RESUMO

Live food in the initial life stages of neotropical fish is essential for their development and health; however, it can significantly increase production costs. This study uses complete diets with varying moisture contents (47%, 35%, 24%, and 8%) as a cost-effective alternative in the co-feeding phase of surubim larvae, assessing their influence on development, digestive enzymes, and liver metabolism. In a completely randomized design, 3200 three-day-old Pseudoplatystoma sp. larvae (0.001 g) were distributed evenly among 16 aquariums (20 L), with 200 individuals per aquarium. For the first five days, all larvae were fed Artemia exclusively, after which they were fed experimental diets with varying levels of humidity (47%, 35%, 24%, and 8%) six times a day across four treatments and four replicates. The 21-day feeding trial demonstrated that larvae fed with 24% and 8% moisture diets exhibited increased (p < 0.05) weight gain, final length, and protein efficiency rate. The remaining growth parameters (i.e., specific growth rate and condition factor) did not show significant differences (p > 0.05) among the dietary treatments. Enzymatic analysis revealed that the 47% moisture diet enhanced the amylase and alkaline phosphatase activities, whereas the 24% and 35% moisture diets elevated the lipase and protease activities. The 47% moisture diet also resulted in increased alanine aminotransferase, aspartate aminotransferase, and albumin levels, along with visible hepatic histopathologies in samples, such as visible lipid vacuoles, displacement of the nucleus of the hepatocyte, and increased sinusoid spaces. No significant liver changes were observed in fish fed with other diets. Principal component analysis showed that diets with 8-24% moisture content were the most beneficial during the co-feeding phase of surubim larviculture.

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The aim of this study was to develop a feeding protocol for the larviculture of Apistogramma cacatuoides, using the histological approach to larval nutrition conditions. For this, three experiments were carried out. Experiment 1 was carried out in a randomized design to determine the optimal amount of Artemia nauplii (AN) per larva, and three treatments were evaluated: P1-feeding with 25 A. nauplii per larva (AN/L) during the first 5 days, followed by 50 AN/L from the 6th to the 10th day and 100 AN/L from the 11th to the 20th day; P2 and P3-37 and 50 AN/L during the first 5 days, 75 and 100 AN/L from the 6th to the 10th day and 150 and 200 AN/L from the 11th to the 20th day. Experiment 2 was carried out in a randomized design to determine the daily frequency of feeding and evaluated four feeding frequencies: F1-feeding only once a day (09:00); (F2)-feeding twice a day (09:00 and 17:00); F3-feeding three times a day (09:00, 11:30 and 17:00); and F4-feeding four times a day (09:00, 11: 30, 14:00 and 17:00). Experiment 3 lasted 40 days and was conducted in a randomized design to evaluate three periods for the beginning of the feeding transition: WE10:AN for 10 days, followed by 3 days of co-feeding and commercial feed until the end of the experimental period; WE15:AN for 15 days, followed by 3 days of co-feeding and commercial feed; WE20:AN for 20 days, followed by 3 days of co-feeding and commercial feed. The results of this study showed that, for the best development of the larvae, they should receive the feeding protocol 50-100-200 AN/L (P3) until the 20th day of exogenous feeding. From the 21st day, the transition to inert food should begin with 3 days of co-feeding, and feeding during larviculture should be carried out at a frequency of twice a day; this protocol provided a good nutritional status for the larvae, as shown by the histological approach.

RESUMO

The Lebranche mullet Mugil liza is a marine fish of great importance for artisanal and industrial fishing, as well as aquaculture. The use of live feeds during the larviculture phase of marine fish is a significant component of production costs. The present study evaluated the effects of the feeding transition on different larval stages of M. liza, from the combined supply of live feed (Brachionus rotundiformis + Artemia franciscana) and live + inert feed (Artemia franciscana + inert diet) until the weaning phase to only the inert diet. A total of 3240 M. liza larvae (weight 0.0133 ± 0.0062 g and length 0.793 ± 0.160 cm) were distributed among the 12 experimental units (n = 270), resulting in four groups with three replicates each. Treatment groups consisted of feed transition with A. franciscana (enriched metanauplii) to commercial inert feed starting weaning at four different larval ages: 28, 31, 34, and 37 days post hatching. Zootechnical performance indexes and intestinal histomorphometry were evaluated. Mortality, condition factor, and length variation coefficient did not show significant differences between treatments. Final weight, final length, weight gain, and length gain were significantly greater in larvae that started weaning at 31, 34, and 37 days post hatching. Weight coefficient of variation was significantly higher in larvae that started weaning at 28 days (67.51 ± 11.70) compared to 37 days (34.40 ± 7.30). In intestinal histology, villi height (180.3 ± 4.4) was significantly higher in larvae that started weaning at 37 days post hatching. Considering the evidence found in the present study, it is recommended to start weaning M. liza on the 31st day post-hatching, using a 2-day co-feeding protocol (31st and 32nd days). From the 33rd day after hatching, M. liza larvae can receive only commercial feed.

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RESUMO

The daily variations of temperature are one of the main synchronizers of the circadian rhythms. In addition, water temperature influences the embryonic and larval development of fish and directly affects their metabolic processes. The application of thermocycles to fish larvae has been reported to improve growth and the maturation of the digestive system, but their effects on metabolism are poorly understood. The aim of the present study was to evaluate the effect of two different temperature regimes, cycling versus constant, on the daily rhythms of metabolic factors of Nile tilapia (Oreochromis niloticus) larvae. For this purpose, fertilized eggs were divided into two groups: one reared in a 31 °C:25 °C day:night thermocycle (TCY) and another group maintained in a constant 28 °C temperature (CTE). The photoperiod was set to a 12:12 h light/dark cycle. Samples were collected every 4 h during a 24-h cycle on days 4, 8 and 13 post fertilization (dpf). The expression levels of alanine aminotransferase (alt), aspartate aminotransferase (ast), malic enzyme, glucose-6-phosphate dehydrogenase (g6pd), phosphofructokinase (pfk) and pyruvate kinase (pk) were analyzed by qPCR. Results showed that, in 13 dpf animals, most of the genes analyzed (alt, ast, malic, g6pd and pfk) showed daily rhythms in TCY, but not in the group kept at constant temperature, with most acrophases detected during the feeding period. An increase in nutrient metabolism around feeding time can improve food utilization and thus increase larval performance. Therefore, the use of thermocycles is recommended for tilapia larviculture.

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Artemia nauplii are widely used as fish larvae feed due to its beneficial nutritional characteristics for larval development; however, efficient feeding strategies are needed to balance its high costs. Therefore, we evaluated the effects of different densities of Artemia nauplii (100, 250, 500, 750, and 1000 nauplii/post-larvae) on the growth, survival, water quality, and myogenic gene expression of tambaqui (Colossoma macropomum) post-larvae cultivated in a recirculating aquaculture system. After 2 weeks of trial, there was a significant decrease in dissolved oxygen concentration with the increase in nauplii density, but it did not interfere with larval performance and survival. In the first week, larvae fed with fewer than 500 nauplii/post-larvae presented slower growth, while in the second week, larvae fed with 1000 nauplii/post-larvae had the highest final weight and length. Regression analysis suggests that the optimum feeding density of Artemia nauplii during the first week is 411 nauplii/post-larvae, while for the second week, the growth increased proportionally to the feeding densities. The relative expression of the myod, myog, and mstn genes was higher in larvae fed with fewer than 500 nauplii/post-larvae. Although low-growing larvae showed increased expression of myod and myog genes, responsible for muscle hyperplasia and hypertrophy, respectively, mstn expression may have played a significant inhibitory role in larval development. Further research is needed to better determine the effects of the live food on the zootechnical performance and the expression of the myogenic genes in the initial phase of the life cycle of the tambaqui post-larvae.

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The primary aim of this study was to comprehensively evaluate the welfare of Nile tilapia (Oreochromis niloticus) throughout their entire life cycle within aquaculture, spanning from reproduction to slaughter. The methodology was structured to identify welfare indicators closely aligned with the principles of animal freedoms defined by the Farm Animal Council, encompassing environmental, health, nutritional, behavioral, and psychological freedom. Notably, psychological freedom was inherently considered within the behavioral and physical analyses of the animals. To accomplish this, an integrative systematic literature review was conducted to define precise indicators and their corresponding reference values for each stage of tilapia cultivation. These reference values were subsequently categorized using a scoring system that assessed the deviation of each indicator from established ideal (score 1), tolerable (score 2), and critical (score 3) ranges for the welfare of the target species. Subsequently, a laboratory experiment was executed to validate the pre-selected health indicators, specifically tailored for the early life stages of tilapia. This test facilitated an assessment of the applicability of these indicators under operational conditions. Building on the insights gained from this experimentation, partial welfare indices (PWIs) were computed for each assessed freedom, culminating in the derivation of a general welfare index (GWI). Mathematical equations were employed to calculate these indices, offering a quantitative and standardized measure of welfare. This approach equips tilapia farmers and processors with the tools necessary for the continuous monitoring and enhancement of their production systems and stimulate the adoption of more sustainable and ethical practices within the tilapia farming.

RESUMO

The trade of aquarium organisms is growing worldwide. This market depends on a continuous supply of healthy and colorful aquatic animals, but this sector has few initiatives. However, in the last decade, there has been a growing interest in researching captive breeding of these animals, aiming to develop a more sustainable aquarium hobby. Larviculture is an important phase in the cultivation process because the larvae are more sensitive to stress and variations in the bulk of variables, such as temperature, salinity, nutritional management, light intensity and spectrum, and environmental background colors. Because background color could be a promoter variable of proper welfare, we tested whether it affects the endocrine response of tomato clownfish Amphiprion frenatus larvae to an acute stress challenge. We show that background color influences the endocrine stress axis responsiveness in tomato clownfish. When fish were subjected to a standard acute stressor of 61 days after hatching, only fish adapted to white walls increased the whole-body cortisol levels. From the results presented herein, we recommend that white tanks be avoided for A. frenatus larviculture. Both, the less stress level and the good welfare condition of larvae reared in colored tanks may have robust, practical applications since almost all clownfish in the ornamental aquarium trade come from captive breeding.

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Brazilian basslet Gramma brasiliensis is a fish highly appreciated by the marine ornamental industry. There is an increasing interest in the development of a breeding protocol for this species. However, descriptions of the reproductive biology, eggs and larval development are scarce. This study was the first to describe the spawning, eggs and larvae of G. brasiliensis in captivity, including mouth size information. Six spawning events produced egg masses with 27, 127, 600, 750, 850, and 950 eggs. Larger egg masses showed embryos with at least two different developmental stages. Eggs are spherical (∼1.0 mm diameter), held together by filaments entangling chorionic projections. Larvae with fewer than 12 hph (hours post-hatch) presented 3.55 mm standard-length, well developed eyes, fully absorbed yolk sac, an inflated swim bladder and mouth opened. Exogenous feeding on rotifers began within 12 hph. The average mouth width at first feeding was 0.38 mm. The first settled larva was noted by day 21. This information should help to determine appropriate diets and prey-shift time during the larviculture of the species.

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Several species of the planktonic free-living genus Oithona have been successfully used in the larviculture of marine fish and shrimp. However, few studies have been published that allow us to estimate the potential of Oithona nana culture under controlled conditions. This work evaluated the effect of the microalgae Isochrysis galbana and Chaetoceros calcitrans as single (200,000 cells/mL) and mixed diets (100,000 + 100,000 cells/mL) on population and individual growth, ingestion rate, number of spawnings, fertility, development time by stage, and sex ratio of O. nana. We cultured this copepod at 28 ± 0.5 °C, 35 PSU salinity, 125 lux, and 12:12 photoperiod. Results showed that diet had no effect on the final population level (6273-7966 ind/L) or on individual growth, nor on sex ratio, with less males than females. With C. calcitrans, O. nana had a higher filtration rate (57 ng C/ind/day). On the other hand, a mixed diet induced a higher number of spawns (0.4 events/day) and nauplii per spawn (23 ind). Similarly, a single or mixed diet, containing I. galbana, accelerated the development rate by 6.33-7.00 days. We concluded that O. nana can be cultured with both microalgae, indicating its potential use in an intensive system for production. However, more research is required to improve the productivity of O. nana rearing.

RESUMO

Food acceptance in different larval stages of Macrobrachium carcinus was evaluated by investigating the stage at which the ingestion of inert moist diet food begins and by the incidence of Artemia nauplii and inert moist diet in the digestive tract throughout development. Two experiments were carried out: in the first study, the acceptance of the inert diet was evaluated in 60 larvae of each stage (I to XII) fed ad libitum after two hours of fasting. The inert diet was 100% accepted at zoea stage V. In the second study, newly hatched larva was then kept in larval tanks and fed with Artemia nauplii and inert moist diet simultaneously. Fifteen minutes after feeding, 50 specimens of each larval stage were examined and evaluated for the ingestion of these foods. Larvae at stage I did not feed, while larvae at stage II consumed both live and inert food. From the stage of zoea IX, the exclusive consumption of Artemia nauplii was not verified. These data indicate that feeding M. carcinus in larviculture can be initiated at stage II with inert moist diet and Artemia nauplii, and an exclusive supply of inert moist diet from stage IX can be recommended.(AU)

A aceitação alimentar nos diferentes estágios larvais de Macrobrachium carcinus foram avaliadas a partir da investigação da fase em que começa a ingestão de uma dieta inerte úmida e a incidência de náuplios de Artemia e da dieta inerte úmida no trato digestório durante todo o desenvolvimento. Foram realizados dois experimentos: no primeiro, a aceitação da dieta inerte foi avaliada em 60 larvas de cada estágio (I a XII) alimentadas ad libitum após duas horas de jejum. A dieta inerte úmida foi 100% aceita na fase V de zoea. No segundo experimento, larvas recém-eclodidas foram mantidas em tanques larvais e alimentadas com náuplios de Artemia e dieta inerte úmida simultaneamente. Quinze minutos após a alimentação, 50 espécimes de cada estágio larval foram examinados e avaliados em relação à ingestão desses alimentos. Larvas no estágio I não se alimentaram, enquanto larvas no estágio II consumiram alimento vivo e inerte. A partir do estágio de zoea IX o consumo exclusivo de náuplios de Artemia não foi verificado. Esses dados indicam que a alimentação de M. carcinus na larvicultura pode ser iniciada no estágio II, com dieta úmida inerte e náuplios de Artemia, e pode ser recomendado o fornecimento exclusivo de dietas úmidas inertes a partir do estágio IX.(AU)

Assuntos

RESUMO

As the global human population increases, the demand for food grows and, consequently, practices such as aquaculture have become more common. Colossoma macropomum (Cuvier, 1818) is a native Amazonian species, considered to be the second most cultivated fish in the country. We compared the development of post-larval C. macropomum of different ages, submitted to combinations of food management on a commercial production scale. Two experiments tested the delivery of i) 55% crude protein feeding, ii) natural feeding by fertilizing the water and iii) a combination of both during hatchery in concrete tanks (10 m 2) or excavated soil-bottom tanks (4502) subjected to distinct fertilization protocols and storage densities. The weight and length of the post-larvae grown in ponds were greater (p < 2.0x10-16) for the mixed treatment, except during the first week of larvae, in which values were similar (p & 8804; 1.76x10-14) to the fertilization treatment. Concrete tanks with fertilization management without feeding were similar to the mixed treatment (p & 8804; 1.38x10-7); however, during the first week of external larvae production, the growth performance under fertilization treatment was superior to the others. Food management in excavated tanks, when compared to the same management performed in concrete tanks, registered higher averages for the productive variables of C. macropomum cultivated at the density of 200 post-larvae m-2 in all evaluated food strategies. It was verified that post-larvae of C. macropomum did not develop well in the first weeks of life when receiving only formulated diets. The increase in natural food availability through fertilization positively influenced the performance of the species, which can remain without feeding until the second week of life.(AU)

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RESUMO

The effect of fairy shrimp “branchoneta” as the first exogenous feed for tambaqui postlarvae was evaluated. A hundred and eighty larvae were distributed in 12 aquariums, containing 1.5L of water and the stocking density was 10 larvae per liter. The trials lasted for 20 days and postlarvae were submitted to three diets (T1: Commercial feed, T2: branchoneta, and T3: Commercial feed with branchoneta), with a completely randomized design with four replicates for each treatment. During the trials, the water quality parameters were kept within ideal conditions for the species. The tambaqui postlarvae submitted to T2 and T3 showed better survival rates respectively. Regarding the postlarval development, larvae fed with only branchoneta had a better final weight (3.48 mg), daily weight gain (0.14 mg day-1), and the best specific growth rate (8.62%). The results also showed that the tambaqui postlarvae fed with only commercial feed developed less efficiently due to lower rates of survival and growth. The present study indicates that the branchoneta promoted greater development and survival rates of the tambaqui postlarvae and therefore, it presents good potential as a live food for the species.(AU)

Assuntos

RESUMO

Food acceptance in different larval stages of Macrobrachium carcinus was evaluated by investigating the stage at which the ingestion of inert moist diet food begins and by the incidence of Artemia nauplii and inert moist diet in the digestive tract throughout development. Two experiments were carried out: in the first study, the acceptance of the inert diet was evaluated in 60 larvae of each stage (I to XII) fed ad libitum after two hours of fasting. The inert diet was 100% accepted at zoea stage V. In the second study, newly hatched larva was then kept in larval tanks and fed with Artemia nauplii and inert moist diet simultaneously. Fifteen minutes after feeding, 50 specimens of each larval stage were examined and evaluated for the ingestion of these foods. Larvae at stage I did not feed, while larvae at stage II consumed both live and inert food. From the stage of zoea IX, the exclusive consumption of Artemia nauplii was not verified. These data indicate that feeding M. carcinus in larviculture can be initiated at stage II with inert moist diet and Artemia nauplii, and an exclusive supply of inert moist diet from stage IX can be recommended.

A aceitação alimentar nos diferentes estágios larvais de Macrobrachium carcinus foram avaliadas a partir da investigação da fase em que começa a ingestão de uma dieta inerte úmida e a incidência de náuplios de Artemia e da dieta inerte úmida no trato digestório durante todo o desenvolvimento. Foram realizados dois experimentos: no primeiro, a aceitação da dieta inerte foi avaliada em 60 larvas de cada estágio (I a XII) alimentadas ad libitum após duas horas de jejum. A dieta inerte úmida foi 100% aceita na fase V de zoea. No segundo experimento, larvas recém-eclodidas foram mantidas em tanques larvais e alimentadas com náuplios de Artemia e dieta inerte úmida simultaneamente. Quinze minutos após a alimentação, 50 espécimes de cada estágio larval foram examinados e avaliados em relação à ingestão desses alimentos. Larvas no estágio I não se alimentaram, enquanto larvas no estágio II consumiram alimento vivo e inerte. A partir do estágio de zoea IX o consumo exclusivo de náuplios de Artemia não foi verificado. Esses dados indicam que a alimentação de M. carcinus na larvicultura pode ser iniciada no estágio II, com dieta úmida inerte e náuplios de Artemia, e pode ser recomendado o fornecimento exclusivo de dietas úmidas inertes a partir do estágio IX.

Assuntos

RESUMO

The effect of fairy shrimp “branchoneta” as the first exogenous feed for tambaqui postlarvae was evaluated. A hundred and eighty larvae were distributed in 12 aquariums, containing 1.5L of water and the stocking density was 10 larvae per liter. The trials lasted for 20 days and postlarvae were submitted to three diets (T1: Commercial feed, T2: branchoneta, and T3: Commercial feed with branchoneta), with a completely randomized design with four replicates for each treatment. During the trials, the water quality parameters were kept within ideal conditions for the species. The tambaqui postlarvae submitted to T2 and T3 showed better survival rates respectively. Regarding the postlarval development, larvae fed with only branchoneta had a better final weight (3.48 mg), daily weight gain (0.14 mg day-1), and the best specific growth rate (8.62%). The results also showed that the tambaqui postlarvae fed with only commercial feed developed less efficiently due to lower rates of survival and growth. The present study indicates that the branchoneta promoted greater development and survival rates of the tambaqui postlarvae and therefore, it presents good potential as a live food for the species.

Assuntos

RESUMO

As the global human population increases, the demand for food grows and, consequently, practices such as aquaculture have become more common. Colossoma macropomum (Cuvier, 1818) is a native Amazonian species, considered to be the second most cultivated fish in the country. We compared the development of post-larval C. macropomum of different ages, submitted to combinations of food management on a commercial production scale. Two experiments tested the delivery of i) 55% crude protein feeding, ii) natural feeding by fertilizing the water and iii) a combination of both during hatchery in concrete tanks (10 m 2) or excavated soil-bottom tanks (4502) subjected to distinct fertilization protocols and storage densities. The weight and length of the post-larvae grown in ponds were greater (p < 2.0x10-16) for the mixed treatment, except during the first week of larvae, in which values were similar (p & 8804; 1.76x10-14) to the fertilization treatment. Concrete tanks with fertilization management without feeding were similar to the mixed treatment (p & 8804; 1.38x10-7); however, during the first week of external larvae production, the growth performance under fertilization treatment was superior to the others. Food management in excavated tanks, when compared to the same management performed in concrete tanks, registered higher averages for the productive variables of C. macropomum cultivated at the density of 200 post-larvae m-2 in all evaluated food strategies. It was verified that post-larvae of C. macropomum did not develop well in the first weeks of life when receiving only formulated diets. The increase in natural food availability through fertilization positively influenced the performance of the species, which can remain without feeding until the second week of life.

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RESUMO

Resumen Entre los más importantes peces del río Meta se encuentra Prochilodus mariae (bocachico llanero o coporo), tanto por su mayor tamaño dentro de los bocachicos de la cuenca, como por su aporte a la biomasa trófica y de las pesquerías de la región. En el presente trabajo se evaluó el régimen alimenticio de poslarvas (inicio de la alimentación exógena) del coporo Prochilodus mariae, hasta el inicio de la fase de alevino (aletas completas y cuerpo con escamas), en condiciones simuladas durante los primeros 30 días de alimentación exógena. Los estanques en tierra del IALL, asignados para el desarrollo de este trabajo, fueron abonados orgánicamente con (bovinaza y heno) teniendo en cuenta las condiciones que suceden cada año, a las entradas de aguas en las áreas de inundación de los afluentes, los que fueron sembrados con larvas obtenidas por reproducción inducida a densidad de veinte larvas / m2 y con el 80% de su saco vitelino absorbido. Cada dos días, durante 30 días, a las 8:00 h, fueron colectadas poslarvas junto con las muestras de zooplantcton y fitoplancton y fijados en formol bufferado al 4%. Los índices de frecuencia (IF) de los contenidos estomacales de siete poslarvas/estanque y los ítems alimenticios como oferta hallados en aguas y perifiton fueron evaluados. Los análisis se realizaron con un total de 156 ejemplares que oscilan entre intervalos de 6-8.99; 9-17.99; 18-26.99; 27-35.99; 36-44.99; 45-47.99 mm de longitud total. Las poslarvas del primer intervalo exploran organismos relacionados con el perifiton principalmente bacterias, protozoos y algas en este primer muestreo se caracterizó porque el 66.7% de las poslarvas presentaron estómagos vacíos. En las poslarvas del segundo intervalo el IF de los contenidos mostró una tendencia por el consumo de organismos pelágicos con preferencia por los cladóceros. En el último intervalo los alevinos inician el consumo de detritos (materia orgánica particulada, bacterias, hongos) y otras formas del fitoplancton cercano a las paredes y fondo del estanque.

Abstract Prochilodus mariae (bocachico llanero or coporo) is amongst the most important fish in the Meta River (a major left tributary of the Orinoco River); along with being the largest of the Prochilodus species in the river basin, flannel-mouth characiforms contribute greatly to the dynamics of the region's food chain and fisheries. This work was aimed at assessing Prochilodus mariae post-larvae feeding habits during their first thirty days of exogenous feeding until the beginning of the alevin stage. Simulations were made in the Instituto de Acuicultura de los Llanos (IALL) facilities' earthen fish ponds to closely resemble the fishes' natural annual water and feeding conditions. The ponds had been organically fertilised with cattle manure and hay and were then periodically inundated and drained to simulate the Meta River's tributaries natural/annual floodplains or areas that are periodically inundated by high water levels. The ponds were stocked with larvae obtained by artificial spawning at twenty larvae/m2 density when around 80% of their yolk sacs had been absorbed. Post-larvae and pond water samples containing zooplankton and phytoplankton were collected at 8 am every other day for 30 days and fixed in 4% buffered formalin. Seven post-larvae/pond stomach/gut contents (frequency of fullness index - FI) were analysed from 156 specimens divided into size intervals ranging from 6-8.99, 9-17.99, 18-26.99, 27-35.99, 36-44.99 and 45-47.99 mm in length. Food items' frequency of abundance (i.e. supply) in the pond water and periphyton were estimated. First-size interval post-larvae explore periphyton-related organisms for their food source (mainly bacteria, protozoans and algae). This first sampling was characterised by 66.7% of the post-larvae having empty stomachs. Second-size interval post-larvae FI tended reflect the consumption of pelagic organisms, having a preference for microcrustaceans (cladocerans and copepods). The longest alevins (45-47.99 mm long) started consuming detritus (particulate organic matter, bacteria and fungi) and other forms of phytoplankton close to the sides and bottom of the fishponds.

Resumo Entre os peixes mais importantes do rio Meta encontra-se Prochilodus mariae (bocachico llanero ou coporo), devido a ser dos maiores bocachicos da bacia, assim como a sua contribuição para a biomassa trófica e pesca da região. O presente trabalho pretende avaliar a dieta das pós-larvas do coporo Prochilodus mariae, até ao início da fase de alevinos em condições simuladas durante os primeiros trinta dias de alimentação exógena. Os estanques do IALL destinados ao desenvolvimento deste trabalho, foram fertilizados organicamente com (esterco bovino e feno) atendendo às condições que ocorrem a cada ano, na entrada de água nas áreas de alagamento dos afluentes, que foram semeados com larvas obtidas por reprodução induzida na densidade de vinte larvas / m2 e com 80% do saco vitelino absorvido. A cada dois dias, durante 30 dias, às 8:00 da manhã, as pós-larvas eram recolhidas juntamente com a água, e fixadas em formalina tamponada a 4%. Foram avaliados os índices de frequência (IF) do conteúdo estomacal de sete pós-larvas/tanque e itens alimentares encontrados nas águas e perifiton. As análises foram realizadas com um total de 156 espécimes entre 6-8,99; 9-17,99; 18-26,99; 27-35:99; 36-44,99; 45-47,99mm de comprimento total. As pós-larvas do primeiro intervalo exploram organismos relacionados com o perifiton principalmente bactérias, protozoários e algas, esta primeira amostragem foi caracterizada porque 66,7% das pós-larvas apresentavam estômagos vazios. Nas pós-larvas do segundo intervalo o IF do conteúdo estomacal mostrou uma tendência para o consumo de organismos pelágicos com preferência pelos cladóceros. No último intervalo, os alevinos começam a consumir detritos (partículas orgânicas, bactérias, fungos) e formas de fitoplâncton ligadas às superfícies do substrato (feno) e ao fundo do tanque.

RESUMO

A piscicultura brasileira está em expansão no Brasil, um setor que cresce a cada ano, porém na fase da larvicultura onde os peixes são inseridos em viveiros escavados, os mesmos em decorrência da sua vulnerabilidade e tamanho ficam susceptíveis à doenças e predadores. Dentre os predadores da piscicultura estão os insetos aquáticos, no qual os da ordem Odonata são considerados os principais. A ordem Odonata apesar de causar a predação na larvicultura de peixes é importante, pois desempenham papéis importantes no ambiente aquático e são considerados bioindicadores. Mesmo com essa importância, o piscicultor para resolver esses problemas, acaba por despejar defensivos agrícolas ou proporcionar a calagem intensa que pode trazer consequências graves tanto para os peixes como para a qualidade da água, diante disso seria necessário pensar em sustentabilidade na piscicultura com um manejo ou um controle natural desses predadores para que não haja impactos ambientais. Portanto, o objetivo desse trabalho foi abordar o histórico da piscicultura brasileira, os problemas enfrentados na larvicultura por predação de Odonata e oferecer alternativas sustentáveis de controle.(AU)

Brazilian fish farming is expanding in Brazil, presenting exceptional annual growth. However, during the larviculture phase, where fish is inserted in excavated ponds, due to their vulnerability and size, they become susceptible to diseases and predators. Aquatic insects feature among the predators in fish farming, with the Odonata order being the most prominent. Despite their predatory action during the larvae phase of fish, the Odonata order plays an important role in the aquatic environment and is considered as bioindicators. Despite its importance, to solve these problems, fish farmers end up using agrochemicals or providing intense liming, which can have serious consequences for both fish and water quality. Therefore, in face of this scenario, further studies on fish farming sustainability with management or control of those predators would be important in order to mitigate the environmental impacts. Thus, the objective of this paper was to address the history of Brazilian fish farming, the problems faced in larviculture due to predation by Odonata and to offer sustainable control alternatives.(AU)

La piscicultura brasileña se está expandiendo en Brasil, un sector que crece cada año, sin embargo, en la fase de larvicultura donde los peces se insertan en estanques excavados, por su vulnerabilidad y tamaño se quedan susceptibles a enfermedades y depredadores. Entre los depredadores de la piscicultura se encuentran los insectos acuáticos, los del orden Odonata son considerados los principales. El orden Odonata, a pesar de causar depredación en la larvicultura de peces es importante porque desempeñan papeles valiosos en el medio acuático y se consideran bioindicadores. Mismo con esa importancia, el piscicultor para solucionar esos problemas, acaba tirando plaguicidas o proporcionando un encalado intenso que puede traer graves consecuencias tanto para los peces como para la calidad del agua, considerando que sería necesario pensar en la sostenibilidad de la piscicultura con un manejo o control natural de esos depredadores para que no haya impactos ambientales. Por lo tanto, el objetivo de ese estudio ha sido abordar el histórico de la piscicultura brasileña, los problemas que enfrenta la larvicultura debido a la depredación de Odonata y ofrecer alternativas de control sostenibles.(AU)

Assuntos

RESUMO

A piscicultura brasileira está em expansão no Brasil, um setor que cresce a cada ano, porém na fase da larvicultura onde os peixes são inseridos em viveiros escavados, os mesmos em decorrência da sua vulnerabilidade e tamanho ficam susceptíveis à doenças e predadores. Dentre os predadores da piscicultura estão os insetos aquáticos, no qual os da ordem Odonata são considerados os principais. A ordem Odonata apesar de causar a predação na larvicultura de peixes é importante, pois desempenham papéis importantes no ambiente aquático e são considerados bioindicadores. Mesmo com essa importância, o piscicultor para resolver esses problemas, acaba por despejar defensivos agrícolas ou proporcionar a calagem intensa que pode trazer consequências graves tanto para os peixes como para a qualidade da água, diante disso seria necessário pensar em sustentabilidade na piscicultura com um manejo ou um controle natural desses predadores para que não haja impactos ambientais. Portanto, o objetivo desse trabalho foi abordar o histórico da piscicultura brasileira, os problemas enfrentados na larvicultura por predação de Odonata e oferecer alternativas sustentáveis de controle.(AU)

Brazilian fish farming is expanding in Brazil, presenting exceptional annual growth. However, during the larviculture phase, where fish is inserted in excavated ponds, due to their vulnerability and size, they become susceptible to diseases and predators. Aquatic insects feature among the predators in fish farming, with the Odonata order being the most prominent. Despite their predatory action during the larvae phase of fish, the Odonata order plays an important role in the aquatic environment and is considered as bioindicators. Despite its importance, to solve these problems, fish farmers end up using agrochemicals or providing intense liming, which can have serious consequences for both fish and water quality. Therefore, in face of this scenario, further studies on fish farming sustainability with management or control of those predators would be important in order to mitigate the environmental impacts. Thus, the objective of this paper was to address the history of Brazilian fish farming, the problems faced in larviculture due to predation by Odonata and to offer sustainable control alternatives.(AU)

La piscicultura brasileña se está expandiendo en Brasil, un sector que crece cada año, sin embargo, en la fase de larvicultura donde los peces se insertan en estanques excavados, por su vulnerabilidad y tamaño se quedan susceptibles a enfermedades y depredadores. Entre los depredadores de la piscicultura se encuentran los insectos acuáticos, los del orden Odonata son considerados los principales. El orden Odonata, a pesar de causar depredación en la larvicultura de peces es importante porque desempeñan papeles valiosos en el medio acuático y se consideran bioindicadores. Mismo con esa importancia, el piscicultor para solucionar esos problemas, acaba tirando plaguicidas o proporcionando un encalado intenso que puede traer graves consecuencias tanto para los peces como para la calidad del agua, considerando que sería necesario pensar en la sostenibilidad de la piscicultura con un manejo o control natural de esos depredadores para que no haya impactos ambientales. Por lo tanto, el objetivo de ese estudio ha sido abordar el histórico de la piscicultura brasileña, los problemas que enfrenta la larvicultura debido a la depredación de Odonata y ofrecer alternativas de control sostenibles.(AU)

Assuntos

RESUMO

The aim of the present study was to evaluate the zootechnical performance, intestinal mucosa, and reaction to infestation by the parasite Ichthyophthirius multifiliis in jundiá Rhamdia quelen larvae supplemented with Mentha piperita essential oil or sodium butyrate in their diets. Five diets were used over 30 days: diet free of additive inclusion, 0% (control); inclusion of 1% or 2% of M. piperita essential oil: EO1% and EO2%, respectively; and inclusion of 0.25% or 0.50% of sodium butyrate: SB0.25% and SB0.50%, respectively. The different diets were not able to inhibit I. multifiliis infestation. Supplementation with SB0.50% in their diets presented better performance in all zootechnical parameters analyzed, including a 54% increase in final weight and 70% in survival, and increased (P 0.05) both the villi width and the amount of goblet cells present in the intestinal mucosa by approximately 50%. In view of these results, dietary supplementation of R. quelen larvae with 0.50% sodium butyrate for 30 days is recommended.(AU)

O objetivo do presente estudo foi avaliar o desempenho zootécnico, a mucosa intestinal, a resistência ao estresse e a reação à infestação pelo parasita Ichthyophthirius multifiliis em larvas de jundiá Rhamdia quelen suplementadas com óleo essencial de Mentha piperita ou butirato de sódio em suas dietas. Foram utilizadas cinco dietas por 30 dias: dieta livre de inclusão de aditivos, 0% (controle); inclusão de 1% ou 2% de óleo essencial de M. piperita, EO1% e EO2%, respectivamente; e inclusão de 0,25% ou 0,50% de butirato de sódio, SB0.25% e SB0.50%, respectivamente. As diferentes dietas não foram capazes de inibir a infestação por I. multifiliis. A suplementação com SB0.50% em suas dietas apresentou melhor desempenho em todos os parâmetros zootécnicos analisados, incluindo um aumento do peso final em 54% e a sobrevivência em 70%, e aumentou (P 0,05) a largura das vilosidades e a quantidade de células caliciformes presentes na mucosa intestinal em aproximadamente 50%. Em vista desses resultados, recomenda-se a suplementação dietética de larvas de R. quelen com butirato de sódio a 0,50% por 30 dias.(AU)

Assuntos

RESUMO

ABSTRACT: The aim of the present study was to evaluate the zootechnical performance, intestinal mucosa, and reaction to infestation by the parasite Ichthyophthirius multifiliis in jundiá Rhamdia quelen larvae supplemented with Mentha piperita essential oil or sodium butyrate in their diets. Five diets were used over 30 days: diet free of additive inclusion, 0% (control); inclusion of 1% or 2% of M. piperita essential oil: EO1% and EO2%, respectively; and inclusion of 0.25% or 0.50% of sodium butyrate: SB0.25% and SB0.50%, respectively. The different diets were not able to inhibit I. multifiliis infestation. Supplementation with SB0.50% in their diets presented better performance in all zootechnical parameters analyzed, including a 54% increase in final weight and 70% in survival, and increased (P<0.05) both the villi width and the amount of goblet cells present in the intestinal mucosa by approximately 50%. In view of these results, dietary supplementation of R. quelen larvae with 0.50% sodium butyrate for 30 days is recommended.

RESUMO: O objetivo do presente estudo foi avaliar o desempenho zootécnico, a mucosa intestinal, a resistência ao estresse e a reação à infestação pelo parasita Ichthyophthirius multifiliis em larvas de jundiá Rhamdia quelen suplementadas com óleo essencial de Mentha piperita ou butirato de sódio em suas dietas. Foram utilizadas cinco dietas por 30 dias: dieta livre de inclusão de aditivos, 0% (controle); inclusão de 1% ou 2% de óleo essencial de M. piperita, EO1% e EO2%, respectivamente; e inclusão de 0,25% ou 0,50% de butirato de sódio, SB0.25% e SB0.50%, respectivamente. As diferentes dietas não foram capazes de inibir a infestação por I. multifiliis. A suplementação com SB0.50% em suas dietas apresentou melhor desempenho em todos os parâmetros zootécnicos analisados, incluindo um aumento do peso final em 54% e a sobrevivência em 70%, e aumentou ​​(P<0,05) a largura das vilosidades e a quantidade de células caliciformes presentes na mucosa intestinal em aproximadamente 50%. Em vista desses resultados, recomenda-se a suplementação dietética de larvas de R. quelen com butirato de sódio a 0,50% por 30 dias.