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Simple Summary Activation of immune cells is bioenergetically expensive, requiring precise control of cellular metabolism. This applies also to innate immune cells. The current study shows that the immunostimulants, Astragalus, Hyaluronic acid, Imiquimod, and Poly I:C can modulate the expression of genes involved in the innate antiviral immune, as well as genes associated with metabolism, in the early life stages of Atlantic salmon. Abstract Disease resistance of fish larvae may be improved by bath treatment in water containing immunostimulants. Pattern recognition receptors, such as TLR3, TLR7, and MDA5, work as an “early warning” to induce intracellular signaling and facilitate an antiviral response. A single bath of newly hatched larvae, with Astragalus, upregulated the expression of IFNα, IFNc, ISG15, MDA5, PKR, STAT1, TLR3, and TLR7 immune genes, on day 4 post treatment. Similar patterns were observed for Hyaluronic acid and Poly I:C. Increased expression was observed for ISG15, MDA5, MX, STAT1, TLR3, TLR7, and RSAD2, on day 9 for Imiquimod. Metabolic gene expression was stimulated on day 1 after immunostimulant bath in ULK1, MYC, SLC2A1, HIF1A, MTOR, and SIX1, in Astragalus, Hyaluronic acid, and Imiquimod. Expression of NOS2 in Poly I:C was an average fourfold above that of control at the same timepoint. Throughout the remaining sampling days (2, 4, 9, 16, 32, and 45 days post immunostimulant bath), NOS2 and IL1B were consistently overexpressed. In conclusion, the immunostimulants induced antiviral gene responses, indicating that a single bath at an early life stage could enable a more robust antiviral defense in fish. Additionally, it was demonstrated, based on gene expression data, that cell metabolism was perturbed, where several metabolic genes were co-regulated with innate antiviral genes.

El presente estudio se realizó con el objetivo de valorar dos dietas alternativas en la alimentación de alevines de Colossoma macropomum, utilizando como fuentes proteicas Leucaena leucocephala (Lam.), Machaerium sp y Glycine max (soya) como sustituto de la harina de pescado, comparándolo con una dieta testigo. Las dietas se formularon con un porcentaje teórico de proteína bruta de 30%. Los parámetros de crecimiento GPT, GTP%PI, TCE e ICD, no mostraron diferencia significativa entre dietas DLE y DM (p>0,05), mientras que IC, EA y CEP mostraron diferencias significativas (p0.05), whereas FGR, FE and PER showed significant differences between diets (p

El uso de prebióticos y probióticos en la nutrición animal produce efectos beneficiosos estimulando selectivamente el crecimiento o actividad de uno o más tipos de bacterias en los intestinos. El objetivo de la investigación buscó establecer las variaciones morfométrica microscópicas en intestino enriquecido con probióticos y prebióticos en alevines y juveniles de tilapia roja Oreochromis spp. Para ello se utilizaron 600 alevines y 600 juveniles, con 4 tratamientos y 3 repeticiones. Se realizó el análisis estadístico de medidas repetidas (PROC MIXED), utilizando el programa estadístico SAS, para las comparaciones múltiples se utilizó el test de Tukey. La variable altura de vellosidades en alevines y juveniles T 2 , T 3 y T 4 alcanzaron las mayores longitudes con un coeficiente de variación de 12,6% por lo que las medidas tienden a ser homogéneas, se demostró que la inclusión de estos compuestos, generan cambios significativos (P

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International audience; Based on the analysis of 12 egg and larval variables and temperature of 65 temperate freshwater fish species, the possible relationships between oocyte diameter, larval size at hatch, time and temperature were reassessed and the main early life-stage strategies were described and compared. Time and degree-days required to reach hatching and mixed feeding were weakly related to oocyte diameter and strongly to temperature. These results are chiefly because oocyte diameter and yolk reserves are weakly related and temperature strongly increases tissue differentiation rate, activity of hatching glands and embryo motility. Strong positive relationships were found between larval size and oocyte diameter and degree-days for incubation. No relationship was found between larval size and degree-days from hatching to mixed feeding and between degree-days for incubation and degree-days from hatching to mixed feeding. These last two results are chiefly because the developmental stages at hatching and at the onset of exogenous feeding are not fixed in ontogeny and are not directly related to either larval size or degree-days for incubation, but more probably are species specific. Whatever the spawning season, which can occur almost all year long, the different trade-offs at the early life-stages ensure that most larvae are first feeding during spring, when food size and abundance are the most appropriate.

The global mean temperature is predicted to increase by up to 5 °C during this century. For fish, being ectotherms, temperature is one of the most important environmental factors, influencing them in a number of different ways, including effects on physiological traits, timing of life history events and behavior. Atlantic salmon has been shown to grow faster after being incubated at warmer temperatures. One possible explanation for this could be that the increased incubation temperature causes decreased metabolic rates. The aim of this project was to examine whether this is true. Atlantic salmon eggs were incubated in three different temperature regimes: natural temperature conditions, heated water and a mixed temperature treatment, where eggs were incubated in increased temperature until the beginning of January and after that subjected to natural temperature conditions. Ventilation rate, a proxy for metabolism, was measured for fish from each treatment group, as well as fish length and weight. The results revealed significantly lower ventilation rates of the fish from the heated temperature treatment, but not of the fish from the mixed temperature treatment. This suggests that an increased incubation temperature causes lowered rates of metabolism in Atlantic salmon, and that the change occurs later than early January. Because of differences in size and life stage between fish from the different groups however, the results are uncertain and call for further investigations. A lowered metabolic rate will affect the fish’s behavior. A further development might therefore be to study fish survival in the wild in relation to a fish’s metabolic rate. Jordens medeltemperatur beräknas öka med upp till 5 °C det här århundradet. För fiskar, som är ektotermer, är temperatur en av de viktigaste abiotiska faktorerna och påverkar dem på en mängd olika sätt, bland annat genom förändring av fysiologiska attribut, tidpunkter för steg i livscykeln och beteende. Lax har visats växa snabbare efter att ha blivit inkuberade i varmare vattentemperatur. En möjlig förklaring till det kan vara att en förhöjd inkuberingstemperatur orsakar en lägre metabolism. Det här projektet syftade till att undersöka om så är fallet. Ägg från lax inkuberades i tre olika temperaturförhållanden: naturliga temperaturförhållanden, förhöjd temperatur och en blandad temperaturbehandling, där ägg inkuberades i förhöjd temperatur till början av januari, varefter de utsattes för naturliga temperaturförhållanden. Gälslagsfrekvens, som fungerar som en indikator för metabolism, mättes på fisk från varje behandlingsgrupp, samt fiskarnas längd och vikt. Resultaten visade signifikant lägre gälslagsfrekvenser hos fiskarna från behandlingen med förhöjd temperatur, men inte hos fiskarna från behandlingen med blandad temperatur. Detta indikerar att en förhöjd inkuberingstemperatur orsakar en lägre metabolism hos lax, och att förändringen sker senare än tidiga januari. På grund av skillnader i storlek och livsstadier hos fiskarna från de olika grupperna är resultaten dock osäkra, vilket gör att ytterligare studier behövs. En lägre ämnesomsättning påverkar fiskars beteende. En uppföljning kan därför vara att studera fiskars överlevnad i det vilda i relation till deras metabolism.

Parmi les facteurs abiotiques conditionnant la survie au cours de la vie embryonnaire et larvaire des poissons, le pH semble jouer un role primordial. La motivation de ce travail provient d'observations sur les importantes variations de ses valeurs au printemps, l'existence de pH tres acides en etangs forestiers et des mortalites importantes de brochetons au cours de la meme periode. L'experimentation s'est deroulee en aquariums avec une gamme de valeurs allant de 4,5 a 10,5 unites pH. Des tests en bains, continus ou momentanes (1 heure), sont effectues. Deux stades sont etudies : les oeufs fecondes suivis jusqu'apres l'eclosion ; les alevins incubes a pH neutre suivis jusqu'a la resorption de la vesicule vitelline. Les parametres suivants sont etudies : survie, deroulement de l'embryogenese, anomalies eventuelles, performances de nage. Le rythme cardiaque de l'embryon a ete mesure. Les resultats sont les suivants : - Les valeurs letales sont respectivement de 6 et 10 (alevins) et 4,5 et 10,5 (embryons). - L'action sur les oeufs est moins forte, meme si une mortalite importante (46,7 %) et de faibles performances de nage pour un pH inferieur a 6 semblent hypothequer la reussite du recrutement. La valeur de 10,5 provoque un developpement deficient des quelques individus survivants. - Sur les alevins, meme en bains d'une heure, la survie est faible : 42,6 % a pH 5, 29,3 % a pH 10. Le rythme cardiaque ne variait pas de facon notable entre les seuils de tolerance. Ces resultats permettent de recapituler pour une espece largement distribuee les conditions de recrutement liees a l'acidite du milieu. Il faut noter que les hausses brutales du pH au printemps dans des plans d'eau sur substrat cristallin rendent aleatoires la reussite des empoissonnements en brochetons des premiers stades.

El propósito de este trabajo fue determinar el óptimo proteico en la alimentación de alevines de coporo (Prochidolus mariae). Se formularon 4 dietas con niveles crecientes de proteína cruda (15, 25, 35 y 45%), y valores energéticos similares entre 19,6 y 20,4 KJ g-1, de manera que sean isocalóricas. Se realizaron tres repeticiones por cada dieta (n=3). Los alevines fueron aclimatados y alimentados con una dieta comercial durante una semana y luego de este tiempo se le suministraron las dietas a ensayar ad libitum tres veces al día durante 41 días. Se colocaron 55 alevines por pecera con peso medio inicial de 0,32g ± 0,04. Se llevó un registro durante tres períodos, de catorce días cada uno, al final de cada período se determinó la ganancia de peso (GP) y el consumo de alimento por pecera. Los parámetros zootécnicos, pesos medios finales (PMF), ganancia total de peso (GTP), tasa de crecimiento específico (TCE) e índice de crecimiento diario (ICD) de los peces, no presentaron diferencias significativas entre las dietas con 35 y 45% de proteínas, lo que indica que una dieta con 35% de proteínas, es adecuada para un buen desarrollo del pez en este estadio. The purpose of this work was to determine the optimal protein level to feed alevins of coporo (Prochidolus mariae) fish. Four diets were formulated with growing levels of crude protein (15, 25, 35 and 45%) with similar energy values (between 19,6 and 20,4 KJ g-1). Three trials were performed for each diet. The animals were acclimated and fed a commercial diet during one week and after that time the test diets were administered ad libitum three times a day during 41 days. Fifty five frys per fishbowl were placed with an initial mean weight of 0,32 ± 0,04 g. Three periods of fourteen days each were registered and at the end of each period weight gain (GP) and food consumption per fish tank was determined. The zootechnical parameters, final mean weights (PMF), total weight gain (GTP), specific growth rate (TCE) and daily growth index (ICD) of the fish did not show significant differences between the diets with protein levels of 35% and 45% proteins, indicating that a diet with 35% protein is adequate for a good development of the fish in this stage.

El presente estudio se realizó con el objetivo de valorar dos dietas alternativas en la alimentación de alevines de cachama negra (Colossoma macropomum), utilizando como fuentes proteicas harinas de lombriz (Eisenia foetida), soya (Glycine max) y caraotas (Phaseolus vulgaris) como sustituto de la harina de pescado, comparándolo con una dieta testigo. Las dietas se formularon con un porcentaje teórico de proteína bruta de 32%. En cuanto a la composición corporal de las cachamas alimentadas con las dietas, el % de proteína se determinó entre 47,3 y 48,6 y % de lípidos entre 21,2 y 24,3; sin presentar diferencias significativas (p>0,05). De acuerdo a los resultados se puede concluir que una sustitución total de la harina de pescado por harina de soya- lombriz, y de soya-caraota conduciría a buenos resultados para la alimentación de alevines de cachama negra. The current study was carried out with the purpose of evaluating two alternative diets in the feeding of Colossoma macropomum alevins using earthworm flour (Eisenia foetida), soybean (Glycine max) and beans (Phaseolus vulgaris) as the protein source and as fishmeal substitute and was compared with a control diet. The diets were formulated with a crude protein with a theoretical 32% protein. The body composition of C. macropomum fed the different diets showed that protein was between 47,3%% and 48,6% and the lipid content was found between 21,2% and24,3% not showing significant differences between diets (p>0,05). According to the results obtained there is a reason to think that a total substitution of fishmeal by earthworm meal, soybean and beans would be successful in feeding C. macropomum alevins.

Contenu du chapitre : Variabilité des caractéristiques du recrutement estuarien - Recrutement fluvial et phase de colonisation du bassin versant - Phases de sédentarisation plus ou moins précoces et longues - Métamorphose en anguille argentée et dévalaison

International audience; The common evergreen dwarf shrub Empetrum hermaphroditum has influence on the functioning of boreal terrestrial ecosystems in northern Sweden. The negative effects of E. hermaphroditum are partly attributed to the production of the dihydrostilbene, batatasin-III, which is released from leaves and litter by rain and snowmelt. In this study, we investigated whether batatasin-III is carried by runoff into streams and lakes during the snowmelt period and whether it is also potentially hazardous to aquatic fauna. Sampling of water from streams and a lake for which the surrounding terrestrial vegetation is dominated by E. hermaphroditum was done during the snowmelt period in May 1993 and in 1998, and analyzed for batatasin-III. Using 24- and 48-hr standard toxicity tests, we analyzed toxicity to brown trout ( Salmo trutta) alevins and juvenile water fleas ( Daphnia magna). Toxicity ( proportion of dead individuals) to trout was tested at pH 6.5 and compared with that of a phenol within a range of concentrations. In the toxicity ( proportion of immobilized individuals) test on D. magna, the interactive effect of pH ( pH 5.5 - 7.0) was included. Concentration of batatasin-III was generally higher in 1998 than in 1993 and showed peak levels during snowmelt. Concentration in ephemeral runnels > the lake > streams running through clear-cuts dominated by E. hermaphroditum > control streams lacking adjacent E. hermaphroditum vegetation. The maximum concentration of batatasin-III found was 1.06 mg l(-1). The proportion of dead yolk sac alevins increased significantly (P < 0.001) with increasing concentrations of batatasin-III and time of exposure. After 24 hr, EC50 was 10 mg l(-1). It was 2 mg l(-1) after 48 hr. The effect of phenol was negligible, indicating a specific phytotoxic effect of the bibenzyl structure of batatasin-III. The proportion of mobile D. magna became significantly smaller ( P < 0: 001) with increasing concentrations of batatasin-III, with decreasing pH, and with increasing exposure time. EC50 varied between 7 and 17 mg l(-1) at pH 5.5 and 7.0, respectively. After 24 hr EC50 decreased and was 2.5 at pH 5.5 and 12 mg l(-1) at pH 7.0. The levels of batatasin-III found in the field samples were below the lowest EC50 in acute toxicity tests. However, in view of the interactive effect of pH and exposure time, this study suggests that this stable plant metabolite may impose a lethal effect on the aquatic fauna in small streams.

Not available; Les techniques aquariologiques simples utilisées à l'aquarium tropical de Nancy et appliquées à l'aquaculture, sont testées dans le cadre d'une production d'alevins de truite arc-en-ciel, Oncorhynchus mykiss w., de 1 g en eau recyclée (18-20°C). Leur adaptation aux exigences d'un élevage intensif et à la réalisation d'un prototype de bassin d'alevinage (1,8 m³) ne présente aucune difficulté majeure. À partir de larves d'un poids moyen initial de 0,12-0,19 g et d'une densité à l'empoissonnement de 12 000 à 15 000 individus par bassin, cet équipement, fonctionnant en circuit fermé total, permet la production en 28 jours et avec un taux de survie supérieur à 90%, d'alevins de 1 g d'un état sanitaire irréprochable. Des taux moyens de croissance favorables (22,8 mg/j/ind. pour la phase alevin de 0,12-0,5 g) et des indices de conversion alimentaire compris entre 0,70 et 0,74, proches des valeurs standards (0,69) sont obtenus à l'aide d'un aliment pressé traditionnel. L'utilisation d'un aliment à plus haute valeur énergétique enrichi en lipides (4%) et appauvri en protéines (6%) assure une amélioration de ces performances et réduit les rejets azotés inorganiques. Les insuffisances de la filtration biologique entrainent une accumulation de substances azotées inorganiques toxiques, principal facteur limitant de la capacité de production de l'équipement proposé. Une brusque élévation des teneurs en nitrites fixe la charge piscicole maximale admissible à 15-16 kg/bassin et la capacité de production à 200 kg/an

Not available, Les techniques aquariologiques simples utilisées à l'aquarium tropical de Nancy et appliquées à l'aquaculture, sont testées dans le cadre d'une production d'alevins de truite arc-en-ciel, Oncorhynchus mykiss w., de 1 g en eau recyclée (18-20°C). Leur adaptation aux exigences d'un élevage intensif et à la réalisation d'un prototype de bassin d'alevinage (1,8 m³) ne présente aucune difficulté majeure. À partir de larves d'un poids moyen initial de 0,12-0,19 g et d'une densité à l'empoissonnement de 12 000 à 15 000 individus par bassin, cet équipement, fonctionnant en circuit fermé total, permet la production en 28 jours et avec un taux de survie supérieur à 90%, d'alevins de 1 g d'un état sanitaire irréprochable. Des taux moyens de croissance favorables (22,8 mg/j/ind. pour la phase alevin de 0,12-0,5 g) et des indices de conversion alimentaire compris entre 0,70 et 0,74, proches des valeurs standards (0,69) sont obtenus à l'aide d'un aliment pressé traditionnel. L'utilisation d'un aliment à plus haute valeur énergétique enrichi en lipides (4%) et appauvri en protéines (6%) assure une amélioration de ces performances et réduit les rejets azotés inorganiques. Les insuffisances de la filtration biologique entrainent une accumulation de substances azotées inorganiques toxiques, principal facteur limitant de la capacité de production de l'équipement proposé. Une brusque élévation des teneurs en nitrites fixe la charge piscicole maximale admissible à 15-16 kg/bassin et la capacité de production à 200 kg/an

The diet composition of 41 0+ brown trout (Salmo trutta L., 1758) (33-97 mm TL) captured in August 2002 in the Erro River (North of Spain) is described. The diet was mainly composed by aquatic invertebrates. Excluding nematodes because they are possible parasites, the most consumed prey items were mayflies, dipterans, and crustaceans. Fingerling brown trout refused Chironomidae, Elmidae, and terrestrial invertebrates from the drift, and Elmidae, Heptageniidae, and Leuctridae from the benthos, while they showed preference for Rhyacophilidae from the benthos. Fingerling brown trout seems to act as an opportunistic predator, and the consumption of different preys seems to be influenced by their accessibility, predation risk, and their energetic value. Se analizó la dieta de 41 alevines de trucha común (Salmo trutta L., 1758) (33-97 mm LT) del río Erro (Norte de España). Su alimentación estuvo constituida principalmente por invertebrados acuáticos. Si no se tiene en cuenta a los nematodos por la posibilidad de tratarse de parásitos, las presas más consumidas fueron efémeras, dípteros y crustáceos. Los alevines de trucha común rechazaron los quironómidos, élmidos y los invertebrados terrestres de la deriva, así como los élmidos, heptagénidos y leúctridos del bentos, mientras que mostraron preferencia por los riacofílidos del bentos. Los alevines de trucha común parecen comportarse como depredadores oportunistas, pareciendo estar el consumo de las diferentes presas influenciado por su accesibilidad, el riesgo de predación y el valor energético de cada presa.