Laura Nakaghi - Academia.edu (original) (raw)
Papers by Laura Nakaghi
Journal of Applied Ichthyology
Journal of Applied Ichthyology
Zygote
Summary This study investigated and analysed survival, growth and macro- and microscopic damage d... more Summary This study investigated and analysed survival, growth and macro- and microscopic damage during the development of zebrafish embryos up to the adult stage after undergoing cooling. The embryos at 50% epiboly stage were selected, submerged in cryoprotectant solution of methanol and sucrose, cooled gradually to 0 ± 2°C temperature, and divided into two groups with different storage times (6 and 18 h). Subsequently, the embryos were reheated, rehydrated and incubated normally. The experiment lasted 5 months and, from hatching onward, the larvae were examined, collected and processed at pre-established time intervals. The hatching rate was significantly higher for the larvae stored for 18 h compared with the 6-h group. However, embryos from this group gave rise to a larger number of malformations, and these were much more severe compared with those in the 6 h group, which led to a higher mortality in the long term. Regarding larval length, the animals of the 6 h group had higher ...
Zygote
SummaryIn this study we analyzed whether the in vivo storage of oocytes (time after ovulation unt... more SummaryIn this study we analyzed whether the in vivo storage of oocytes (time after ovulation until fertilization) affects the survival and the ploidy status of the yellowtail tetra Astyanax altiparanae. Fish were induced to spawn and, after ovulation, a small aliquot was stripped and immediately fertilized (positive control group). Subsequently, aliquots (~150 oocytes) were stripped and fertilized at various time points of 60, 120, 180 or 240 min. Developmental stages, abnormalities, survival and the ploidy status of the hatched larvae were examined. As expected, in the control group, 100% of the larvae were diploid. Conversely, triploid individuals were observed just at the 60 min treatment time point (0.6%). In vivo storage of oocytes also influenced the survival rates (P < 0.05); the 180 and 240 min samples, respectively, presented lower survival rates at gastrula (50.10±6.26% and 40.92±5.32%), and somite (17.80±5.14% and 4.41±2.76%) stages and lower hatching rates (12.01±4.0...
Zygote
Summary Brycon orbignyanus is an important large teleost that is currently on the list of endange... more Summary Brycon orbignyanus is an important large teleost that is currently on the list of endangered species, therefore studies on its reproductive biology and embryology are fundamental to help species conservation and recovery. The objective of this research was to characterize the events that occur during extrusion, fertilization and embryonic development of the species. The samples were collected at predetermined times, fixed and processed for light microscopy and scanning electron microscopy. The greenish oocytes were spherical, had translucent chorion and a mean diameter of 1.3±0.11 mm. The eggs had well defined animal and vegetative poles approximately 18 min post-fertilization. Stages from 2 to 128 blastomeres occurred between 20 min and 3 h post-fertilization (hPF), when the morula was characterized. The blastula stage was observed between 2 and 3 hPF, and the gastrula between 3 and 7 hPF, when the embryonic shield emerged and the cellular migration with the consequent form...
Zygote (Cambridge, England), 2018
In fish, many factors can affect reproduction during in vitro fertilization, therefore determinat... more In fish, many factors can affect reproduction during in vitro fertilization, therefore determination of the factors that affect affecting gamete quality is needed. However, few studies have focused on gamete quality and the ploidy status. This study was conducted to elucidate whether oocyte storage can affect ploidy status, survival, and embryo viability in the characid species Astyanax altiparanae. Oocytes were stored in Dulbecco's phosphate-buffered saline (PBS) at 26°C, then aliquots were fertilized immediately after extrusion (control) and also after 60, 120, 180, and 240 min of storage. Fertilization and hatching rates were measured, and the developmental stages were analyzed at each stage before describing the main abnormalities. Ploidy status was analyzed by flow cytometry and blood smear. In the control group, 100% of the samples were diploid. After treatment for 60 min, 95.56 ± 4.44% samples were diploid and 4.44 ± 4.44% were triploid. After 120 min, 94.44 ± 9.62% of th...
Zygote (Cambridge, England), 2017
In fish with external fertilization, sperm must reach the oocyte through the micropyle to enter t... more In fish with external fertilization, sperm must reach the oocyte through the micropyle to enter the cytoplasm. Fertilization success is then influenced by characteristics of oocytes or sperm. In this study, we evaluated oocyte morphology and sperm motility parameters and their effects on the inseminating dose in a teleost fish Astyanax altiparanae. Interestingly, we found one of the lowest yet described inseminating doses in teleosts (2390 spermatozoa oocyte-1 ml-1). Such a fertilization efficacy may be explained by the long duration of sperm motility (>75 s), the small oocyte diameter (695.119 µm), large micropyle diameter (7.57 µm), and the presence of grooves on the oocyte surface that guides spermatozoon to the fertilization area. Additionally, we have described for the first time a structure that combines grooves on the chorion surface and a ridge in the micropylar area.
Aquaculture
The aim of this study was to evaluate the growth, carcass yield, fatty acid composition, and repr... more The aim of this study was to evaluate the growth, carcass yield, fatty acid composition, and reproductive parameters of diploid and triploid Astyanax altiparanae. Triploidization was induced by heat shock (40°C for 2 min) 2 min after fertilization. Fish were reared for 175 days from fertilization. Triploid females showed lower proportion of saturated and poly-unsaturated fatty acids and higher amount of mono-unsaturated fatty acids than diploids. They were sterile, with immature gonads, and showed higher carcass yield than diploid females, which exhibited higher gonadosomatic indices. Triploid and diploid males showed similar gonad morphology, although diploid males produced greater numbers of spermatozoa. All males exhibited the secondary sex characteristic of spines in the pelvic and anal fins. Fatty acid composition and growth were similar in triploid and diploid males. Triploidy did not ensure sterility in males, but triploid females were sterile and had increased carcass yield, and may be used in aquaculture to increase the production of A. altiparanae. Statement of relevance: To our knowledge, this is the first study addressing the effect of triploid induction on growth parameters of a neotropical species. The important results for carcass yield and sterility in female triploid will improve the production of A. altiparane, as this species is being used as live-bait for sport fishing and direct consumption.
Zygote
Summary Primordial germ cell (PGC) transplant is a promising tool in aquaculture; however, succes... more Summary Primordial germ cell (PGC) transplant is a promising tool in aquaculture; however, successful use of this technique requires in depth knowledge of the early stages of embryo and larval development. The aim of this study was to analyse the effect of different temperatures (22, 26, and 30°C) on the early development of B. amazonicus. The newly fertilized eggs were distributed into tanks with controlled temperature and oxygenation. Samples were collected at pre-established times and analysed under light and fluorescence microscopy. Temperature influenced the speed and duration of each stage of early development, including hatching time. The highest pronuclei fusion rate was observed 8 min post-fertilization (mpf) at 22 and 26°C, and 6 mpf at 30°C. The duration of the 512–1000 blastomeres phase during in the blastocyst stage was 1 h 30 min at 22°C, and 25 min at 26 and 30°C. Hatching occurred at 24 h 30 mpf at 22°C, 16 h post-fertilization (hpf) at 26°C, and 11 h 30 mpf at 30°C....
Zygote (Cambridge, England), Jan 2, 2017
This study aimed to examine the gonadal morphology of diploid and triploid fish through stereolog... more This study aimed to examine the gonadal morphology of diploid and triploid fish through stereological analysis. Triploid individuals were obtained after temperature shock (40°C for 2 min) at 2 min post-fertilization and reared until 175 days post-fertilization (dpf). Intact eggs were used to obtain the diploids. Gonads were collected for histological analysis at 83, 114, 144 and 175 dpf. Diploid females and males presented normal oogenesis and spermatogenesis through all the experimental period. Conversely, stereological analysis revealed that triploid females were sterile and oogonia were the prevalent cell type in the ovaries. Triploid males presented increased amounts of spermatocyte cysts and a large area of lumen when compared with diploids and in addition the amount of spermatozoa was lower than that observed for diploids. However, some triploid males presented spermatogenesis similar to diploids. Therefore, we concluded that triploidization is an interesting alternative to pr...
Zygote, 2017
Summary The Zungaro jahu is an important large catfish of the order Siluriformes that is in dange... more Summary The Zungaro jahu is an important large catfish of the order Siluriformes that is in danger of extinction due to habitat destruction. Studies on its biology are scarce and the majority relates only to nutrition or parasitology. In order to provide greater information on its morphology and aid husbandry and larviculture studies, the aim of this study was to characterize larval development in Z. jahu from hatching to total yolk absorption. Samples were collected at pre-established times, processed, stained, and analyzed under stereomicroscopy, light microscopy, and scanning electron microscopy. Total yolk absorption was observed by 60 hours post-hatching (hph) at 28.75 ± 0.59°C. The newly hatched larvae showed slightly pigmented body, the outline of the digestive tract, evident eyes, and the first swimming movements. Mouth opening took place at 12 hph and the connection between the oral cavity and the rudimentary intestine was observed at 24 hph. Were analyzed the main larval o...
Zygote, 2016
Summary The aim of this study was to characterize the embryonic development of Zungaro jahu, a fr... more Summary The aim of this study was to characterize the embryonic development of Zungaro jahu, a fresh water teleostei commonly known as ‘jaú’. Samples were collected at pre-determined times from oocyte release to larval hatching and analysed under light microscopy, transmission electron microscopy and scanning electron microscopy. At the first collection times, the oocytes and eggs were spherical and yellowish, with an evident micropyle. Embryo development took place at 29.4 ± 1.5°C and was divided into seven stages: zygote, cleavage, morula, blastula, gastrula, organogenesis, and hatching. The differentiation of the animal and vegetative poles occured during the zygote stage, at 10 min post-fertilization (mpf), leading to the development of the egg cell at 15 mpf. From 20 to 75 mpf, successive cleavages resulted in the formation of 2, 4, 8, 16, 32 and 64 blastomeres. The morula stage was observed between 90 and 105 mpf, and the blastula and gastrula stage at 120 and 180 mpf; respect...
Brazilian Journal of Veterinary Research and Animal Science, 2010
A tilápia-do-Nilo, Oreochromis niloticus, é a espécie de água doce mais utilizada nos cultivos co... more A tilápia-do-Nilo, Oreochromis niloticus, é a espécie de água doce mais utilizada nos cultivos comerciais, principalmente por sua rusticidade, rápido crescimento, carne de ótima qualidade e boa aceitação pelo mercado de lazer (pesque-pague) e alimentício (frigoríficos) pelas qualidades nutritivas e organolépticas do seu filé 1,2,3. Diferentes granulometrias de rações sobre o ganho de peso, crescimento, sobrevivência e reversão sexual para tilápias-do-Nilo (Oreochromis niloticus) Different diameters of diets about weight gain, growing, survival and sex reversal to Nile tilapia (Oreochromis niloticus
Pesquisa Veterinária Brasileira, 2016
Resumo: Para verificação da ocorrência de alterações morfológicas no fígado, foram coletados dez ... more Resumo: Para verificação da ocorrência de alterações morfológicas no fígado, foram coletados dez animais de cada dieta, no 30º dia (1º período experimental) e no 60º dia (2º período experimental), sendo esse, o último dia do período experimental e início do clímax da metamorfose. Os girinos foram distribuídos em delineamento experimental inteiramente casualizado (DIC) com três tratamentos: dieta experimental com 32,68% de proteína bruta e duas dietas comerciais com 37,92% e 57,53% de proteína bruta. Os órgãos coletados foram fixados em solução de Bouin e depois submetidos às práticas da rotina histotecnológica e coradas com hematoxilina - Eosina (HE). Na avaliação microscópica do fígado foram encontradas diversas alterações morfológicas como: Desorganização e vacuolização de hepatócitos, infiltrado inflamatório mononuclear periportal, multifocal e difuso, infiltrado inflamatório eosinofílico, congestão, hemorragia, hemólise e necrose. As alterações hepáticas encontradas neste estudo...
Aquaculture Research, 2016
Journal of aquatic animal health, Sep 1, 2016
In this study, sex and age influenced the hematological profiles of Jundiá (Silver Catfish) Rhamd... more In this study, sex and age influenced the hematological profiles of Jundiá (Silver Catfish) Rhamdia quelen. Females showed lower levels of hemoglobin, young fish increased lymphocyte counts, and older fish increased hematocrit values. These results indicate that, depending on age and sex, the fish have disparate hematological profiles. For this reason, it is important to consider the sex and age of an R. quelen when examining the impact of environmental and management factors on this species in terms of their hematological profiles. Received May 24, 2015; accepted March 24, 2016.
Journal of Applied Ichthyology
Journal of Applied Ichthyology
Zygote
Summary This study investigated and analysed survival, growth and macro- and microscopic damage d... more Summary This study investigated and analysed survival, growth and macro- and microscopic damage during the development of zebrafish embryos up to the adult stage after undergoing cooling. The embryos at 50% epiboly stage were selected, submerged in cryoprotectant solution of methanol and sucrose, cooled gradually to 0 ± 2°C temperature, and divided into two groups with different storage times (6 and 18 h). Subsequently, the embryos were reheated, rehydrated and incubated normally. The experiment lasted 5 months and, from hatching onward, the larvae were examined, collected and processed at pre-established time intervals. The hatching rate was significantly higher for the larvae stored for 18 h compared with the 6-h group. However, embryos from this group gave rise to a larger number of malformations, and these were much more severe compared with those in the 6 h group, which led to a higher mortality in the long term. Regarding larval length, the animals of the 6 h group had higher ...
Zygote
SummaryIn this study we analyzed whether the in vivo storage of oocytes (time after ovulation unt... more SummaryIn this study we analyzed whether the in vivo storage of oocytes (time after ovulation until fertilization) affects the survival and the ploidy status of the yellowtail tetra Astyanax altiparanae. Fish were induced to spawn and, after ovulation, a small aliquot was stripped and immediately fertilized (positive control group). Subsequently, aliquots (~150 oocytes) were stripped and fertilized at various time points of 60, 120, 180 or 240 min. Developmental stages, abnormalities, survival and the ploidy status of the hatched larvae were examined. As expected, in the control group, 100% of the larvae were diploid. Conversely, triploid individuals were observed just at the 60 min treatment time point (0.6%). In vivo storage of oocytes also influenced the survival rates (P < 0.05); the 180 and 240 min samples, respectively, presented lower survival rates at gastrula (50.10±6.26% and 40.92±5.32%), and somite (17.80±5.14% and 4.41±2.76%) stages and lower hatching rates (12.01±4.0...
Zygote
Summary Brycon orbignyanus is an important large teleost that is currently on the list of endange... more Summary Brycon orbignyanus is an important large teleost that is currently on the list of endangered species, therefore studies on its reproductive biology and embryology are fundamental to help species conservation and recovery. The objective of this research was to characterize the events that occur during extrusion, fertilization and embryonic development of the species. The samples were collected at predetermined times, fixed and processed for light microscopy and scanning electron microscopy. The greenish oocytes were spherical, had translucent chorion and a mean diameter of 1.3±0.11 mm. The eggs had well defined animal and vegetative poles approximately 18 min post-fertilization. Stages from 2 to 128 blastomeres occurred between 20 min and 3 h post-fertilization (hPF), when the morula was characterized. The blastula stage was observed between 2 and 3 hPF, and the gastrula between 3 and 7 hPF, when the embryonic shield emerged and the cellular migration with the consequent form...
Zygote (Cambridge, England), 2018
In fish, many factors can affect reproduction during in vitro fertilization, therefore determinat... more In fish, many factors can affect reproduction during in vitro fertilization, therefore determination of the factors that affect affecting gamete quality is needed. However, few studies have focused on gamete quality and the ploidy status. This study was conducted to elucidate whether oocyte storage can affect ploidy status, survival, and embryo viability in the characid species Astyanax altiparanae. Oocytes were stored in Dulbecco's phosphate-buffered saline (PBS) at 26°C, then aliquots were fertilized immediately after extrusion (control) and also after 60, 120, 180, and 240 min of storage. Fertilization and hatching rates were measured, and the developmental stages were analyzed at each stage before describing the main abnormalities. Ploidy status was analyzed by flow cytometry and blood smear. In the control group, 100% of the samples were diploid. After treatment for 60 min, 95.56 ± 4.44% samples were diploid and 4.44 ± 4.44% were triploid. After 120 min, 94.44 ± 9.62% of th...
Zygote (Cambridge, England), 2017
In fish with external fertilization, sperm must reach the oocyte through the micropyle to enter t... more In fish with external fertilization, sperm must reach the oocyte through the micropyle to enter the cytoplasm. Fertilization success is then influenced by characteristics of oocytes or sperm. In this study, we evaluated oocyte morphology and sperm motility parameters and their effects on the inseminating dose in a teleost fish Astyanax altiparanae. Interestingly, we found one of the lowest yet described inseminating doses in teleosts (2390 spermatozoa oocyte-1 ml-1). Such a fertilization efficacy may be explained by the long duration of sperm motility (>75 s), the small oocyte diameter (695.119 µm), large micropyle diameter (7.57 µm), and the presence of grooves on the oocyte surface that guides spermatozoon to the fertilization area. Additionally, we have described for the first time a structure that combines grooves on the chorion surface and a ridge in the micropylar area.
Aquaculture
The aim of this study was to evaluate the growth, carcass yield, fatty acid composition, and repr... more The aim of this study was to evaluate the growth, carcass yield, fatty acid composition, and reproductive parameters of diploid and triploid Astyanax altiparanae. Triploidization was induced by heat shock (40°C for 2 min) 2 min after fertilization. Fish were reared for 175 days from fertilization. Triploid females showed lower proportion of saturated and poly-unsaturated fatty acids and higher amount of mono-unsaturated fatty acids than diploids. They were sterile, with immature gonads, and showed higher carcass yield than diploid females, which exhibited higher gonadosomatic indices. Triploid and diploid males showed similar gonad morphology, although diploid males produced greater numbers of spermatozoa. All males exhibited the secondary sex characteristic of spines in the pelvic and anal fins. Fatty acid composition and growth were similar in triploid and diploid males. Triploidy did not ensure sterility in males, but triploid females were sterile and had increased carcass yield, and may be used in aquaculture to increase the production of A. altiparanae. Statement of relevance: To our knowledge, this is the first study addressing the effect of triploid induction on growth parameters of a neotropical species. The important results for carcass yield and sterility in female triploid will improve the production of A. altiparane, as this species is being used as live-bait for sport fishing and direct consumption.
Zygote
Summary Primordial germ cell (PGC) transplant is a promising tool in aquaculture; however, succes... more Summary Primordial germ cell (PGC) transplant is a promising tool in aquaculture; however, successful use of this technique requires in depth knowledge of the early stages of embryo and larval development. The aim of this study was to analyse the effect of different temperatures (22, 26, and 30°C) on the early development of B. amazonicus. The newly fertilized eggs were distributed into tanks with controlled temperature and oxygenation. Samples were collected at pre-established times and analysed under light and fluorescence microscopy. Temperature influenced the speed and duration of each stage of early development, including hatching time. The highest pronuclei fusion rate was observed 8 min post-fertilization (mpf) at 22 and 26°C, and 6 mpf at 30°C. The duration of the 512–1000 blastomeres phase during in the blastocyst stage was 1 h 30 min at 22°C, and 25 min at 26 and 30°C. Hatching occurred at 24 h 30 mpf at 22°C, 16 h post-fertilization (hpf) at 26°C, and 11 h 30 mpf at 30°C....
Zygote (Cambridge, England), Jan 2, 2017
This study aimed to examine the gonadal morphology of diploid and triploid fish through stereolog... more This study aimed to examine the gonadal morphology of diploid and triploid fish through stereological analysis. Triploid individuals were obtained after temperature shock (40°C for 2 min) at 2 min post-fertilization and reared until 175 days post-fertilization (dpf). Intact eggs were used to obtain the diploids. Gonads were collected for histological analysis at 83, 114, 144 and 175 dpf. Diploid females and males presented normal oogenesis and spermatogenesis through all the experimental period. Conversely, stereological analysis revealed that triploid females were sterile and oogonia were the prevalent cell type in the ovaries. Triploid males presented increased amounts of spermatocyte cysts and a large area of lumen when compared with diploids and in addition the amount of spermatozoa was lower than that observed for diploids. However, some triploid males presented spermatogenesis similar to diploids. Therefore, we concluded that triploidization is an interesting alternative to pr...
Zygote, 2017
Summary The Zungaro jahu is an important large catfish of the order Siluriformes that is in dange... more Summary The Zungaro jahu is an important large catfish of the order Siluriformes that is in danger of extinction due to habitat destruction. Studies on its biology are scarce and the majority relates only to nutrition or parasitology. In order to provide greater information on its morphology and aid husbandry and larviculture studies, the aim of this study was to characterize larval development in Z. jahu from hatching to total yolk absorption. Samples were collected at pre-established times, processed, stained, and analyzed under stereomicroscopy, light microscopy, and scanning electron microscopy. Total yolk absorption was observed by 60 hours post-hatching (hph) at 28.75 ± 0.59°C. The newly hatched larvae showed slightly pigmented body, the outline of the digestive tract, evident eyes, and the first swimming movements. Mouth opening took place at 12 hph and the connection between the oral cavity and the rudimentary intestine was observed at 24 hph. Were analyzed the main larval o...
Zygote, 2016
Summary The aim of this study was to characterize the embryonic development of Zungaro jahu, a fr... more Summary The aim of this study was to characterize the embryonic development of Zungaro jahu, a fresh water teleostei commonly known as ‘jaú’. Samples were collected at pre-determined times from oocyte release to larval hatching and analysed under light microscopy, transmission electron microscopy and scanning electron microscopy. At the first collection times, the oocytes and eggs were spherical and yellowish, with an evident micropyle. Embryo development took place at 29.4 ± 1.5°C and was divided into seven stages: zygote, cleavage, morula, blastula, gastrula, organogenesis, and hatching. The differentiation of the animal and vegetative poles occured during the zygote stage, at 10 min post-fertilization (mpf), leading to the development of the egg cell at 15 mpf. From 20 to 75 mpf, successive cleavages resulted in the formation of 2, 4, 8, 16, 32 and 64 blastomeres. The morula stage was observed between 90 and 105 mpf, and the blastula and gastrula stage at 120 and 180 mpf; respect...
Brazilian Journal of Veterinary Research and Animal Science, 2010
A tilápia-do-Nilo, Oreochromis niloticus, é a espécie de água doce mais utilizada nos cultivos co... more A tilápia-do-Nilo, Oreochromis niloticus, é a espécie de água doce mais utilizada nos cultivos comerciais, principalmente por sua rusticidade, rápido crescimento, carne de ótima qualidade e boa aceitação pelo mercado de lazer (pesque-pague) e alimentício (frigoríficos) pelas qualidades nutritivas e organolépticas do seu filé 1,2,3. Diferentes granulometrias de rações sobre o ganho de peso, crescimento, sobrevivência e reversão sexual para tilápias-do-Nilo (Oreochromis niloticus) Different diameters of diets about weight gain, growing, survival and sex reversal to Nile tilapia (Oreochromis niloticus
Pesquisa Veterinária Brasileira, 2016
Resumo: Para verificação da ocorrência de alterações morfológicas no fígado, foram coletados dez ... more Resumo: Para verificação da ocorrência de alterações morfológicas no fígado, foram coletados dez animais de cada dieta, no 30º dia (1º período experimental) e no 60º dia (2º período experimental), sendo esse, o último dia do período experimental e início do clímax da metamorfose. Os girinos foram distribuídos em delineamento experimental inteiramente casualizado (DIC) com três tratamentos: dieta experimental com 32,68% de proteína bruta e duas dietas comerciais com 37,92% e 57,53% de proteína bruta. Os órgãos coletados foram fixados em solução de Bouin e depois submetidos às práticas da rotina histotecnológica e coradas com hematoxilina - Eosina (HE). Na avaliação microscópica do fígado foram encontradas diversas alterações morfológicas como: Desorganização e vacuolização de hepatócitos, infiltrado inflamatório mononuclear periportal, multifocal e difuso, infiltrado inflamatório eosinofílico, congestão, hemorragia, hemólise e necrose. As alterações hepáticas encontradas neste estudo...
Aquaculture Research, 2016
Journal of aquatic animal health, Sep 1, 2016
In this study, sex and age influenced the hematological profiles of Jundiá (Silver Catfish) Rhamd... more In this study, sex and age influenced the hematological profiles of Jundiá (Silver Catfish) Rhamdia quelen. Females showed lower levels of hemoglobin, young fish increased lymphocyte counts, and older fish increased hematocrit values. These results indicate that, depending on age and sex, the fish have disparate hematological profiles. For this reason, it is important to consider the sex and age of an R. quelen when examining the impact of environmental and management factors on this species in terms of their hematological profiles. Received May 24, 2015; accepted March 24, 2016.