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Ian D Whittington - One of the best experts on this subject based on the ideXlab platform.
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egg laying patterns and in vivo egg production in the monogenean parasites heteraxine heterocerca and benedenia Seriolae from japanese yellowtail Seriola quinqueradiata
Parasitology, 2008Co-Authors: A J Mooney, I Ernst, Ian D WhittingtonAbstract:Egg-laying patterns and egg production in Heteraxine heterocerca from the gills and Benedenia Seriolae from the skin of Japanese yellowtail Seriola quinqueradiata in Japan were investigated in vivo . Eggs were collected every 3 h from sexually mature H. heterocerca and B. Seriolae infecting 3 S. quinqueradiata kept individually over 3 consecutive days and exposed to alternating periods of illumination and darkness (LD 12:12; light on 06.00, light off 18.00) and maintained at 23·8±0·1°C and 35 ppt salinity. A well-defined egg-laying rhythm was demonstrated for H. heterocerca while B. Seriolae was shown to release eggs continuously. A total of 114 000 H. heterocerca eggs was collected and of these, 45·4 (42·5–49·9)% were collected during the first 3 h period following dark at 18.00 h. A total of 662 857 B. Seriolae eggs was collected and these were distributed over each 3 h period ranging from 11·1 to 14·1% of the daily egg output. All eggs extracted from the uterus of each H. heterocerca were joined together forming an ‘egg-string’. The contrasting egg-laying patterns of H. heterocerca and B. Seriolae suggest that each species makes use of a different infection strategy to infect the same host species, S. quinqueradiata .
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efficacy of orally administered praziquantel against zeuxapta Seriolae and benedenia Seriolae monogenea in yellowtail kingfish Seriola lalandi
Diseases of Aquatic Organisms, 2007Co-Authors: Rissa E Williams, Ingo Ernst, Clinton B Chambers, Ian D WhittingtonAbstract:We investigated the efficacy of praziquantel (PZQ) administered orally to yellowtail kingfish (Seriola lalandi in sea-cage aquaculture in South Australia) against the monogeneans Zeuxapta Seriolae and Benedenia Seriolae infesting gills and skin, respectively. PZQ was adminis- tered to fish by surface-coating feed pellets (Trial 1) or by direct intubation of the stomach (Trial 2). In both trials 4 daily doses were administered: 50 and 75 mg kg -1 body weight (BW) d -1 for 6 d, and 100 and 150 mg kg -1 BW d -1 for 3 d. Mean parasite intensity was compared between medicated fish and unmedicated control fish. In Trial 1, fish fed lower daily doses of PZQ for 6 d (50 and 75 mg kg -1 BW d -1 ) had fewer Z. Seriolae and B. Seriolae than fish fed higher daily doses for 3 d (100 and 150 mg kg -1 BW d -1 ). Fish rejected feed pellets surface-coated with PZQ, suggesting PZQ affected palatability of feed, and may explain differences in efficacy between treatments. In Trial 2, where PZQ was admin- istered by intubation, there were fewer Z. Seriolae and B. Seriolae in medicated fish than control fish. Intubated PZQ was also effective against newly recruited Z. Seriolae and B. Seriolae. PZQ could be developed as a useful treatment for Z. Seriolae and B. Seriolae parasitising S. lalandi in sea-cage aquaculture if suspected palatability problems are resolved.
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risk assessment for metazoan parasites of yellowtail kingfish Seriola lalandi perciformes carangidae in south australian sea cage aquaculture
Aquaculture, 2007Co-Authors: Kate S Hutson, I Ernst, Ian D WhittingtonAbstract:Metazoan parasites can threaten the sustainability and profitability of finfish sea-cage aquaculture. It is critical, therefore, to identify local parasite species and determine which are potentially harmful. Although several studies have documented parasite species on wild and farmed fish from aquaculture sites, few have used qualitative risk analyses to determine the likelihood and consequence of parasite transfer from locally found wild fish to farmed fish. Indeed, most risk assessments for marine fish farming identify hazards from diseases reported in other, often distant, countries. The usefulness of this approach is limited if an endemic parasite with potential to cause serious disease is undetected before the establishment of aquaculture. This study performs a qualitative risk assessment for 57 metazoan parasite species found to infect wild yellowtail kingfish (Seriola lalandi) and Samson fish (S. hippos) in southern Australia to determine real risks to local sea-cage aquaculture of S. lalandi in South Australia and for industry expansion elswhere. Risk was estimated by considering the likelihood and consequence of parasite establishment and proliferation in S. lalandi sea-cage farming. Benedenia Seriolae and Zeuxapta Seriolae (Monogenea) were considered extremely likely to establish and proliferate. B. Seriolae is currently recorded as the highest potential negative consequence for cost-effective sea-cage farming of S. lalandi in Australia, should the industry expand elsewhere. However, B. Seriolae infections can be managed by bathing fish in either hydrogen peroxide or fresh water. Absence of potential treatment methods for Paradeontacylix spp. (Digenea), Kudoa sp. and Unicapsula Seriolae (Myxozoa) suggests that these species may present the highest negative consequences for S. lalandi aquaculture in Australia. However, the presence of myxozoan infection in the flesh of wild South Australian Seriola spp. needs confirmation to determine whether these parasite species present an immediate risk to farmed S. lalandi in South Australia.
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metazoan parasite assemblages of wild Seriola lalandi carangidae from eastern and southern australia
Parasitology International, 2007Co-Authors: Kate S Hutson, Ian D Whittington, Ingo Ernst, Allan J MooneyAbstract:Yellowtail kingfish, Seriola lalandi support significant commercial and recreational fisheries as well as aquaculture operations throughout the world. Metazoan parasite infections of S. lalandi are of considerable economic and ecological importance, yet very little is known about wild parasite assemblages. S. lalandi were collected from the east coast and south coast of Australia and examined for metazoan parasites. Forty-three parasite taxa were identified, including 26 new host records. Four of the parasite species recovered have been previously associated with disease or mortality in Seriola aquaculture. Comparisons are made between ectoparasite and endoparasite prevalence and intensity of S. lalandi from New South Wales and Victoria. S. lalandi sampled from the east coast of Australia shared ectoparasites previously documented from this species in New Zealand, providing support that S. lalandi in the Tasman Sea comprise a single stock. Based on previously used criteria to evaluate the suitability of parasites as biological tags, the monogenean Paramicrocotyloides reticularis Rohde and the copepod Parabrachiella Seriolae Yamaguti and Yamasu may be potentially useful for stock discrimination.
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effect of water temperature on reproductive development of benedenia Seriolae monogenea capsalidae from Seriola lalandi in australia
Diseases of Aquatic Organisms, 2007Co-Authors: Julia A Lackenby, Clinton B Chambers, Ingo Ernst, Ian D WhittingtonAbstract:The monogenean Benedenia Seriolae (Yamaguti, 1934) Meserve, 1938 is a major pathogen of farmed yellowtail kingfish Seriola lalandi in South Australia. To control parasite popu- lations in commercial farms, an understanding of the effect of water temperature on parasite de- velopment is vital. This study investigated the effect of water temperature (14, 18, 22 and 26 ± 0.5°C) on development, growth rates and age at sexual maturity of B. Seriolae. Five distinct developmental stages, defined by the progressive development of reproductive organs, were used to describe devel- opment of B. Seriolae from recently invaded larvae to sexually mature adults. Parasite age at the first sign of sexual maturity (ability to lay eggs) was strongly influenced by water temperature and was attained at 41, 24, 16 and 14 d post infection (p.i.) at 14, 18, 22 and 26 ± 0.5°C respectively. Four parameters (parasite total length, maximum parasite width, accessory sclerite length and anterior hamulus length) were examined for suitability as an index of parasite age. Growth rates for each parameter increased with water temperature; however, mean anterior hamulus length was identified as the most reliable index of parasite age. Equations derived from these data can be used to estimate parasite age and time to sexual maturity at water temperatures ranging from 14 to 26°C. The equa- tions provide a simple tool to assist implementation of strategic treatment plans for B. Seriolae infec- tions in commercial kingfish farms, not only in South Australia but in other localities worldwide where S. lalandi is farmed.
Noritaka Hirazawa - One of the best experts on this subject based on the ideXlab platform.
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differences in sensitivity to the anthelmintic praziquantel by the skin parasitic monogeneans benedenia Seriolae and neobenedenia girellae
Aquaculture, 2013Co-Authors: Noritaka Hirazawa, Kousuke Akiyama, Naoko UmedaAbstract:Abstract The capsalid monogeneans Benedenia Seriolae and Neobenedenia girellae are problematic parasites in the major commercially cultured fish in Japan, carangids Seriola quinqueradiata and Seriola dumerili. This study investigated the efficacy of PZQ against infection with these monogeneans in these two fish species and the differences in sensitivity to PZQ between B. Seriolae and N. girellae in vitro. In-feed PZQ at a dose of 150 mg/kg body weight for three consecutive days resulted in a 76.7% reduction in B. Seriolae intensity in small S. quinqueradiata and a 93.0% reduction in B. Seriolae intensity in small S. dumerili. Benedenia Seriolae intensity was completely eliminated in large fish of both species treated with PZQ. Conversely, PZQ treatment resulted in only a 35.9% reduction in N. girellae intensity in small S. quinqueradiata and a 19.3% reduction in N. girellae intensity in small S. dumerili. Neobenedenia girellae intensity was 76.5% and 25.2% reduced in large S. quinqueradiata and S. dumerili, respectively. In in vitro trials, nearly (80 and 100%) all of the B. Seriolae treated with 0.5 ppm PZQ detached from a culture dish within 60 min. However, greater concentrations of PZQ and longer treatment times were required to detach a similar percentage of N. girellae. Thus, oral PZQ treatment effectively controls B. Seriolae infections in S. quinqueradiata and S. dumerili, but is less effective in controlling N. girellae in both Seriola species.
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the effect of oral antibiotic treatment and freshwater bath treatment on susceptibility to neobenedenia girellae monogenea infection of amberjack Seriola dumerili and yellowtail s quinqueradiata hosts
Aquaculture, 2009Co-Authors: Yasuhiro Ohno, Fumi Kawano, Noritaka HirazawaAbstract:Amberjack Seriola dumerili (Carangidae) and yellowtail S. quinqueradiata, important commercial fish in Japan, are susceptible to parasitic infection with Neobenedenia girellae (Capsalidae) when cultured in floating net cages. To prevent N. girellae infection, a 2- to 5-min freshwater dip is often practiced. In addition, many bacterial diseases, such as vibriosis, pasteurellosis, streptococcosis, mycobacteriosis and nocardiosis, also afflict cultivated Seriola species and oral administration of antibiotics is often necessary. The present study investigated whether oral antibiotics and freshwater bath treatments will influence the susceptibility to N. girellae infection of these two species. The infection intensity and growth of N. girellae on S. dumerili and S. quinqueradiata did not differ significantly between the control group and oxytetracycline, florfenicol, ampicillin, erythromycin or sulfamonomethoxine-treated groups, suggesting that oral antibiotics do not influence the susceptibility to N. girellae infection of S. dumerili or S. quinqueradiata hosts when administered at recommended doses. In contrast, freshwater bath treatment for 2 min significantly increased N. girellae infection on both S. dumerili and S. quinqueradiata compared to control groups exposed to oncomiracidia in the same aquarium. Thus, the susceptibility to N. girellae infection of these species was shown to be increased by freshwater bath treatment. These results may be well considered for controlling N. girellae infections when cultivating Seriola species.
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susceptibility by amberjack Seriola dumerili yellowtail s quinqueradiata and japanese flounder paralichthys olivaceus to neobenedenia girellae monogenea infection and their acquired protection
Aquaculture, 2008Co-Authors: Yasuhiro Ohno, Fumi Kawano, Noritaka HirazawaAbstract:This study investigated: 1) susceptibility differences to infection by Neobenedenia girellae (Capsalidae) between amberjack Seriola dumerili (Carangidae), yellowtail S. quinqueradiata and Japanese flounder Paralichthys olivaceus (Paralichthyidae); 2) growth and egg production of N. girellae on each fish species; 3) acquired protection of each fish species against this parasite. The number of N. girellae on S. dumerili was significantly higher than on S. quinqueradiata and P. olivaceus when these fishes were exposed to oncomiracidia in the same aquarium. Neobenedenia girellae growth on S. dumerili was fastest and, thus the number of eggs laid by parasites on S. dumerili was greater than on the other two species. Seriola dumerili and P. olivaceus, which were previously infected with N. girellae and treated by freshwater bath, acquired partial protection against re-infection by N. girellae. The relative re-infection of three S. dumerili individuals out of eleven individuals was markedly low compared with the initial infection, and the relative initial infection and re-infection on two P. olivaceus out of eleven individuals was markedly low. The results of this study could be useful to control N. girellae infections when cultivating S. dumerili, S. quinqueradiata and P. olivaceus.
Monge Ortiz Raquel - One of the best experts on this subject based on the ideXlab platform.
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Efecto de la sustitución de la harina y el aceite de pescado por fuentes vegetales y animales en la alimentación de la Seriola (Seriola dumerili. Risso, 1810)
'Universitat Politecnica de Valencia', 2020Co-Authors: Monge Ortiz RaquelAbstract:[ES] La Seriola dumerili (Risso, 1810) se presenta como una especie emergente en la acuicultura, con una buena adaptación a la cautividad y un rápido crecimiento. Sin embargo, apenas se dispone de información acerca de la composición adecuada de los piensos para esta especie, lo que es de especial importancia, dado que muchos de los ingredientes óptimos, como las harinas y aceites de pescado, se consideran recursos limitados, tanto desde el punto de vista ambiental como económico. En la presente tesis doctoral, se llevaron a cabo diferentes experimentos en Seriola dumerili, con el objetivo de evaluar el efecto de la sustitución de la harina de pescado y el aceite de pescado en el crecimiento, parámetros nutritivos, eficiencia del crecimiento y calidad del producto final. Los experimentos se iniciaron con una prueba para determinar la digestibilidad de fuentes proteicas alternativas para su inclusión en dietas para la Seriola, con el objetivo de comprobar su idoneidad para esta especie, permitiendo en las siguientes pruebas formular los piensos en base a los coeficientes digestibles. Se ensayon 12 materias primas, vegetales y animales (harinas de: habas, camelina, soja, guisante, girasol, trigo, krill, krill desengrasado, pollo, calamar y pescado). Las proteínas animales fueron las que resultaron más adecuadas para la especie, y las vegetales por sí mismas no ofrecían un buen balance nutricional, aunque combinadas con otras fuentes proteicas, podían ser consideradas un ingrediente proteico. Posteriormente, se llevó a cabo un experimento de sustitución de la harina de pescado por una mezcla de fuentes proteicas animales y vegetales. El experimento se inició con peces de 39 g y se finalizó con un peso medio de 365 g tras 154 días. Se ensayaron cuatro niveles de sustitución de la harina de pescado (0%, 33%, 66% y 100%). De los resultados de esta prueba se concluyó que la sustitución total de la harina de pescado no es posible para esta especie, ya que el crecimiento fue mucho menor, debido principalmente a la menor digestibilidad de los aminoácidos esenciales, así como de la energía, además con este pienso se observó una mayor mortalidad. Con la sustitución del 66% se obtuvieron buenos resultados de crecimiento, eficiencia nutritiva y una elevada supervivencia. A partir de los resultados obtenidos en la primera prueba de fuentes proteicas, se inició un segundo experimento con peces de 530 g (los peces fueron alimentados con los mismos piensos durante todo el periodo de crecimiento) y finalizó tras 84 días con un peso medio de 850 g de peso medio. Se ensayaron los tres piensos de la prueba anterior que mejores resultados habían proporcionado (0%, 33%, 66% de sustitución de harina de pescado), con el objetivo de estudiar el efecto de éstos en la calidad de la carne (perfil de ácidos grasos, metales pesados, análisis sensorial y organoléptico) de peces a talla comercial. Al final del experimento, se observó una reducción en la mayor parte de los ácidos grasos a medida que aumentaba la sustitución. En cuanto al nivel de metales pesados en el músculo, éstos no excedieron en ningún caso los valores recomendados por la UE. Algunos de los parámetros fisicoquímicos del filete sí se vieron afectados, pero no se reflejó en el análisis organoléptico, donde los jueces no fueron capaces de apreciar diferencias entre dietas, excepto en el color. En el siguiente experimento se estudió el efecto de la sustitución del aceite de pescado por una mezcla de aceites vegetales (utilizando una mezcla de aceite de palma y aceite de linaza en proporción 4:1). La fase de crecimiento se inició con peces de 39 g y se finalizó con 390 g de peso medio tras 154 días de experimento. Se ensayaron tres niveles de sustitución (0%, 50% y 100% del aceite de pescado). Se observó que la mezcla de aceites vegetales puede ser utilizada para sustituir completamente el aceite de pescado en juveniles de Seriola dumerili sin afectar al crecimiento ni la utilización del alimento. Asimismo, el perfil de ácidos grasos esenciales en la dieta cubrió las necesidades de los juveniles de la Seriola sin afectar a la salud de los peces, ni a las características nutricionales del pescado. De los resultados de la presente tesis, se confirma que, la sustitución de harina de pescado en piensos por la mezcla de fuentes proteicas alternativas ensayada, no afecta negativamente al crecimiento de la afectar al crecimiento ni la utilización del alimento. Asimismo, el perfil de ácidos grasos esenciales en la dieta cubrió las necesidades de los juveniles de la Seriola sin afectar a la salud de los peces, ni a las características nutricionales del pescado. De los resultados de la presente tesis, se confirma que, la sustitución de harina de pescado en piensos por la mezcla de fuentes proteicas alternativas ensayada, no afecta negativamente al crecimiento de la Seriola en periodos largos de alimentación, así como a parámetros de calidad como el perfil de ácidos grasos del filete, cuando dichas sustituciones son menores del 66%. En cuanto a la sustitución lipídica, la sustitución completa de aceite de pescado por aceites vegetales es posible en juveniles de S. dumerili sin afectar al crecimiento, rendimiento, utilización del alimento y salud de los peces, lo que deberá de tenerse en cuenta en futuras formulaciones de piensos específicos para esta especie.[EN] Seriola dumerili (Risso, 1810) is presented as a emerging specie in aquaculture, with a good adaptation to captivity and a rapid growth, but actually but not much information is currently available on the optimal feed composition for this specie. This is especially important since many of the optimal ingredients, such as fishmeal and fish oils, are considered limited resources from an environmental and economic point of view. In the present Ph. D thesis, different experiments were carried out in Seriola dumerili, with the objective of evaluate the effect of fish meal ad fish oil substitution on growth, nutritional parameters, growth efficiency and the quality of the final product. Experiments with alternative protein sources were initiated with a digestibility test of raw materials recommended for the Seriola dumerili, in order to check their suitability for this specie and permiting in the next experiments formulate the diets according the obtained results. 12 raw materials based on vegetables and animal sources, were tested (meals from: beans, camelina, soya, peas, sunflower, wheat, krill, degreased krill, chicken, squid and fish). Animal proteins were selected as the most adequate proteins for this specie. In addition, it was demonstrated that vegetable proteins alone did not present a good nutritional balance; however, they could be used as an ingredient for S. dumerili diets in combination with other protein sources. Based on the results obtained, fish meal was replaced for a mixture of animal and vegetable protein sources. This study was started with 39 g of fish and it was finished with 365 g after 154 days. Four levels of fish meal substitution were studied (0%, 33%, 66%, 100%). With the results obtained in this experiment, it concludes that the total substitution of fish meal was not viable due to the lower digestibility capacity of essential amino acids and energy. In addition, higher mortality level was found after the ingestion of this diet. It was concluded that a replacement of 66 % led to a successful growth, nutritional efficiency and better survival results. Considering results obtained in the first protein source test, a second study was carried out. It started with 530 g of fish (the fish were feed with the same diets during all the growth period) and ended up with 850 g after 84 days. The three diets with the best results of the previous experiments were asayed (0%, 33%, 66% of fish meal substitution) with the aim to study their effect in the meat quality (fatty acids profile, heavy metals, sensory and organoleptic analyses) in fish with commercial size. At the end of the experiment a reduction of most fatty acids with the increase of substitution level was detected. In addition, heavy metal levels in muscle did not exceed in any case the values permitted by the European Commission. Thus, they do not present a risk for human health. Otherwise, some of the physicochemical properties of the Seriola dumerili fillet were affected, however, this effect was not reflected on the organoleptic analyses, where tasters were not able to appreciate differences between diets, excepting for the final color. In the next experiment, the effect of replacing the fish oil for a mixture of vegetable oils (palm oil and linseed oil in a proportion of 4:1) was elucidated. This study was started with fishes that weighted 39 g and finished with 390 g after 154 days. Three substitution levels were used (0%, 50% and 100% of fish oil). It was shown that the vegetable mixture can be used to completely replace the fish oil for young Seriola dumerili fishes, without affecting growth and nutrient efficiency. In addition, fatty acids profile in diet, fulfilled the need of Seriola dumerili juveniles without influencing their health and their final nutritional characteristics. Based on the results obtained in this Ph. D thesis, it can be confirmed that feeding Seriola dumerili with fish meal substitution during long periods of time, do not affects negatively its growth and quality parameters such as fatty acids profile, especially with substitutions under than 66%. Good results were also obtained with lower percentages of substitution levels. Regarding to the lipid substitution, a complete substitution of fish oil for vegetable oils was feasible for young Seriola dumerili, without affecting their growth, yield, feed utilization and health, which should be considered in future feed formulations specific to this species.[CA] La Seriola dumerili (Risso, 1810) es presenta com una espècie emergent en l'aqüicultura, amb bona adaptació a la captivitat i un ràpid creixement, però actualment no es disposa de molta informació sobre la composició adequada dels pinsos per a aquesta espècie, la qual cosa és d'especial importància donat el fet que molts dels ingredients òptims, com les farines i olis de peix, es consideren recursos limitats, tant des del punt de vista ambiental com econòmic. En la present tesi doctoral, es van a dur terme diferents experiments en Seriola dumerili, amb l'objectiu d'avaluar l'efecte de la substitució de la farina de peix i l'oli de peix en el creixement, paràmetres nutritius eficiència del creixement i qualitat del producte final. Els experiments es van iniciar amb una proba per a determinar la digestibilitat amb fonts proteiques alternatives per a la inclusió de dietes en la Seriola, amb l'objectiu de comprovar la seua idoneïtat per a aquesta espècie permitint en les següents probes formular els pinsos sobre la base dels coeficients digestibles. Es van assajar 12 matèries primeres, vegetals i animals (farines de: faves, camelina, soja, pésol, gira-sol, blat, krill, krill desgreixat, au, calamar i peix). Les proteïnes animals van ser les que van resultar més adequades per a l'espècie i les vegetals per si mateixes no oferien un bon balanç nutricional, encara que combinades amb altres fonts proteiques, podien ser considerades un ingredient proteic. Posteriorment, es va dur a terme un experiment de substitució de la farina de peix per una mescla de fonts proteiques animals i vegetals. L'experiment es va iniciar amb peixos de 39g i es va finalitzar amb una pes mig de 365 g després de 154 dies. Es van assajar quatre nivells de substitució de la farina de peix (0%, 33%, 66% i 100%). Dels resultats d'aquesta prova es va concloure que la substitució total de la farina de peix no és possible per a aquesta espècie, ja que el creixement va ser molt menor, degut principalment a la menor digestibilitat dels aminoàcids essencials, així com de l'energia, a més amb aquest pinso va haver-hi una major mortalitat. Amb la substitució del 66% es va obtindre un bon resultat de creixement, eficiència nutritiva i una alta supervivència. A partir dels resultats obtinguts en la primera prova de fonts proteiques es va iniciar un segon experiment amb peixos de 530 g (els peixos van ser alimentats amb els mateixos pinsos durant tot el període de creixement) i va finalitzar després de 84 dies amb una grandària de 850 g de pes mitjà. Es van assajar els tres pinsos de la prova anterior que millors resultats havien proporcionat (0%, 33%, 66% se substitució de farina de peix), amb l'objectiu d'estudiar l'efecte d'aquests mateixos pinsos en la qualitat de la carn (perfil d'àcids greixos, metalls pesats, anàlisi sensorial i organolèptic) en peixos aconseguint una talla comercial. Al final de l'experiment, es va observar una reducció en la major part dels àcids greixos a mesura que augmentava la substitució. En quant al nivell de metalls pesats en el múscul, aquests no van excedir en cap cas els valors recomanats per la UE. Alguns dels paràmetres fisicoquímics del filet sí que es van veure afectats, però no es va reflectir en l'anàlisi organolèptic, on els tastadors no van ser capaços d'apreciar diferències entre dietes, excepte en el color. En el següent experiment es va estudiar l'efecte de la substitució de l'oli de peix per una mescla d'olis vegetals utilitzant una mescla d'oli de palma i oli de llinosa en proporció 4:1). L’experiment es va iniciar amb peixos de 39 g i es va finalitzar amb 390 g de pes mitjà després de 154 dies d'experiment. Es van assajar tres nivells de substitució (0%, 50% i 100% de l'oli de peix). Es va observar que la mescla d’olis vegetals pot ser utilitzada per a substituir completament l’oli de peix en juvenils de Seriola dumerili no va afectar el creixement ni la utilització de l’aliment. Així mateix, el perfil d’àcids greixos essencials en la dieta, va cobrir les necessitats dels juvenils de la Seriola sense afectar la salut dels peixos ni a les característiques nutricionals del peix. Dels resultats de la present tesi, es confirma que, en períodes llargs d’alimentació la substitució de farina de peix per la mescla de fonts proteiques alternatives assajada en pinsos, no afecta negativament al creixement de la Seriola i a paràmetres de qualitat com el perfil d'àcids greixos del filet, quan aquestes substitucions són menors del 66%. Quant a la substitució lipídica, la substitució completa d'oli de peix per olis vegetals és possible en juvenils de S. dumerili sense afectar el creixement, rendiment, utilització de l’aliment i salut dels peixos, la qual cosa haurà de tindre’s en compte en futures formulacions de pinsos específics per a aquesta espècie.Monge Ortiz, R. (2020). Efecto de la sustitución de la harina y el aceite de pescado por fuentes vegetales y animales en la alimentación de la Seriola (Seriola dumerili. Risso, 1810) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/153798TESI
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Efecto de la sustitución de la harina y el aceite de pescado por fuentes vegetales y animales en la alimentación de la Seriola (Seriola dumerili. Risso, 1810)
'Universitat Politecnica de Valencia', 2020Co-Authors: Monge Ortiz RaquelAbstract:Tesis por compendio[ES] La Seriola dumerili (Risso, 1810) se presenta como una especie emergente en la acuicultura, con una buena adaptación a la cautividad y un rápido crecimiento. Sin embargo, apenas se dispone de información acerca de la composición adecuada de los piensos para esta especie, lo que es de especial importancia, dado que muchos de los ingredientes óptimos, como las harinas y aceites de pescado, se consideran recursos limitados, tanto desde el punto de vista ambiental como económico. En la presente tesis doctoral, se llevaron a cabo diferentes experimentos en Seriola dumerili, con el objetivo de evaluar el efecto de la sustitución de la harina de pescado y el aceite de pescado en el crecimiento, parámetros nutritivos, eficiencia del crecimiento y calidad del producto final. Los experimentos se iniciaron con una prueba para determinar la digestibilidad de fuentes proteicas alternativas para su inclusión en dietas para la Seriola, con el objetivo de comprobar su idoneidad para esta especie, permitiendo en las siguientes pruebas formular los piensos en base a los coeficientes digestibles. Se ensayon 12 materias primas, vegetales y animales (harinas de: habas, camelina, soja, guisante, girasol, trigo, krill, krill desengrasado, pollo, calamar y pescado). Las proteínas animales fueron las que resultaron más adecuadas para la especie, y las vegetales por sí mismas no ofrecían un buen balance nutricional, aunque combinadas con otras fuentes proteicas, podían ser consideradas un ingrediente proteico. Posteriormente, se llevó a cabo un experimento de sustitución de la harina de pescado por una mezcla de fuentes proteicas animales y vegetales. El experimento se inició con peces de 39 g y se finalizó con un peso medio de 365 g tras 154 días. Se ensayaron cuatro niveles de sustitución de la harina de pescado (0%, 33%, 66% y 100%). De los resultados de esta prueba se concluyó que la sustitución total de la harina de pescado no es posible para esta especie, ya que el crecimiento fue mucho menor, debido principalmente a la menor digestibilidad de los aminoácidos esenciales, así como de la energía, además con este pienso se observó una mayor mortalidad. Con la sustitución del 66% se obtuvieron buenos resultados de crecimiento, eficiencia nutritiva y una elevada supervivencia. A partir de los resultados obtenidos en la primera prueba de fuentes proteicas, se inició un segundo experimento con peces de 530 g (los peces fueron alimentados con los mismos piensos durante todo el periodo de crecimiento) y finalizó tras 84 días con un peso medio de 850 g de peso medio. Se ensayaron los tres piensos de la prueba anterior que mejores resultados habían proporcionado (0%, 33%, 66% de sustitución de harina de pescado), con el objetivo de estudiar el efecto de éstos en la calidad de la carne (perfil de ácidos grasos, metales pesados, análisis sensorial y organoléptico) de peces a talla comercial. Al final del experimento, se observó una reducción en la mayor parte de los ácidos grasos a medida que aumentaba la sustitución. En cuanto al nivel de metales pesados en el músculo, éstos no excedieron en ningún caso los valores recomendados por la UE. Algunos de los parámetros fisicoquímicos del filete sí se vieron afectados, pero no se reflejó en el análisis organoléptico, donde los jueces no fueron capaces de apreciar diferencias entre dietas, excepto en el color. En el siguiente experimento se estudió el efecto de la sustitución del aceite de pescado por una mezcla de aceites vegetales (utilizando una mezcla de aceite de palma y aceite de linaza en proporción 4:1). La fase de crecimiento se inició con peces de 39 g y se finalizó con 390 g de peso medio tras 154 días de experimento. Se ensayaron tres niveles de sustitución (0%, 50% y 100% del aceite de pescado). Se observó que la mezcla de aceites vegetales puede ser utilizada para sustituir completamente el aceite de pescado en juveniles de Seriola dumerili sin afectar al crecimiento ni la utilización del alimento. Asimismo, el perfil de ácidos grasos esenciales en la dieta cubrió las necesidades de los juveniles de la Seriola sin afectar a la salud de los peces, ni a las características nutricionales del pescado. De los resultados de la presente tesis, se confirma que, la sustitución de harina de pescado en piensos por la mezcla de fuentes proteicas alternativas ensayada, no afecta negativamente al crecimiento de la afectar al crecimiento ni la utilización del alimento. Asimismo, el perfil de ácidos grasos esenciales en la dieta cubrió las necesidades de los juveniles de la Seriola sin afectar a la salud de los peces, ni a las características nutricionales del pescado. De los resultados de la presente tesis, se confirma que, la sustitución de harina de pescado en piensos por la mezcla de fuentes proteicas alternativas ensayada, no afecta negativamente al crecimiento de la Seriola en periodos largos de alimentación, así como a parámetros de calidad como el perfil de ácidos grasos del filete, cuando dichas sustituciones son menores del 66%. En cuanto a la sustitución lipídica, la sustitución completa de aceite de pescado por aceites vegetales es posible en juveniles de S. dumerili sin afectar al crecimiento, rendimiento, utilización del alimento y salud de los peces, lo que deberá de tenerse en cuenta en futuras formulaciones de piensos específicos para esta especie.[EN] Seriola dumerili (Risso, 1810) is presented as a emerging specie in aquaculture, with a good adaptation to captivity and a rapid growth, but actually but not much information is currently available on the optimal feed composition for this specie. This is especially important since many of the optimal ingredients, such as fishmeal and fish oils, are considered limited resources from an environmental and economic point of view. In the present Ph. D thesis, different experiments were carried out in Seriola dumerili, with the objective of evaluate the effect of fish meal ad fish oil substitution on growth, nutritional parameters, growth efficiency and the quality of the final product. Experiments with alternative protein sources were initiated with a digestibility test of raw materials recommended for the Seriola dumerili, in order to check their suitability for this specie and permiting in the next experiments formulate the diets according the obtained results. 12 raw materials based on vegetables and animal sources, were tested (meals from: beans, camelina, soya, peas, sunflower, wheat, krill, degreased krill, chicken, squid and fish). Animal proteins were selected as the most adequate proteins for this specie. In addition, it was demonstrated that vegetable proteins alone did not present a good nutritional balance; however, they could be used as an ingredient for S. dumerili diets in combination with other protein sources. Based on the results obtained, fish meal was replaced for a mixture of animal and vegetable protein sources. This study was started with 39 g of fish and it was finished with 365 g after 154 days. Four levels of fish meal substitution were studied (0%, 33%, 66%, 100%). With the results obtained in this experiment, it concludes that the total substitution of fish meal was not viable due to the lower digestibility capacity of essential amino acids and energy. In addition, higher mortality level was found after the ingestion of this diet. It was concluded that a replacement of 66 % led to a successful growth, nutritional efficiency and better survival results. Considering results obtained in the first protein source test, a second study was carried out. It started with 530 g of fish (the fish were feed with the same diets during all the growth period) and ended up with 850 g after 84 days. The three diets with the best results of the previous experiments were asayed (0%, 33%, 66% of fish meal substitution) with the aim to study their effect in the meat quality (fatty acids profile, heavy metals, sensory and organoleptic analyses) in fish with commercial size. At the end of the experiment a reduction of most fatty acids with the increase of substitution level was detected. In addition, heavy metal levels in muscle did not exceed in any case the values permitted by the European Commission. Thus, they do not present a risk for human health. Otherwise, some of the physicochemical properties of the Seriola dumerili fillet were affected, however, this effect was not reflected on the organoleptic analyses, where tasters were not able to appreciate differences between diets, excepting for the final color. In the next experiment, the effect of replacing the fish oil for a mixture of vegetable oils (palm oil and linseed oil in a proportion of 4:1) was elucidated. This study was started with fishes that weighted 39 g and finished with 390 g after 154 days. Three substitution levels were used (0%, 50% and 100% of fish oil). It was shown that the vegetable mixture can be used to completely replace the fish oil for young Seriola dumerili fishes, without affecting growth and nutrient efficiency. In addition, fatty acids profile in diet, fulfilled the need of Seriola dumerili juveniles without influencing their health and their final nutritional characteristics. Based on the results obtained in this Ph. D thesis, it can be confirmed that feeding Seriola dumerili with fish meal substitution during long periods of time, do not affects negatively its growth and quality parameters such as fatty acids profile, especially with substitutions under than 66%. Good results were also obtained with lower percentages of substitution levels. Regarding to the lipid substitution, a complete substitution of fish oil for vegetable oils was feasible for young Seriola dumerili, without affecting their growth, yield, feed utilization and health, which should be considered in future feed formulations specific to this species.[CA] La Seriola dumerili (Risso, 1810) es presenta com una espècie emergent en l'aqüicultura, amb bona adaptació a la captivitat i un ràpid creixement, però actualment no es disposa de molta informació sobre la composició adequada dels pinsos per a aquesta espècie, la qual cosa és d'especial importància donat el fet que molts dels ingredients òptims, com les farines i olis de peix, es consideren recursos limitats, tant des del punt de vista ambiental com econòmic. En la present tesi doctoral, es van a dur terme diferents experiments en Seriola dumerili, amb l'objectiu d'avaluar l'efecte de la substitució de la farina de peix i l'oli de peix en el creixement, paràmetres nutritius eficiència del creixement i qualitat del producte final. Els experiments es van iniciar amb una proba per a determinar la digestibilitat amb fonts proteiques alternatives per a la inclusió de dietes en la Seriola, amb l'objectiu de comprovar la seua idoneïtat per a aquesta espècie permitint en les següents probes formular els pinsos sobre la base dels coeficients digestibles. Es van assajar 12 matèries primeres, vegetals i animals (farines de: faves, camelina, soja, pésol, gira-sol, blat, krill, krill desgreixat, au, calamar i peix). Les proteïnes animals van ser les que van resultar més adequades per a l'espècie i les vegetals per si mateixes no oferien un bon balanç nutricional, encara que combinades amb altres fonts proteiques, podien ser considerades un ingredient proteic. Posteriorment, es va dur a terme un experiment de substitució de la farina de peix per una mescla de fonts proteiques animals i vegetals. L'experiment es va iniciar amb peixos de 39g i es va finalitzar amb una pes mig de 365 g després de 154 dies. Es van assajar quatre nivells de substitució de la farina de peix (0%, 33%, 66% i 100%). Dels resultats d'aquesta prova es va concloure que la substitució total de la farina de peix no és possible per a aquesta espècie, ja que el creixement va ser molt menor, degut principalment a la menor digestibilitat dels aminoàcids essencials, així com de l'energia, a més amb aquest pinso va haver-hi una major mortalitat. Amb la substitució del 66% es va obtindre un bon resultat de creixement, eficiència nutritiva i una alta supervivència. A partir dels resultats obtinguts en la primera prova de fonts proteiques es va iniciar un segon experiment amb peixos de 530 g (els peixos van ser alimentats amb els mateixos pinsos durant tot el període de creixement) i va finalitzar després de 84 dies amb una grandària de 850 g de pes mitjà. Es van assajar els tres pinsos de la prova anterior que millors resultats havien proporcionat (0%, 33%, 66% se substitució de farina de peix), amb l'objectiu d'estudiar l'efecte d'aquests mateixos pinsos en la qualitat de la carn (perfil d'àcids greixos, metalls pesats, anàlisi sensorial i organolèptic) en peixos aconseguint una talla comercial. Al final de l'experiment, es va observar una reducció en la major part dels àcids greixos a mesura que augmentava la substitució. En quant al nivell de metalls pesats en el múscul, aquests no van excedir en cap cas els valors recomanats per la UE. Alguns dels paràmetres fisicoquímics del filet sí que es van veure afectats, però no es va reflectir en l'anàlisi organolèptic, on els tastadors no van ser capaços d'apreciar diferències entre dietes, excepte en el color. En el següent experiment es va estudiar l'efecte de la substitució de l'oli de peix per una mescla d'olis vegetals utilitzant una mescla d'oli de palma i oli de llinosa en proporció 4:1). L’experiment es va iniciar amb peixos de 39 g i es va finalitzar amb 390 g de pes mitjà després de 154 dies d'experiment. Es van assajar tres nivells de substitució (0%, 50% i 100% de l'oli de peix). Es va observar que la mescla d’olis vegetals pot ser utilitzada per a substituir completament l’oli de peix en juvenils de Seriola dumerili no va afectar el creixement ni la utilització de l’aliment. Així mateix, el perfil d’àcids greixos essencials en la dieta, va cobrir les necessitats dels juvenils de la Seriola sense afectar la salut dels peixos ni a les característiques nutricionals del peix. Dels resultats de la present tesi, es confirma que, en períodes llargs d’alimentació la substitució de farina de peix per la mescla de fonts proteiques alternatives assajada en pinsos, no afecta negativament al creixement de la Seriola i a paràmetres de qualitat com el perfil d'àcids greixos del filet, quan aquestes substitucions són menors del 66%. Quant a la substitució lipídica, la substitució completa d'oli de peix per olis vegetals és possible en juvenils de S. dumerili sense afectar el creixement, rendiment, utilització de l’aliment i salut dels peixos, la qual cosa haurà de tindre’s en compte en futures formulacions de pinsos específics per a aquesta espècie.Monge Ortiz, R. (2020). Efecto de la sustitución de la harina y el aceite de pescado por fuentes vegetales y animales en la alimentación de la Seriola (Seriola dumerili. Risso, 1810) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/153798TESISCompendi
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A novel C-type lectin gene is a strong candidate gene for Benedenia disease resistance in Japanese yellowtail, Seriola quinqueradiata.
Developmental and comparative immunology, 2017Co-Authors: Masatoshi Nakamoto, Kazunori Yoshida, Akiyuki Ozaki, Tsutomu Noda, Yusuke Takeuchi, Kazuki Akita, Ryo Kumagai, Junpei Suzuki, Takashi Koyama, Kazuo ArakiAbstract:Abstract Little is known about mechanisms of resistance to parasitic diseases in marine finfish. Benedenia disease is caused by infection by the monogenean parasite Benedenia Seriolae . Previous quantitative trait locus (QTL) analyses have identified a major QTL associated with resistance to Benedenia disease in linkage group Squ2 of the Japanese yellowtail/amberjack Seriola quinqueradiata. To uncover the bioregulatory mechanism of Benedenia disease resistance, complete Illumina sequencing of BAC clones carrying genomic DNA for the QTL region in linkage group Squ2 was performed to reveal a novel C-type lectin in this region. Expression of the mRNA of this C-type lectin was detected in skin tissue parasitized by B. Seriolae . Scanning for single nucleotide polymorphisms (SNPs) uncovered a SNP in the C-type lectin/C-type lectin-like domain that was significantly associated with B. Seriolae infection levels. These results strongly suggest that the novel C-type lectin gene controls resistance to Benedenia disease in Japanese yellowtails.
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T: Quantitative trait loci (QTL) associated with resistance to a parasitic disease (Benedenia Seriolae) in yellowtail (Seriola quinqueradiata) through genome wide analysis
2016Co-Authors: Akiyuki Ozaki, Kanako Fuji, Kazunori Yoshida, Satoshi Kubota, Jun-ya Aoki, Kazuki Akita, Junpei Suzuki, Wataru Kai, Yumi Kawabata, Takashi KoyamaAbstract:Benedenia infections caused by the monogenean fluke ectoparasite Benedenia Seriolae seriously impact marine finfish aquaculture. Genetic variation has been inferred to play a significant role in determining the susceptibility to this parasitic disease. To evaluate the genetic basis of Benedenia disease resistance in yellowtail (Seriola quinqueradiata), a genome-wide and chromosome-wide linkage analyses were initiated using F1 yellowtail families (n = 90 per family) based on a high-density linkage map with 860 microsatellite and 142 single nucleotide polymorphism (SNP) markers. Two major quantitative trait loci (QTL) regions on linkage groups Squ2 (BDR-1) and Squ20 (BDR-2) were identified. These QTL regions explained 32.9–35.5 % of the phenotypic variance. On the other hand, we investigated the relationship between QTL for susceptibility to B. Seriolae and QTL for fish body size. The QTL related to growth was found on another linkage group (Squ7). As a result, this is the first genetic evidence that contributes to detailing phenotypic resistance to Benedenia disease, and the result
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Quantitative Trait Loci (QTL) Associated with Resistance to a Monogenean Parasite (Benedenia Seriolae) in Yellowtail (Seriola quinqueradiata) through Genome Wide Analysis
PloS one, 2013Co-Authors: Akiyuki Ozaki, Kanako Fuji, Kazunori Yoshida, Satoshi Kubota, Jun-ya Aoki, Kazuki Akita, Junpei Suzuki, Wataru Kai, Yumi Kawabata, Takashi KoyamaAbstract:Benedenia infections caused by the monogenean fluke ectoparasite Benedenia Seriolae seriously impact marine finfish aquaculture. Genetic variation has been inferred to play a significant role in determining the susceptibility to this parasitic disease. To evaluate the genetic basis of Benedenia disease resistance in yellowtail (Seriola quinqueradiata), a genome-wide and chromosome-wide linkage analyses were initiated using F1 yellowtail families (n = 90 per family) based on a high-density linkage map with 860 microsatellite and 142 single nucleotide polymorphism (SNP) markers. Two major quantitative trait loci (QTL) regions on linkage groups Squ2 (BDR-1) and Squ20 (BDR-2) were identified. These QTL regions explained 32.9–35.5% of the phenotypic variance. On the other hand, we investigated the relationship between QTL for susceptibility to B. Seriolae and QTL for fish body size. The QTL related to growth was found on another linkage group (Squ7). As a result, this is the first genetic evidence that contributes to detailing phenotypic resistance to Benedenia disease, and the results will help resolve the mechanism of resistance to this important parasitic infection of yellowtail.
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Whole Genome Sequencing of Greater Amberjack (Seriola dumerili) for SNP Identification on Aligned Scaffolds and Genome Structural Variation Analysis Using Parallel Resequencing
Hindawi Limited, 2018Co-Authors: Kazuo Araki, Akiyuki Ozaki, Jun-ya Aokic, Junya Kawase, Kazuhisa Hamada, Hiroshi Fujimoto, Ikki Yamamoto, Hironori UsukiAbstract:Greater amberjack (Seriola dumerili) is distributed in tropical and temperate waters worldwide and is an important aquaculture fish. We carried out de novo sequencing of the greater amberjack genome to construct a reference genome sequence to identify single nucleotide polymorphisms (SNPs) for breeding amberjack by marker-assisted or gene-assisted selection as well as to identify functional genes for biological traits. We obtained 200 times coverage and constructed a high-quality genome assembly using next generation sequencing technology. The assembled sequences were aligned onto a yellowtail (Seriola quinqueradiata) radiation hybrid (RH) physical map by sequence homology. A total of 215 of the longest amberjack sequences, with a total length of 622.8 Mbp (92% of the total length of the genome scaffolds), were lined up on the yellowtail RH map. We resequenced the whole genomes of 20 greater amberjacks and mapped the resulting sequences onto the reference genome sequence. About 186,000 nonredundant SNPs were successfully ordered on the reference genome. Further, we found differences in the genome structural variations between two greater amberjack populations using BreakDancer. We also analyzed the greater amberjack transcriptome and mapped the annotated sequences onto the reference genome sequence
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A novel C-type lectin gene is a strong candidate gene for Benedenia disease resistance in Japanese yellowtail, Seriola quinqueradiata.
Developmental and comparative immunology, 2017Co-Authors: Masatoshi Nakamoto, Kazunori Yoshida, Akiyuki Ozaki, Tsutomu Noda, Yusuke Takeuchi, Kazuki Akita, Ryo Kumagai, Junpei Suzuki, Takashi Koyama, Kazuo ArakiAbstract:Abstract Little is known about mechanisms of resistance to parasitic diseases in marine finfish. Benedenia disease is caused by infection by the monogenean parasite Benedenia Seriolae . Previous quantitative trait locus (QTL) analyses have identified a major QTL associated with resistance to Benedenia disease in linkage group Squ2 of the Japanese yellowtail/amberjack Seriola quinqueradiata. To uncover the bioregulatory mechanism of Benedenia disease resistance, complete Illumina sequencing of BAC clones carrying genomic DNA for the QTL region in linkage group Squ2 was performed to reveal a novel C-type lectin in this region. Expression of the mRNA of this C-type lectin was detected in skin tissue parasitized by B. Seriolae . Scanning for single nucleotide polymorphisms (SNPs) uncovered a SNP in the C-type lectin/C-type lectin-like domain that was significantly associated with B. Seriolae infection levels. These results strongly suggest that the novel C-type lectin gene controls resistance to Benedenia disease in Japanese yellowtails.
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T: Quantitative trait loci (QTL) associated with resistance to a parasitic disease (Benedenia Seriolae) in yellowtail (Seriola quinqueradiata) through genome wide analysis
2016Co-Authors: Akiyuki Ozaki, Kanako Fuji, Kazunori Yoshida, Satoshi Kubota, Jun-ya Aoki, Kazuki Akita, Junpei Suzuki, Wataru Kai, Yumi Kawabata, Takashi KoyamaAbstract:Benedenia infections caused by the monogenean fluke ectoparasite Benedenia Seriolae seriously impact marine finfish aquaculture. Genetic variation has been inferred to play a significant role in determining the susceptibility to this parasitic disease. To evaluate the genetic basis of Benedenia disease resistance in yellowtail (Seriola quinqueradiata), a genome-wide and chromosome-wide linkage analyses were initiated using F1 yellowtail families (n = 90 per family) based on a high-density linkage map with 860 microsatellite and 142 single nucleotide polymorphism (SNP) markers. Two major quantitative trait loci (QTL) regions on linkage groups Squ2 (BDR-1) and Squ20 (BDR-2) were identified. These QTL regions explained 32.9–35.5 % of the phenotypic variance. On the other hand, we investigated the relationship between QTL for susceptibility to B. Seriolae and QTL for fish body size. The QTL related to growth was found on another linkage group (Squ7). As a result, this is the first genetic evidence that contributes to detailing phenotypic resistance to Benedenia disease, and the result
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Quantitative Trait Loci (QTL) Associated with Resistance to a Monogenean Parasite (Benedenia Seriolae) in Yellowtail (Seriola quinqueradiata) through Genome Wide Analysis
PloS one, 2013Co-Authors: Akiyuki Ozaki, Kanako Fuji, Kazunori Yoshida, Satoshi Kubota, Jun-ya Aoki, Kazuki Akita, Junpei Suzuki, Wataru Kai, Yumi Kawabata, Takashi KoyamaAbstract:Benedenia infections caused by the monogenean fluke ectoparasite Benedenia Seriolae seriously impact marine finfish aquaculture. Genetic variation has been inferred to play a significant role in determining the susceptibility to this parasitic disease. To evaluate the genetic basis of Benedenia disease resistance in yellowtail (Seriola quinqueradiata), a genome-wide and chromosome-wide linkage analyses were initiated using F1 yellowtail families (n = 90 per family) based on a high-density linkage map with 860 microsatellite and 142 single nucleotide polymorphism (SNP) markers. Two major quantitative trait loci (QTL) regions on linkage groups Squ2 (BDR-1) and Squ20 (BDR-2) were identified. These QTL regions explained 32.9–35.5% of the phenotypic variance. On the other hand, we investigated the relationship between QTL for susceptibility to B. Seriolae and QTL for fish body size. The QTL related to growth was found on another linkage group (Squ7). As a result, this is the first genetic evidence that contributes to detailing phenotypic resistance to Benedenia disease, and the results will help resolve the mechanism of resistance to this important parasitic infection of yellowtail.
