la talla de los alevines no fueron afectados por la exposici&oacute;n al EE2. Anteriormente, en este mismo lago, hab&iacute;amos demostrado que el &eacute;xito reproductivo en los peces de peque&ntilde;a talla estaba significativamente afectado, sin embargo la trucha de lago no parece ser afectada a nivel bioqu&iacute;mico y no se produjeron impactos, en t&eacute;rminos reproductivos o a nivel de poblaciones

Quantifying Elements in Arctic Grayling and Bull Trout in the South Nahanni River Watershed, Northwest Territories, Using Nonlethal Tissue Samples

<p>Monitoring of contaminants in fish generally involves lethal sampling, but public scrutiny and increased pressure on fisheries have driven the need to develop nonlethal sampling methods. We examined the ability of adipose, anal, and caudal fin tissues to serve as nonlethal surrogates for lethal muscle tissue samples in the analysis of metals (elements). First, we evaluated the use of biopsies by examining relationships between concentrations of 39 elements in low-volume dorsal muscle biopsies and high-volume muscle samples from Arctic Grayling <i>Thymallus arcticus</i> and Bull Trout <i>Salvelinus confluentus</i> collected in the South Nahanni River watershed, Northwest Territories, Canada. Low-volume dorsal biopsy samples in this study served to most closely model the concentrations of elements found in high-volume dorsal samples; caudal and anal fins were more representative of high-volume dorsal samples than were adipose fins. Regressions between high- and low-volume dorsal muscle samples were significant for 12 elements/species, with Cs, Rb, and Tl having the strongest relationships in both species. Regression analyses comparing low-volume muscle samples and fin samples revealed variation between Arctic Grayling and Bull Trout, but Co, Hg, and Tl concentrations among samples were strongly related for both species. Addition of fish length or age as a covariate did not greatly improve the predictive power of calculated regressions. For future monitoring, selection of a nonlethal sampling strategy (e.g., use of dorsal biopsy or adipose fin samples) will require consideration of the element of interest, the primary route of exposure, interaction with other elements, and the basic biology and ecology of the fish species. Ideally, nonlethal sampling tools can be further developed for the two species to promote inclusion of community partners; these tools offer sustainable, long-term approaches for monitoring sensitive fish populations in northern Canadian habitats.</p> <p>Received February 29, 2016; accepted September 9, 2016Published online December 20, 2016</p