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【Objective】The transparent traits in Pterophyllum scalare has high economic and scientific value. This article aims to explore the differential expression genes (DEG) between transparent gill cover (TGC) and opaque gill cover (OGC) tissues of P. scalare, and explore the relevant signaling pathways affecting the transparent gill cover traits of P. scalare, so as to provide a theoretical basis for the subsequent screening of key genes regulating the transparent gill cover trait of P. scalare and related mechanism studies.【Method】The gill cover tissue of P. scalare (strain: red-topped tri-color) was selected as the research material, and 6 samples were selected from each group of OGC and TGC. Transcriptomic sequencing was carried out based on the Illumina Novaseq 6000 sequencing platform with using Fastp to perform quality control on raw sequencing data. The transcript and the corresponding single gene (Unigene) were obtained by de novo assembling of quality control data by Trinity software, and the initial assembly sequence was deredundancy analysis and result evaluation by CD-HIT software and BUSCO software, respectively. After redundancy, unigene were functionally annotated based on sequence homology. RSEM software was used to calculate the expression of unigene in each sample. DEGs between OGC and TGC were calculated using DESeq2 software. GO and KEGG pathway enrichment analysis was performed on DEGs using Goatools software and KOBAS software, respectively.【Result】(1) After quality control of sequencing data, the average error rate of each sample sequencing base was less than 0.1%, Q20 was higher than 97.78%, and Q30 was higher than 93.58%, and the sequencing quality was reliable. After de novo assembling, 200 303 transcripts were obtained, corresponding to 123 178 unigenes. After deredundancy analysis, a total of 147 932 transcripts are obtained, corresponding to 108 070 unigenes, with an average length of 991.85 bp and N50 is 2 430 bp. (2) A total of 40 180 unigenes were annotated in the NR, KEGG, eggNOG, GO, Pfam, and Swiss-Prot databases, accounting for 37.98% of the total, of which 10 747 genes were annotated simultaneously in 6 databases, accounting for 26.75% of the total. (3) TGC relative to OGC has a total of 432 DEGs, of which TGC significantly up-regulated 267 genes and down-regulated 165 genes relative to OGC. (4) GO enrichment results showed that 432 DEGs were mainly enriched in 5 biological pathways: IMP biosynthesis, IMP metabolism, "de novo" IMP biosynthesis, amino acid binding, and modified amino acid binding. (5) KEGG enrichment results showed that 432 DEGs were mainly enriched in 7 biological pathways: neuroactive ligand-receptor interaction, tyrosine metabolism, purine metabolism, a carbon pool of folate, phenylalanine metabolism, nucleotide metabolism, ubiquinone and other terpene-quinone biosynthesis.【Conclusion】432 genes related to the transparent gill cover trait of P. scalare were obtained by transcriptomic sequencing, which were mainly involved in 12 signaling pathways. The results will provide reference for the mining and functional study of genes related to transparent gill cover trait in P. scalare.

【Objective】The transparent traits in Pterophyllum scalare has high economic and scientific value. This article aims to explore the differential expression genes (DEG) between transparent gill cover (TGC) and opaque gill cover (OGC) tissues of P. scalare, and explore the relevant signaling pathways affecting the transparent gill cover traits of P. scalare, so as to provide a theoretical basis for the subsequent screening of key genes regulating the transparent gill cover trait of P. scalare and related mechanism studies.【Method】The gill cover tissue of P. scalare (strain: red-topped tri-color) was selected as the research material, and 6 samples were selected from each group of OGC and TGC. Transcriptomic sequencing was carried out based on the Illumina Novaseq 6000 sequencing platform with using Fastp to perform quality control on raw sequencing data. The transcript and the corresponding single gene (Unigene) were obtained by de novo assembling of quality control data by Trinity software, and the initial assembly sequence was deredundancy analysis and result evaluation by CD-HIT software and BUSCO software, respectively. After redundancy, unigene were functionally annotated based on sequence homology. RSEM software was used to calculate the expression of unigene in each sample. DEGs between OGC and TGC were calculated using DESeq2 software. GO and KEGG pathway enrichment analysis was performed on DEGs using Goatools software and KOBAS software, respectively. 【Result】(1) After quality control of sequencing data, the average error rate of each sample sequencing base was less than 0.1%, Q20 was higher than 97.78%, and Q30 was higher than 93.58%, and the sequencing quality was reliable. After de novo assembling, 200 303 transcripts were obtained, corresponding to 123 178 unigenes. After deredundancy analysis, a total of 147 932 transcripts are obtained, corresponding to 108 070 unigenes, with an average length of 991.85 bp and N50 is 2 430 bp. (2) A total of 40 180 unigenes were annotated in the NR, KEGG, eggNOG, GO, Pfam, and Swiss-Prot databases, accounting for 37.98% of the total, of which 10 747 genes were annotated simultaneously in 6 databases, accounting for 26.75% of the total. (3) TGC relative to OGC has a total of 432 DEGs, of which TGC significantly up-regulated 267 genes and down-regulated 165 genes relative to OGC. (4) GO enrichment results showed that 432 DEGs were mainly enriched in 5 biological pathways: IMP biosynthesis, IMP metabolism, “de novo” IMP biosynthesis, amino acid binding, and modified amino acid binding. (5) KEGG enrichment results showed that 432 DEGs were mainly enriched in 7 biological pathways: neuroactive ligand-receptor interaction, tyrosine metabolism, purine metabolism, a carbon pool of folate, phenylalanine metabolism, nucleotide metabolism, ubiquinone and other terpene-quinone biosynthesis. 【Conclusion】432 genes related to the transparent gill cover trait of P. scalare were obtained by transcriptomic sequencing, which were mainly involved in 12 signaling pathways. The results will provide reference for the mining and functional study of genes related to transparent gill cover trait in P. scalare. [ABSTRACT FROM AUTHOR]

The freshwater angelfish (Pterophyllum scalare) is a quite popular freshwater ornamental fish in Indonesia due to its distinguished body shape and pattern. However, its growth tends to be slow due to low nutrients in its main diet, namely Daphnia magna. The most feasible solution is to enrich D. magna to increase its nutritional content with Viterna (livestock vitamins). The purpose of this study was to determine the effectiveness of D. magna enriched with Viterna to increase the growth of freshwater angelfish. This study used a Completely Randomized Design to compare three enrichment dosages (10, 20, and 30 ml/L) with a non-enriched control in three replications. This study showed that 3 hours-enrichment can result in an increase in fat (0.6%) and protein (1.25%) profiles in D. magna. Absolute Weight Growth (AWG), Absolute Length Growth (ALG), and Specific Growth Rates (SGR) showed significant differences (P=0.05) between all treatments. The best result was obtained at a Viterna dosage of 30 ml/L which resulted in an Absolute Weight Growth value of 207.14 mg, an Absolute Length Growth of 14.19 mm, and an SGR of 2.58%/day. Survival rates during the larvae culture were not statistically different (P=0.05) among the treatments. Enrichment of D. magna with Viterna has been proven to optimize its potential as live food for fish larvae cultivation. [ABSTRACT FROM AUTHOR]

This study aimed to identify the cause of sustained mortality in freshwater angelfish (Pterophyllum scalare Schultze, 1823) kept at an ornamental fish production facility in Türkiye. Parasitological, bacteriological and histopathological examination were performed on moribund hybrid angelfish individuals. The moribund fish had haemorrhaged eyes, darkened skin, scale loss, ascites and false faeces. A pale liver, splenomegaly and a thinning of the intestinal wall were observed internally. The parasitological examination revealed flagellated protozoan endoparasite Spironucleus sp. in the intestine. A number of histopathological changes were observed including lipid degeneration in the liver, hemosiderin deposits as well as granulomas in the spleen, a large number of mast cells in the lamina propria of the intestine and enteritis. Numerous Spironucleus parasites were seen in the intestinal wall. According to physiological and biochemical tests, the bacterial isolates obtained from the visceral organs of some fish were identified as Citrobacter freundii. After oral metronidazole treatment, with a dose of 50 mg/kg fish daily for 5 days, a decrease in fish mortality and resumed feeding were noted. A chronic spironucleosis, which systemically affects fish by penetrating the intestinal mucosa, was identified as the cause of this sustained mortality in freshwater angelfish. [ABSTRACT FROM AUTHOR]

Nghiên cứu được thực hiện bằng cách ngâm đàn cá thần tiên con giai đoạn 7 ngày tuổi sau khi nở trong dung dịch có chứa Spironolacton (SP) với các liều lượng khác nhau. Cá con được ngâm riêng trong các túi polyethylen với thể tích 100 mL nước cho 100 cá con có pha sẵn SP với hàm lượng 0 mg/L, 5 mg/L, 10 mg/L và 15 mg/L, túi được bơm oxy tươi và giữ trong vòng 2 giờ, sau đó cá con được cho vào các bể và nuôi riêng. Sau khi cá đạt 90 ngày tuổi, xác định giới tính cá dựa vào hình thái bên ngoài và mổ cá, quan sát cơ quan sinh dục. Hiệu suất đực hóa cao nhất ở liều 15mg/L với 86,59 ± 2,1%, thấp nhất ở liều 5 mg/L với 74,12 ± 1,9%, sự khác biệt này có ý nghĩa về mặt thống kê (p

The freshwater angelfish (Pterophyllum scalare Schultze, 1823) is a common aquarium species. Similar to many other cichlids, angelfish provide parental care for their embryos and larvae. In contrast to zebrafish and medaka, it is difficult to raise angelfish eggs in the lab. Therefore, obtaining angelfish embryos for transgenic purposes will also be challenging. Our aim in this study was to employ microinjection techniques to develop transgenic angelfish expressing red fluorescent protein (RFP). Using the zebrafish myosin light chain 2 (mylz2) promoter, the expression patterns of the RFP founder transgenic angelfish were analyzed. An open loop of plasmid pDsred2-1 was cloned with the 1999-bp Mylz2 promoter fragment at the SacI and AgeI sites to generate the pMylz2-RFP transgenic construct. After angelfish laid their eggs on the substrate, the embryos were carefully collected with a plastic pipette in preparation for the microinjection procedure. A single-cell-stage angelfish embryo was microinjected with pMylz2-RFP. Sixteen of 524 pMylz2-RFP microinjected embryos survived to five days post fertilization (5 dpf), with twelve displaying red fluorescence. Only two RFP-positive larvae survived to adulthood. In adult angelfish, red LED illumination clearly displayed RFP expression in trunk muscles, indicating successful transmission of the transgene. The pMylz2-RFP transgene, however, was not passed on to offspring, indicating that it was not incorporated into the germline. [ABSTRACT FROM AUTHOR]

The present study examines host pathogen response in developmental stage of Pterophyllum scalare (angelfish) infected with Aeromonas hydrophila. The study conducted had two different experiments in which the fish were subjected to formalin‐killed Aeromonas hydrophila (FKA) and immunostimulant (β‐glucan) by immersion method. The first experiment had three treatment groups viz., immunized, non‐immunized and control groups and the exposure time ranged between 12 and 32 dph (days posthatch) of larval rearing. The immunized group exhibited a higher fold expression of RAG‐1, RAG‐2 and IgM genes compared with non‐immunized group. The results demonstrated that the vaccination of 12 dph developmental stage prior to bacterial challenge of angelfish makes it more immunocompetent against the pathogens. Moreover, another experiment using β‐glucan was conducted to further examine the development of immune responses in angelfish larvae. The study consisted four treatments containing graded levels of β‐glucan dosages such as 100, 200 and 300 mg/L including a control (0 mg/L) for 20 days from 12 to 32 dph. The higher fold change in mRNA expression of RAG‐1, RAG‐2 and IgM genes was observed in β‐glucan (200 mg/L) treated group as compared to non‐treated and control group. The highest survivability was observed in the immunized group and immunostimulant treated group in the survival analysis. Hence, the present study suggested that either immunization with FKA or β‐glucan (200 mg/L) could be used as a strategy to mitigate the mortality rate and combat infection during the early larval rearing of P. scalare. [ABSTRACT FROM AUTHOR]

The present study was planned to determine an optimum live-feeding protocol for angelfish larvae (Pterophyllum scalare). Larvae with an initial weight of 0.10 mg, a length of 4.5 mm, and a depth of 1 mm were reared on three different feeding regimens for 30 days. All experimental larval groups were fed Artemia nauplii from the end of the yolk-sac resorption. The control treatment (Group I) was maintained on Artemia nauplii on days 14-28, and on Artemia nauplii + dry feed on days 29 and 30. Group II was reared with Artemia nauplii enriched with Algamac 3050 on days 14-28 and with dry feed + Artemia nauplii enriched with Algamac 3050 on days 29 and 30, whereas Group III was fed with Artemia nauplii enriched with Red Pepper on days 14-28, and with dry food + Artemia nauplii enriched with Red Pepper on days 29 and 30. The highest weight (37.8±0.51 mg) and length (15.8±0.35 mm) were determined in Group II with significant differences from the control group (p<0.05). However, enrichment treatments were comparable in terms of growth performance (p>0.05). The survival rate of the larvae in the treatments varied between 70-75% without significant differences (p>0.05). Overall, the study results suggest that a feeding protocol for angelfish larvae with the administration of Artemia nauplii during the first two weeks after hatching and then enriched Artemia with Algamac 3050 over the following 14-28 days followed by a gradual weaning onto dry feed. [ABSTRACT FROM AUTHOR]

Quantitative real-time RT-PCR (qRT-PCR) is the most sensitive and advanced method to quantify the expression of target genes of animals including fish. However, the broad variation in the expression patterns of housekeeping genes (HKGs) among tissues and different developmental stages makes it necessary to conduct studies for the selection of the suitable internal control. There is no report available on the reference genes for normalization of gene expression studies in Pterophyllum scalare. In the present study, four reference genes, viz. alpha-actin (α-actin), beta-actin (β-actin), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and elongation factor-alpha 1 (EF1α), were first characterized and then screened for their efficacy as a suitable HKG at different developmental stages and tissue types of P. scalare. The different statistical algorithms such as Delta-cT, NormFinder, and geNorm portray β-actin to be the most suitable gene among the four genes, whereas BestKeeper revealed EF1α as the most stable reference gene during different developmental stages and tissue types. However, comprehensive gene stability method demonstrated β-actin to be the most stable gene for conducting any gene expression studies. In conclusion, β-actin is recommended as the most suitable reference gene among the four selected genes for qPCR data normalization during different developmental stages and tissue types of P. scalare. [ABSTRACT FROM AUTHOR]

We tested the effect of fasting on the development of juvenile freshwater angelfish (Pterophyllum scalare). The juveniles were subjected to different fasting periods (0, 3, 6, 9, 12, and 15 days of fasting). Fish from all treatments were fed for 30 days after the fasting period. No difference (P > 0.05) was observed between treatments for final weight and length. There was a significant difference (P < 0.05) in treatments 12 and 15 days fasting for liver and intestine weight. These results may prove that 12 and 15 days of fasting force juveniles to use energy reserves, and these adaptations may also represent a saving energy strategy. The fish subjected to treatments 6, 9, 12, and 15 days of fasting showed different vacuolization in hepatocytes from the ones subjected to 0 and 3 days of fasting (P < 0.05). These results show that during the lack of feeding, juveniles (P. scalare) mobilizes energy stored in the liver. No difference (P > 0.05) was observed between treatments for survival rate. However, the increase in the number of deaths from the eighth day of fasting may indicate that periods with more than 15 days of fasting could be fatal to this species during this life stage. According to our findings, it can be assumed that juvenile freshwater angelfishes have strategies (e.g. a decrease in liver and intestine weight) to resist 15 days of fasting. [ABSTRACT FROM AUTHOR]

The study was carried out to determine the most convenient time and effect of weaning on the growth and survival rate of Pterophyllum scalare larvae. Accordingly, the transition from live feed to microparticulate feed was experimented at 15th, 20th, 25th, 30th days after hatching and jointly fed with both feeds during 3 days after the last day of groups. After 3-day cooperatively feeding, larvae were fed only with microparticulate feed and the experiment lasted 40 days. Live weight and total length were measured at 15th, 25th, 32nd and 40th days and survival rates were calculated. As a result, a significant difference (P<0.05) was found between W15 and the other three groups for larval survival rates whereas there was no statistical difference between W20, W25 and W30 groups. The survival rates were found as 55.7±16.3%, 93.74±3.5%, 97.13±1.65% and 95.10±1.0%, respectively. There was no statistical difference between the groups in terms of live weight. While there was no significant difference between the groups W15, W20 and W25 in terms of total length, the group W30 was statistically different (P<0.05) from the groups W20 and W25. It was concluded that the best growth in terms of total length was observed in the group W30 (18.49±0.45mm). [ABSTRACT FROM AUTHOR]

Based on previous evidence that environmental enrichment is associated with telencephalic cellular proliferation and that stable visuotopic tectal circuits are essential for discrimination of placement and identity of stationary or moving objects in the visual field, differential plasticity is expected in these areas. Here we tested this hypothesis in the Angelfish (Pterophyllum scalare), a species of ornamental fish with great value in the aquarist trade. We hypothesized that total telencephalic cell number would increase under the influence of an enriched environment whereas the tectal cell number would not change. To test this hypothesis, 12 aquaria of 80 l each were used, with six fish in each. The aquaria had either an enriched environment (EE) including stones, plants, sand and the presence of another fish from the Loricariidae family for interspecific social interaction, or an impoverished environment (IE), in which stimuli were limited to intraspecific interactions in a barren aquarium. After 62 days, six fish from each treatment were euthanized, and their brains were fixed and sectioned for Nissl staining. Then, stereological estimates of the total number of cells were performed. The fish showed no differences in weight gain, feed conversion ratio, condition factor, specific growth rate or survival. Animals kept in the enriched environment had a higher number of total telencephalic cells than animals kept in the impoverished environment (1,038,555 ± 65,357 vs. 758,331 ± 51,587, bilateral t-test, p = 0.008), but a similar number of tectal optical cells (EE 424,097 ± 29,914 vs. IE 471,409 ± 50,850, bilateral t-test, p = 0.445752). We concluded that cell proliferation in response to stimulation by the enriched environment is differentially expressed in the telencephalon and tectal areas of Pterophyllum scalare. [ABSTRACT FROM AUTHOR]

The study was conducted to investigate the effects of dietary green tea extract (GTE) supplementation in diet on growth performance, feed utilization and biometric indexes in freshwater angelfish, Pterophyllum scalare. The fish (mean body weight, 2.61±0.01 g) were fed fish meal diets that included 0% (control), 2.5 and 5% GTE for 8 weeks. The results showed, the addition of green tea extract did not have a positive effect on growth performance and other variables. Addition of green tea extract did not change the amount of viscerosomatic index and hepatosomatic index.

ABSTRACT: Angelfish (Pterophyllum scalare) is a very important species in Brazil's domestic market, however feeding managements differ from fish breeders to aquarists, so the cost of feed and labor become relevant items when cultivating the species. The objective of this research was to assess feeding frequency and feed deprivation based on growth performance, parasite infestation and cost-benefit in farming this species. The experiment was conducted in a completely randomized design in a 3x2 factorial scheme with 3 daily feeding levels, 4 meals, 2 meals and 1 meal; with and without feed deprivation and two repetitions. Feed deprivation consisted of offering feed 5 days a week only. Feeding twice a day without deprivation and four times a day with or without feed deprivation resulted in higher growth performance than feeding once a day. Monogenean and nematode parasitic loads were not influenced by feeding management. The cost-benefit analysis enabled us to observe that the treatment with the best benefit was the one involving two feedings a day with no deprivation. Thus, considering the parameters mentioned above, we concluded that the two daily feedings with no feed deprivation is the most adequate for farming this specie.

Este trabalho registra a ocorrência espontânea de ameloblastoma em P. scalare. O tumor foi obtido a partir de um exemplar de Acará Bandeira, sendo fixado, seccionado, e os fragmentos processados para microscopia de luz e microscopia eletrônica de varredura (MEV). O exame macroscópico evidenciou uma massa tumoral que se estendia do rebordo alveolar do maxilar superior à face externa labial. À MEV, a neoplasia apresentou uma série de espículas. Microscopicamente, percebia-se um processo neoplásico constituído por tecido conjuntivo de característica mixoide, ricamente vascularizado, onde eram observados fragmentos de tecido osteoide. A amostra revelou proliferação neoplásica do epitélio odontogênico, onde as células neoplásicas se organizavam na forma de paliçada. Alterações histopatológicas em peixes têm sido úteis biomarcadores do efeito à exposição a substâncias tóxicas, sendo as neoplasias lesões específicas, comumente encontradas em peixes de áreas poluídas, revelando uma associação entre as lesões e a exposição a irritantes.

Anaesthetic efficacy of eugenol was investigated on Pterophyllum scalare. A total of 130 fish with average weights of 1.0 ± 0.5, 5.0 ± 1.0 and 10.0 ± 1.0 g were subjected to 1.25, 2.5, 4.0, 5.5 and 7.0 mg/L eugenol, and behavioural responses were observed. Induction and recovery times were significantly affected by the interactive effect of eugenol concentration and fish weight ( p < .05). Generally, 49.9-128 s after exposure to 1.25-7 mg/L eugenol, fish reached stage 3. Fish entered stage 4 over 55-135 s post exposure to such concentrations. Recovery time was 393.5-597.7 s in all sizes. Any increase in eugenol concentration led to a significant decrease in the induction time with a subsequent increment of the recovery time. Concentrations of eugenol and fish size along with their interactive effects have significantly contributed to the regression models, with concentration recording the highest beta values for stages 1, 2, 3 and 4 (−0.903, −0.898, −0.976 and −0.864 respectively) and the product of size and anaesthetic concentration for full recovery in smaller fish (0.647) and eugenol concentration in larger ones (0.967). Recovery time was fitted to induction time to stage 4 via quadratic and linear regression models in smaller and larger fish respectively. Results revealed the minimal eugenol concentration to induce anaesthesia in various size classes of angelfish in less than 3 min was 1.25 mg/L. Our results showed eugenol as an effective and safe anaesthetic; however, it is not advisable for live fish transportation. [ABSTRACT FROM AUTHOR]

The study was conducted to evaluate the effect of different stocking densities on the growth and survival of angelfish, Pterophyllum scalare fry reared in all-glass tanks with under-gravel filtration system. In the experiment, angelfish fry with length and weight in the range of of 1.3-1.6 cm and 0.060-0.076 g were reared at different densities, i.e. 3 fry L-1, 2 fry L-1, 1 fry L-1 and 0.5 fry L-1 for a period of 45 days in all glass tanks (36 L) with undergravel filtration system. The experiment was conducted according to completely randomized design with four replicates for each density. The freshwater was added to compensate evaporative water loss from the tanks, but no water exchange was carried out in the experimental tanks. Fry were fed flake feed containing 49.02% crude protein. The fry reared at the density of 0.5 fry L-1 showed significantly (P<0.05) higher length gain (153.6593%), weight gain (967.5915%) and specific growth rate (5.2622%) than that of fry reared at other densities. The densities of 0.5 and 0.1 fry L-1 resulted in 100% survival which was found significantly better (P<0.05) than that of fry reared at densities of 2 and 3 fry L-1. Decreased growth was observed with increase in stocking density. However, due to use of under gravel filtration system water quality parameters were found to be in optimal range for certain period at different stocking densities. Hence, water quality and consequently fish production of angel fish fry in aquaria can be optimized with the stocking density of 0.5 and 0.1 fry L-1 with use of under gravel filtration system. [ABSTRACT FROM AUTHOR]

Dietary protein and energy requirements of juvenile freshwater angelfish (Pterophyllum scalare) were evaluated. A 3 × 2 factorial design was used, with three dietary crude protein levels being tested (26, 30, and 34% of CP) combined with two digestible energy levels (3,100 and 3,300 kcal DE/kg of diet) in three replicates. Juveniles averaging 2.33 ± 0.26 g were reared in a 25L-aquarium with controlled temperature (26 ± 1ºC), biological filter and stocking density of six fish/aquarium. Fish were fed ad libitum at 09:00 a.m., 2:00 p.m. and 4:30 p.m. The following performance parameters were evaluated: final weight, final length, weight gain, feed intake, feed conversion ratio, specific growth rate, protein efficiency ratio and condition factor. Fish fed diets with 26% CP showed greater protein efficiency values when compared to those fed diets with 34% CP. Diets with 26% of CP and 3100 kcal DE/kg could meet the nutritional requirements of juvenile freshwater angelfish.Avaliaram-se as exigências nutricionais de proteína e energia em juvenis de acará-bandeira (Pterophyllum scalare). Utilizou-se delineamento inteiramente casualizado, em esquema fatorial 3 × 2, com três níveis de proteína bruta (26, 30 e 34%), dois de energia digestível (3.100 e 3.300 kcal/kg de ração) e três repetições. Juvenis com peso médio de 2,33 ± 0,26 g foram distribuídos em aquários contendo 25 litros de água, temperatura controlada (26 ± 1ºC) e filtro biológico, na densidade de estocagem de seis animais por aquário. Os peixes foram alimentados à vontade às 9, 14 e 16h30. Na análise do desempenho produtivo, foram avaliados o peso final, o comprimento final, o ganho de peso, o consumo de ração, a conversão alimentar, a taxa de crescimento específico, a taxa de eficiência protéica e o fator de condição. As dietas contendo 26% PB proporcionaram maiores valores para taxa de eficiência protéica apenas em relação às dietas contendo 34% PB. As exigências nutricionais de proteína e energia em juvenis de acará-bandeira podem ser atendidas com dietas contendo 26% PB e 3.100 kcal ED/kg.

Neste estudo, avaliaram-se as exigências nutricionais de proteína para alevinos de acará-bandeira. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro tratamentos (34, 38, 42 e 46% de PB) e quatro repetições. Alevinos (0,44 ± 0,05 g) foram distribuídos em 16 aquários com volume individual de 25 L, dotados de sistema de filtragem, aeração e controle de temperatura (26 ± 0,5ºC), em densidade de estocagem de seis peixes/aquário, onde foram alimentados à vontade, às 8, 11, 14 e 17 h, durante 60 dias. Os parâmetros de desempenho produtivo avaliados foram: peso final, ganho de peso, consumo de ração, conversão alimentar, taxa de crescimento específico e taxa de eficiência protéica (TEP). Ao final do experimento, não foi observado efeito significativo dos tratamentos sobre o desempenho produtivo, exceto para a TEP. A dieta com 46% de PB resultou em TEP significativamente menor que as dietas com 34 e 38% PB, enquanto a dieta com 42% de PB não diferiu das demais. Dietas contendo 34% de PB atendem às exigências nutricionais em proteína de alevinos de acará-bandeira.The aim of this experiment was to evaluate dietary protein requirements of freshwater angelfish fry. A complete randomized design with four dietary crude protein levels (34, 38, 42, and 46% of CP) and four replicates was used. Fish averaging 0.44±0.05 g were reared in sixteen 25L-aquarium with aeration, biological filter and controlled temperature (26 ± 0.5°C), in a stocking density of six fish/aquarium. Fish were fed ad libitum at 8:00 a.m., 11:00 a.m., 2:00 p.m, and 5:00 p.m, during 60 days. Final weight, weight gain, feed intake, feed:gain ratio, specific growth rate and protein efficiency ratio (PER) were the evaluated parameters of productive performance. At the end of the experiment, no treatment effect on productive performance, with the exception of PER was observed. Fishes fed diets with 46% CP showed PER significant smaller than those fed diets with 34 and 38% of CP. PER of fish fed diets with 42% of CP did not differ from the other treatments. Diets with 34% of CP can meet the protein nutritional requirements of freshwater angelfish fry.

The article reports on the possibilities of whether freshwater aquaculture model can be used for marine drug discovery. The high rate of mortality in production of most fish species and treatment of infections offish eggs is discussed. The study is done in the new freshwater aquaculture model for drug discovery.

Angelfish (Pterophyllum scalare, 1.54±0.03 g, n=500) were exposed for 24, 48, 72 and 96 hours to different concentrations NH3-N (0.2-2 mg/L), and NO2-N (1-35 mg/L) at pH 7.2±0.3. Using Probit analysis, 50% lethal concentrations (LC50) and 95% confidence limits were calculated. The effects of ammonia (0.7 mg NH3-N/L and 10 mg NO2-N/L) nitrite to the red blood cells size were also investigated in this study. As a result of the study, 24, 48, 72 and 96 hours LC50 values of ammonia nitrogen (NH3-N) for angelfish were determined as 0.99, 0.75, 0.65 and 0.58 mg/L; and nitrite nitrogen (NO2-N) values were calculated as 29.38, 12.30, 7.98 and 6.28 mg/L. respectively. In the examination of blood smear, red blood cells were determined oval shaped (erythrocytes and its nuclei size), and their sizes were measured and evaluated as long and short axes. It was also determined that, exposed to ammonia and nitrite, erythrocyte morphology had changed that was statistically different from each other (P<0.05). [ABSTRACT FROM AUTHOR]

Angelfish (Pterophyllum scalare) is a very important species in Brazil's domestic market, however feeding managements differ from fish breeders to aquarists, so the cost of feed and labor become relevant items when cultivating the species. The objective of this research was to assess feeding frequency and feed deprivation based on growth performance, parasite infestation and costbenefit in farming this species. The experiment was conducted in a completely randomized design in a 3x2 factorial scheme with 3 daily feeding levels, 4 meals, 2 meals and 1 meal; with and without feed deprivation and two repetitions. Feed deprivation consisted of offering feed 5 days a week only. Feeding twice a day without deprivation and four times a day with or without feed deprivation resulted in higher growth performance than feeding once a day. Monogenean and nematode parasitic loads were not influenced by feeding management. The cost-benefit analysis enabled us to observe that the treatment with the best benefit was the one involving two feedings a day with no deprivation. Thus, considering the parameters mentioned above, we concluded that the two daily feedings with no feed deprivation is the most adequate for farming this specie. [ABSTRACT FROM AUTHOR]

O experimento foi conduzido na Universidade Estadual Paulista, Laboratório de Peixes Ornamentais do Centro de Aqüicultura da Unesp, Jaboticabal, Estado de São Paulo, com o objetivo de avaliar o desempenho produtivo do acará bandeira (Pterophyllum scalare), alimentados com dietas processadas de três formas (farelada, eletizada e extrusada). Foram utilizados 240 peixes distribuídos em 24 aquários de 40 L, alimentados com uma dieta contendo 28% de PB e 4000 kcal kg-1 de EB. Avaliou-se o peso final médio, ganho de peso,taxa de crescimento específico, consumo de ração e conversão alimentar. Ao final de oito semanas, não houve diferença significativa no desenvolvimento dos peixes alimentados comdietas extrusada e peletizada. Os alimentados, entretanto, com dieta farelada apresentaram baixa taxa de crescimento específico. A taxa de conversão alimentar foi melhor em indivíduos alimentados com dieta extrusada. Nas condições presentes neste estudo dietas extrusadas epeletizadas são adequadas para o crescimento e manutenção do acará.The experiment was conducted in the Laboratory of Ornamental Fishat the Aquaculture Center of Unesp, State of São Paulo, Brazil, aiming to evaluate the growth performance of the angelfish (Pterophyllum scalare) fed with three different diets (pelleting,extruding and grinding). Two hundred forty fish were stocked in 24 aquaria (40 L) and fed with a diet of 4000 kcal kg-1, crude energy and 28% crude protein. The final mean weight, weight gain, specific growth rate, feed intake and feed conversion were evaluated. After 8weeks there was no difference on angelfish fed with extruded and pelleted diet. However fish fed with grinded diet presented poor growth and the specific growth rate was smaller. The feed conversion ratio had better values in fish fed with extruded diet. It was concluded that both extruded and pelleted diets were suitable for growth and maintenance of angelfish.

Se investigó el crecimiento, conversión alimenticia (FCR), sobrevivencia y resistencia al estrés de juveniles del pez ángel Pterophyllum scalare, alimentados con diferentes dietas inertes (quistes decapsulados de Artemia DAC, hojuelas comerciales CF, pelets comerciales CP y una dieta comercial iniciadora para tilapia CSDT). Las dietas fueron estudiadas con tres réplicas y la ración alimenticia fue ajustada al 8% de la biomasa total. Los peces pesaron 0.44 g en promedio, al inicio. Las dietas mostraron un efecto significativo sobre el crecimiento de los peces desde la primera biometría. Después de 45 días de cultivo, los peces alimentados con DAC mostraron los valores promedio más altos en la longitud estándar, peso húmedo y crecimiento específico (3.64 ± 0.07 cm, 3.19 ± 0.24 g y 4.36 % peso corporal/ día, respectivamente), comparado con el resto de los tratamientos. El FCR fluctuó desde 1.26 ± 0.01 para el grupo DAC, hasta 2.01 ± 0.17 para la dieta CP, mostrando diferencias significativas (P < 0.05) entre los tratamientos. La sobrevivencia fue similar para todas las dietas. Los peces alimentados con DAC mostraron la mayor resistencia al estrés comparado con el resto de los tratamientos. Aunque la dieta DAC mejoró el crecimiento de los juveniles del pez ángel, se requieren de estudios posteriores para identificar algunos factores (biología nutricional, técnicas y estrategias de alimentación) asociados a su mejor uso económico

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Gussevia spiralocirra, a Neotropical parasitic monogenoid (Platyhelminthes), has been recorded from the type host, freshwater angelfish Pterophyllum scalare (Cichlidae), collected from the post-quarantine populations in local aquarium markets of Lucknow and Itanagar, India. The finding establishes India as a geographical distribution record for G. spiralocirra, and more importantly, reveals a potentially serious breach of quarantine regulations of the country. The present communication provides a summary assessment of existing Indian guidelines for importation of exotic aquarium fish and highlights some of its major shortcomings. [ABSTRACT FROM AUTHOR]