Manuel V. Vidal Jr. - Academia.edu (original) (raw)

Papers by Manuel V. Vidal Jr.

Journal of Agricultural Science

Fish feed represents between 50% and 70% of intensive aquaculture production costs. In this conte... more Fish feed represents between 50% and 70% of intensive aquaculture production costs. In this context, the present study aimed to evaluate the economic viability of the production of Nile tilapia under a diet with cassava residues in it. To evaluate the economic efficiency in relation to the inclusion of residues in the tilapia feed, the approximate cost of feed per kilogram of live weight (CMR) gained during the experimental period was determined, and later the cash flow of the production was raised for analysis of indicators: NPV (Net Present Value), CBI (Cost Benefit Rate), and IRR (Internal Rate of Return) submitted to different discount rates from existing financing sources in the region. It was found that tilapia under the diet with the inclusion of tapioca sweep in the diet, showed greater economic efficiency, and consequently higher NPV (R $ 4,583.33), IRR (15%) and CBR (1.17). In this sense, the viability analysis showed that cassava residues in diets of tilapia diets, indica...

A piscicultura ornamental desperta interesse pelo alto valor agregado de seus produtos e, dentre ... more A piscicultura ornamental desperta interesse pelo alto valor agregado de seus produtos e, dentre as espécies cultivadas, o acará-bandeira destaca-se pela beleza exótica e por ter as etapas de sua produção já, razoavelmente, dominadas. Estes aspectos justificam estudos sobre estas espécies, em especial os concernentes à sua reprodução e desenvolvimento embrionário e larval. O triclorfon é um composto organofosforado utilizado para controle de pragas na agricultura e parasitos externos em animais domésticos e, na piscicultura, é utilizado para controle de ectoparasitas causadores de enfermidades. Estudos acerca da utilização deste composto e seus efeitos no ambiente são de extrema importância principalmente no que se refere à contaminação de recursos hídricos por uso inadequado gerando impacto em ecossistemas aquáticos e sua biota. Para realização do experimento serão utilizados ovos de desovas naturais de Pterophyllum scalare oriundos do plantel do setor de aqüicultura do CCTA/ UENF....

A piscicultura ornamental é um ramo da aquicultura de bastante evidência. Dentre as espécies de p... more A piscicultura ornamental é um ramo da aquicultura de bastante evidência. Dentre as espécies de peixes cultivadas comercialmente, tem tido destaque a Melanotênia boesemani, o que se dá principalmente devido à coloração diferenciada, que divide o peixe em uma metade anterior azul e posterior de cor amarelo-alaranjado, tornando-o muito atrativo para a utilização em aquários e lagos. Diante do grande potencial de produção e alto valor de mercado, estudos relacionados à espécie se tornam relevantes, em especial os concernentes à reprodução e desenvolvimento embrionário e larval que quando bem elucidados podem aumentar o potencial produtivo da espécie. Foram utilizadas desovas naturais de M. boesemani oriundas do plantel do setor de aquicultura da UENF. Em cada aquário com reprodutores, foram colocados aguapés (Echhornia crasipes), e estes observados até que ocorresse desova. Os ovos foram contados e levados para incubadoras com temperaturas de 32°C, 29°C, 26°C ou 23°C mantidas com a uti...

Brazilian journal of biology = Revista brasleira de biologia, 2021

The objective of this study was to evaluate the properties of garlic as a growth promoter in larv... more The objective of this study was to evaluate the properties of garlic as a growth promoter in larvae of angelfish Pterophyllum scalare and its benefits during transport of juveniles of this species. The experiment was conducted in recirculation aquaculture system, consisting of 20 tanks of 40 L equipped with independent water input and output. We used 1,400 larvae distributed among five treatments, with four repetitions, which totaled 20 experimental units. The treatments were 0, 50, 100, 200, and 400 mg of garlic extract per kilo of feed. The results showed that the inclusion of levels of garlic extract in the feed did not significantly effect the fish's development or their transport. Neither did the inclusion of levels of garlic extract affect the survival of the larvae during the trial period. New research with extracts of higher dosages should be performed to elucidate the effect of garlic extract as a growth promoter.

O experimento foi conduzido com o objetivo de avaliar a utilizacao do alho na alimentacao de acar... more O experimento foi conduzido com o objetivo de avaliar a utilizacao do alho na alimentacao de acara bandeira como promotor de crescimento. Foram utilizados 75 peixes, distribuidos em cinco tratamentos com tres repeticoes. Os tratamentos foram: 0,0%, 0,01%, 0,1%, 0,5% e 1,0% de extrato de alho na racao. Nao foram observados efeitos significativos dos tratamentos sobre as caracteristicas avaliadas. Os peixes apresentaram desempenho normal, sugerindo que as condicoes nas quais foram desenvolvidos os experimentos nao foram adequadas para obter respostas.

Acta Amazonica, 2017

In an experiment performed to characterize the reproductive behavior of the discus fish in captiv... more In an experiment performed to characterize the reproductive behavior of the discus fish in captivity, couple formation with two females was observed. The observations were carried out in captivity, based on ad libitum methodology. Adult individuals were allowed to naturally form couples. The couple formation was considered when individuals performed the substrate cleaning behavior. Fifteen couples were selected. The eggs of three couples did not initiate embryonic development and became infeasible within three days after spawning. We found that these spawnings belonged to all-female couples. The sex of the individuals in same-sex couples was confirmed through subsequent couple formation and spawning of fertile eggs with known males. Eggs were deposited by one or both females in the same-sex couples. Double spawnings were larger and differentially colored. The motivations that lead individuals of the same sex to form couples in this species are still unknown.

Brazilian Journal of Veterinary Research and Animal Science, 2007

O objetivo deste trabalho foi verificar a viabilidade da utilização do espermatócrito para estima... more O objetivo deste trabalho foi verificar a viabilidade da utilização do espermatócrito para estimar a concentração espermática do sêmen de piabanha. Os exemplares (n=29) de piabanha Brycon insignis foram hipofisados, sendo posteriormente realizada a coleta de sêmen. O espermatócrito foi determinado utilizando-se micro-centrífuga de tubos capilares. A concentração espermática foi verificada por contagem em câmara de Neubauer, após diluição. A concentração espermática verificada (média±desvio padrão) foi de 24,38 ± 3,84 x 10(9) espermatozóides / mL, e o espermatócrito foi de 16,14±5,20%. A equação de regressão: v = 14,01.10(9) + 0,6428.10(9).X foi significativa (P<0,01) e apresentou R² ajustado = 0,75. Deste modo, é possível estimar a concentração através da determinação do espermatócrito.

Acta Amazonica, 2016

The blue discus (Symphysodon aequifasciatus) is often sold for ornamental purposes. It is a neotr... more The blue discus (Symphysodon aequifasciatus) is often sold for ornamental purposes. It is a neotropical cichlid from South America, which is native to the rivers of the Amazon basin of Brazil, Peru and Colombia. The purpose of this study was to characterize the reproductive behavior of S. aequifasciatus and identify features that can later be used by breeders to facilitate the handling and reproduction of this species in captivity. The experiment was divided into two stages: the first dealt with partner selection and couple formation to observe the behaviors of territoriality, pursuing, fleeing, biting, stay, protecting and cleaning of the substrate. The second stage documented mating behavior, nesting and parental care, to observe vibration, spawning, permanence with the offspring, aeration of eggs, cleaning of spawning, color change and shift-taking in parental care. The results of the study allowed identifying disputes for and establishment of territory, as well as the selection ...

Zootecnia Tropical, Oct 1, 2007

Realizing the need for more clarification on the status of research on Fish Nutrition, this work ... more Realizing the need for more clarification on the status of research on Fish Nutrition, this work aimed to do a bibliometric study, using the Scopus database, using the entries Fish Nutrition and Enzyme Activity, both in Brazil and worldwide. The results were presented stratified, showing the tendencies of publication in the specific knowledge area. The research in the Scopus database was performed on January 2012, taking into account the historical series from 1999 to 2010. The data obtained from the research were: number of publications per year or historic series, publication by author, by area, by journal, by institution, by country and the language of the publication. The analysis of the concentration was performed by the comparison of the number of publication of the 10 main contributors (countries, knowledge area, authors, institutions and journal) in relation to the total of publications from Scopus database. For a temporal analysis, were used exponential regression equations...

Zygote, 2015

SummaryThe present study aimed to provide data on the time required for Melanotaenia boesemani to... more SummaryThe present study aimed to provide data on the time required for Melanotaenia boesemani to complete embryonic development, and to investigate the influence that incubation at different temperatures caused in this species. The effects of temperature on the time and hatching rate are presented, as well as information related to embryonic development stages. After fertilization, the eggs were kept in incubators at 23, 26, 29 or 32°C and observed at predetermined times until the moment of hatching. Stages of development were identified and classified according to morphological and physiological characteristics. Oil droplets were visualized inside the eggs as well as filament adhesion present at the chorion. Embryonic development was similar to that observed in other species of the genus Melanotaenia with hatching and faster development in higher temperatures.

Revista Brasileira de Zootecnia, 2004

Foram realizados dois experimentos com o objetivo de comparar técnicas de digestibilidade de nutr... more Foram realizados dois experimentos com o objetivo de comparar técnicas de digestibilidade de nutrientes de alimentos para peixes, com o uso dos indicadores externos (óxido crômico e carbonato de bário) e internos (cinza insolúvel em ácido, cinza insolúvel em detergente ácido, fibra bruta e fibra detergente ácido) e com a técnica de determinação direta. Tambaquis com 100 g receberam, no primeiro experimento, fubá de milho e, no segundo, farelo de soja. O óxido crômico e o carbonato de bário são indicadores externos efetivos para estimar os coeficientes de digestibilidade dos alimentos para tambaquis. A fibra bruta e a fibra detergente ácido apresentaram baixa recuperação e não estimaram de forma consistente os coeficientes de digestibilidade dos alimentos para tambaquis, subestimando-os. A cinza insolúvel em ácido e a cinza insolúvel em detergente ácido apresentaram alta porcentagem de recuperação e estimaram de forma consistente os coeficientes de digestibilidade dos alimentos para ...

Revista Brasileira de Ciência Veterinária, 1997

Ciência Animal Brasileira, 2011

Revista Ciência Agronômica, 2015

Ciência Animal Brasileira, 2010

Pesquisa Veterinária Brasileira, 2014

Peixes cultivados mostram-se altamente sensíveis a dietas deficientes em ácido ascórbico com sina... more Peixes cultivados mostram-se altamente sensíveis a dietas deficientes em ácido ascórbico com sinais clínicos que afetam o desempenho e a comercialização por provocar deformidades. Com objetivo de conhecer os níveis mínimos para a melanotênia-maçã, foram testadas seis rações isoaminoacídicas e isocalóricas com níveis variados de vitamina C ativa. Ao final dos 42 dias experimentais, 36 peixes foram analisados histologicamente quanto à porcentagem de tecido conjuntivo e fibras musculares a fim de determinar a influência da porcentagem de Vitamina C nesses índices. Apesar de as médias serem estatisticamente iguais do ponto de vista quantitativo, qualitativamente os níveis mais altos de vitamina C possibilitaram melhor estrutura tecidual. A desestruturação do tecido muscular é um indicativo da deficiência alimentar com ácido ascórbico.

Ciência Animal Brasileira, 2011

Neotropical Ichthyology, 2012

In the present study we analysed the proximate-composition and caloric values of the preferred pr... more In the present study we analysed the proximate-composition and caloric values of the preferred prey consumed by ribbonfish, Trichiurus lepturus L. 1758 (adult females), that are distributed in the inner continental shelf from northern Rio de Janeiro State, southeastern Brazil (~22ºS), assessing the potential of nutritional and energetic approach as a tool to understand the feeding selective pattern of this marine top carnivore. The preferred prey of this predator composed of fish co-specifics, Pellona harroweri, Chirocentrodon bleekerianus, Lycengraulis grossidens, Peprilus paru, squid Doryteuthis plei, and shrimp Xiphopenaeus kroyeri were collected from 2007 to 2010 for proximate-composition (water, protein, lipid, ash, and carbohydrate) and caloric value analyses. The correspondence analysis showed that protein is the main component in the prey species (61.32% of variance explained), standing out from the other nutrients. Lipid has the highest percentage related to L. grossidens, ...

Zygote, 2014

SummaryThe aim of this study was to describe the embryonic and larval development of discus fish ... more SummaryThe aim of this study was to describe the embryonic and larval development of discus fish (Symphysodon aequifasciatus), and to determine the time required, hours post fertilization (hpf), for the emergence of various structures. To describe embryonic and larval stages, observations were made at regular periods under an optical microscope and images were taken with a digital camera attached to a microscope. The average temperature reached in the experimental tank was 27.9°C. Important facts in embryonic and larval development are described, such as the closure of the blastopore, which occurred at 31.5 hpf; a period of eruption, which occurred at 58.5 hpf; and a mouth opening, which occurred at 90.5 hpf; and larvae that exhibited oriented swimming and eating exogenous food at 136.5 hpf.

Journal of Agricultural Science

Fish feed represents between 50% and 70% of intensive aquaculture production costs. In this conte... more Fish feed represents between 50% and 70% of intensive aquaculture production costs. In this context, the present study aimed to evaluate the economic viability of the production of Nile tilapia under a diet with cassava residues in it. To evaluate the economic efficiency in relation to the inclusion of residues in the tilapia feed, the approximate cost of feed per kilogram of live weight (CMR) gained during the experimental period was determined, and later the cash flow of the production was raised for analysis of indicators: NPV (Net Present Value), CBI (Cost Benefit Rate), and IRR (Internal Rate of Return) submitted to different discount rates from existing financing sources in the region. It was found that tilapia under the diet with the inclusion of tapioca sweep in the diet, showed greater economic efficiency, and consequently higher NPV (R $ 4,583.33), IRR (15%) and CBR (1.17). In this sense, the viability analysis showed that cassava residues in diets of tilapia diets, indica...

A piscicultura ornamental desperta interesse pelo alto valor agregado de seus produtos e, dentre ... more A piscicultura ornamental desperta interesse pelo alto valor agregado de seus produtos e, dentre as espécies cultivadas, o acará-bandeira destaca-se pela beleza exótica e por ter as etapas de sua produção já, razoavelmente, dominadas. Estes aspectos justificam estudos sobre estas espécies, em especial os concernentes à sua reprodução e desenvolvimento embrionário e larval. O triclorfon é um composto organofosforado utilizado para controle de pragas na agricultura e parasitos externos em animais domésticos e, na piscicultura, é utilizado para controle de ectoparasitas causadores de enfermidades. Estudos acerca da utilização deste composto e seus efeitos no ambiente são de extrema importância principalmente no que se refere à contaminação de recursos hídricos por uso inadequado gerando impacto em ecossistemas aquáticos e sua biota. Para realização do experimento serão utilizados ovos de desovas naturais de Pterophyllum scalare oriundos do plantel do setor de aqüicultura do CCTA/ UENF....

A piscicultura ornamental é um ramo da aquicultura de bastante evidência. Dentre as espécies de p... more A piscicultura ornamental é um ramo da aquicultura de bastante evidência. Dentre as espécies de peixes cultivadas comercialmente, tem tido destaque a Melanotênia boesemani, o que se dá principalmente devido à coloração diferenciada, que divide o peixe em uma metade anterior azul e posterior de cor amarelo-alaranjado, tornando-o muito atrativo para a utilização em aquários e lagos. Diante do grande potencial de produção e alto valor de mercado, estudos relacionados à espécie se tornam relevantes, em especial os concernentes à reprodução e desenvolvimento embrionário e larval que quando bem elucidados podem aumentar o potencial produtivo da espécie. Foram utilizadas desovas naturais de M. boesemani oriundas do plantel do setor de aquicultura da UENF. Em cada aquário com reprodutores, foram colocados aguapés (Echhornia crasipes), e estes observados até que ocorresse desova. Os ovos foram contados e levados para incubadoras com temperaturas de 32°C, 29°C, 26°C ou 23°C mantidas com a uti...

Brazilian journal of biology = Revista brasleira de biologia, 2021

The objective of this study was to evaluate the properties of garlic as a growth promoter in larv... more The objective of this study was to evaluate the properties of garlic as a growth promoter in larvae of angelfish Pterophyllum scalare and its benefits during transport of juveniles of this species. The experiment was conducted in recirculation aquaculture system, consisting of 20 tanks of 40 L equipped with independent water input and output. We used 1,400 larvae distributed among five treatments, with four repetitions, which totaled 20 experimental units. The treatments were 0, 50, 100, 200, and 400 mg of garlic extract per kilo of feed. The results showed that the inclusion of levels of garlic extract in the feed did not significantly effect the fish's development or their transport. Neither did the inclusion of levels of garlic extract affect the survival of the larvae during the trial period. New research with extracts of higher dosages should be performed to elucidate the effect of garlic extract as a growth promoter.

O experimento foi conduzido com o objetivo de avaliar a utilizacao do alho na alimentacao de acar... more O experimento foi conduzido com o objetivo de avaliar a utilizacao do alho na alimentacao de acara bandeira como promotor de crescimento. Foram utilizados 75 peixes, distribuidos em cinco tratamentos com tres repeticoes. Os tratamentos foram: 0,0%, 0,01%, 0,1%, 0,5% e 1,0% de extrato de alho na racao. Nao foram observados efeitos significativos dos tratamentos sobre as caracteristicas avaliadas. Os peixes apresentaram desempenho normal, sugerindo que as condicoes nas quais foram desenvolvidos os experimentos nao foram adequadas para obter respostas.

Acta Amazonica, 2017

In an experiment performed to characterize the reproductive behavior of the discus fish in captiv... more In an experiment performed to characterize the reproductive behavior of the discus fish in captivity, couple formation with two females was observed. The observations were carried out in captivity, based on ad libitum methodology. Adult individuals were allowed to naturally form couples. The couple formation was considered when individuals performed the substrate cleaning behavior. Fifteen couples were selected. The eggs of three couples did not initiate embryonic development and became infeasible within three days after spawning. We found that these spawnings belonged to all-female couples. The sex of the individuals in same-sex couples was confirmed through subsequent couple formation and spawning of fertile eggs with known males. Eggs were deposited by one or both females in the same-sex couples. Double spawnings were larger and differentially colored. The motivations that lead individuals of the same sex to form couples in this species are still unknown.

Brazilian Journal of Veterinary Research and Animal Science, 2007

O objetivo deste trabalho foi verificar a viabilidade da utilização do espermatócrito para estima... more O objetivo deste trabalho foi verificar a viabilidade da utilização do espermatócrito para estimar a concentração espermática do sêmen de piabanha. Os exemplares (n=29) de piabanha Brycon insignis foram hipofisados, sendo posteriormente realizada a coleta de sêmen. O espermatócrito foi determinado utilizando-se micro-centrífuga de tubos capilares. A concentração espermática foi verificada por contagem em câmara de Neubauer, após diluição. A concentração espermática verificada (média±desvio padrão) foi de 24,38 ± 3,84 x 10(9) espermatozóides / mL, e o espermatócrito foi de 16,14±5,20%. A equação de regressão: v = 14,01.10(9) + 0,6428.10(9).X foi significativa (P<0,01) e apresentou R² ajustado = 0,75. Deste modo, é possível estimar a concentração através da determinação do espermatócrito.

Acta Amazonica, 2016

The blue discus (Symphysodon aequifasciatus) is often sold for ornamental purposes. It is a neotr... more The blue discus (Symphysodon aequifasciatus) is often sold for ornamental purposes. It is a neotropical cichlid from South America, which is native to the rivers of the Amazon basin of Brazil, Peru and Colombia. The purpose of this study was to characterize the reproductive behavior of S. aequifasciatus and identify features that can later be used by breeders to facilitate the handling and reproduction of this species in captivity. The experiment was divided into two stages: the first dealt with partner selection and couple formation to observe the behaviors of territoriality, pursuing, fleeing, biting, stay, protecting and cleaning of the substrate. The second stage documented mating behavior, nesting and parental care, to observe vibration, spawning, permanence with the offspring, aeration of eggs, cleaning of spawning, color change and shift-taking in parental care. The results of the study allowed identifying disputes for and establishment of territory, as well as the selection ...

Zootecnia Tropical, Oct 1, 2007

Realizing the need for more clarification on the status of research on Fish Nutrition, this work ... more Realizing the need for more clarification on the status of research on Fish Nutrition, this work aimed to do a bibliometric study, using the Scopus database, using the entries Fish Nutrition and Enzyme Activity, both in Brazil and worldwide. The results were presented stratified, showing the tendencies of publication in the specific knowledge area. The research in the Scopus database was performed on January 2012, taking into account the historical series from 1999 to 2010. The data obtained from the research were: number of publications per year or historic series, publication by author, by area, by journal, by institution, by country and the language of the publication. The analysis of the concentration was performed by the comparison of the number of publication of the 10 main contributors (countries, knowledge area, authors, institutions and journal) in relation to the total of publications from Scopus database. For a temporal analysis, were used exponential regression equations...

Zygote, 2015

SummaryThe present study aimed to provide data on the time required for Melanotaenia boesemani to... more SummaryThe present study aimed to provide data on the time required for Melanotaenia boesemani to complete embryonic development, and to investigate the influence that incubation at different temperatures caused in this species. The effects of temperature on the time and hatching rate are presented, as well as information related to embryonic development stages. After fertilization, the eggs were kept in incubators at 23, 26, 29 or 32°C and observed at predetermined times until the moment of hatching. Stages of development were identified and classified according to morphological and physiological characteristics. Oil droplets were visualized inside the eggs as well as filament adhesion present at the chorion. Embryonic development was similar to that observed in other species of the genus Melanotaenia with hatching and faster development in higher temperatures.

Revista Brasileira de Zootecnia, 2004

Foram realizados dois experimentos com o objetivo de comparar técnicas de digestibilidade de nutr... more Foram realizados dois experimentos com o objetivo de comparar técnicas de digestibilidade de nutrientes de alimentos para peixes, com o uso dos indicadores externos (óxido crômico e carbonato de bário) e internos (cinza insolúvel em ácido, cinza insolúvel em detergente ácido, fibra bruta e fibra detergente ácido) e com a técnica de determinação direta. Tambaquis com 100 g receberam, no primeiro experimento, fubá de milho e, no segundo, farelo de soja. O óxido crômico e o carbonato de bário são indicadores externos efetivos para estimar os coeficientes de digestibilidade dos alimentos para tambaquis. A fibra bruta e a fibra detergente ácido apresentaram baixa recuperação e não estimaram de forma consistente os coeficientes de digestibilidade dos alimentos para tambaquis, subestimando-os. A cinza insolúvel em ácido e a cinza insolúvel em detergente ácido apresentaram alta porcentagem de recuperação e estimaram de forma consistente os coeficientes de digestibilidade dos alimentos para ...

Revista Brasileira de Ciência Veterinária, 1997

Ciência Animal Brasileira, 2011

Revista Ciência Agronômica, 2015

Ciência Animal Brasileira, 2010

Pesquisa Veterinária Brasileira, 2014

Peixes cultivados mostram-se altamente sensíveis a dietas deficientes em ácido ascórbico com sina... more Peixes cultivados mostram-se altamente sensíveis a dietas deficientes em ácido ascórbico com sinais clínicos que afetam o desempenho e a comercialização por provocar deformidades. Com objetivo de conhecer os níveis mínimos para a melanotênia-maçã, foram testadas seis rações isoaminoacídicas e isocalóricas com níveis variados de vitamina C ativa. Ao final dos 42 dias experimentais, 36 peixes foram analisados histologicamente quanto à porcentagem de tecido conjuntivo e fibras musculares a fim de determinar a influência da porcentagem de Vitamina C nesses índices. Apesar de as médias serem estatisticamente iguais do ponto de vista quantitativo, qualitativamente os níveis mais altos de vitamina C possibilitaram melhor estrutura tecidual. A desestruturação do tecido muscular é um indicativo da deficiência alimentar com ácido ascórbico.

Ciência Animal Brasileira, 2011

Neotropical Ichthyology, 2012

In the present study we analysed the proximate-composition and caloric values of the preferred pr... more In the present study we analysed the proximate-composition and caloric values of the preferred prey consumed by ribbonfish, Trichiurus lepturus L. 1758 (adult females), that are distributed in the inner continental shelf from northern Rio de Janeiro State, southeastern Brazil (~22ºS), assessing the potential of nutritional and energetic approach as a tool to understand the feeding selective pattern of this marine top carnivore. The preferred prey of this predator composed of fish co-specifics, Pellona harroweri, Chirocentrodon bleekerianus, Lycengraulis grossidens, Peprilus paru, squid Doryteuthis plei, and shrimp Xiphopenaeus kroyeri were collected from 2007 to 2010 for proximate-composition (water, protein, lipid, ash, and carbohydrate) and caloric value analyses. The correspondence analysis showed that protein is the main component in the prey species (61.32% of variance explained), standing out from the other nutrients. Lipid has the highest percentage related to L. grossidens, ...

Zygote, 2014

SummaryThe aim of this study was to describe the embryonic and larval development of discus fish ... more SummaryThe aim of this study was to describe the embryonic and larval development of discus fish (Symphysodon aequifasciatus), and to determine the time required, hours post fertilization (hpf), for the emergence of various structures. To describe embryonic and larval stages, observations were made at regular periods under an optical microscope and images were taken with a digital camera attached to a microscope. The average temperature reached in the experimental tank was 27.9°C. Important facts in embryonic and larval development are described, such as the closure of the blastopore, which occurred at 31.5 hpf; a period of eruption, which occurred at 58.5 hpf; and a mouth opening, which occurred at 90.5 hpf; and larvae that exhibited oriented swimming and eating exogenous food at 136.5 hpf.