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In view of the need to improve the development of family production enterprises, zootechnical and economic planning were conducted in a rural settlement in 0.78 ha of water depth for the rearing and marketing of juveniles of the tambatinga hybrid (♀ tambaqui Colossoma macropomum x ♂ pirapitinga Piaractus brachypomus) to verify its economic viability. For the zootechnical indicators, a 16-month production cycle was determined, with three juvenile production cycles and two fattening cycles. For the remaining fish that were not sold, the quantity of initial and final fish, stock biomass, average initial and final weight, apparent feed conversion, and mortality rate were determined. For economic planning, a total operating cost methodology was adopted to determine the costs per unit of production, gross revenue, gross margin, net profit, and profitability index. The production of juveniles of many sizes is economically viable for family farming, showing attractive profitability indicators even under adverse zootechnical conditions. This study demonstrated the effectiveness of zootechnical and economic planning on a property that can optimize production and use of the area, as well as showing producers how rewarding it is to farm fish.

Abstract In the aquaculture industry, biocides are routinely used to treat parasitosis in fish, and researchers are continually developing sustainable alternatives that can replace these harsh chemicals. In this context, the objective of this study was to evaluate the effectiveness of a new natural compound, BiokosTM, for the treatment against Epistylis sp. in Carassius auratus fish. The infestation was identified by the presence of whitish plaques on the integument of five animals, and the diagnosis was confirmed through skin scrapings. BiokosTM is a lipopeptide derived from the bacteria Pseudomonas that can destroy the functionality of the cell membrane of ciliated protozoa. The action of BiokosTM does not harm animals and the environment because the compound degrades into amino acids and fatty acids within days. A 0.15 m3 (150 L) aquarium was treated with an Ich-AwayTM water conditioner manufactured by the Danish company Sundew ApS, which has BiokosTM as the active ingredient. Six tablets were added to the water daily for two days, and new skin scrapings were performed. The fish were clinically well and no longer possessed lesions or parasites. The results obtained indicate that BiokosTM can be an innovative and more sustainable alternative for controlling epistyliasis in ornamental fish.

We aimed to identify the digestive microbiota of the golden mussel Limnoperna fortunei, and characterize its structure in different seasons. Limnoperna fortunei specimens were sampled in winter (September 2019) and summer (March 2020) in five reservoirs of hydroelectric power plants in southern Brazil. In each reservoir, we sampled 15 individuals at three different points. We collected the digestive diverticulum and portions of the intestine for bacterial DNA extraction, and subsequently conducted metagenomic analysis. The intestinal microbial communities of L. fortunei occurring in the upper Uruguay River region showed significant differences during winter and summer. Although the phyla Proteobacteria, Bacteroidetes, and Cyanobacteria were dominant regardless of the season, the microbial communities showed greater richness and bacterial diversity in the summer. Additionally, we found 143 species of bacteria in the digestive samples collected during both winter and summer, which may indicate a central microbial community for the species. The microbial communities in the digestive tract of L. fortunei showed greater bacterial richness and diversity in summer samples, which existed at a significantly higher temperature than those in winter samples. We observed seasonal variations in the microbiota of L. fortunei in the upper Uruguay River region, with increased bacterial richness and diversity in the digestive tract during summer, attributed to higher temperatures. However, Proteobacteria, Bacteroidetes, and Cyanobacteria consistently dominated the digestive tract of the golden mussel, regardless of seasonal fluctuations.

Abstract The hematological parameters of fish contribute to the understanding of the health status in response to diseases, treatments, handling, and environmental factors. This study aimed to verify the hematological parameters of mullet Mugil liza after one-hour immersion baths in five concentrations of hydrogen peroxide (H2O2), an effective chemical treatment for several diseases in fish. A total of 108 fish (35.25 ± 6.09g) was distributed into six treatments with three replicates each: untreated fish (control), and fish treated with five concentrations of H2O2 (150, 200, 250, 300 and 350 mg L-1). Blood collection was performed immediately after bathing and 30 days after. Erythrogram, leukogram, thrombocytogram, hematocrit, plasma glucose, hemoglobin concentration and hematimetric indexes were analyzed. There was no significant difference in the erythrocyte and total leukocyte counts. Regarding plasma glucose and hematimetric indexes, the values were increased (p

We herein evaluated the hematology and parasitology of Nile tilapia previously raised in an earthen pond and transferred to a recirculating aquaculture system (RAS) to verify any possible influence of RAS on such health parameters. For this, 780 tilapias with an initial average weight and length of 91.05 ± 27.08 g and 17.45 ± 1.91 cm, respectively, were distributed in three tanks (2.0 m3) attached to the RAS, where they remained for 54 d. Throughout the period, water quality parameters remained within the range suitable for the cultivation of the species. Tilapia growth performance was satisfactory in the RAS, reaching a final biomass of close to 300 kg and survival of 98%. Hematological and parasitological analyses at the end of 54 d showed possible stress in RAS, with a significant increase in neutrophils from 12.15 ± 6.66 (earthen pond) to 21.43 ± 11.68% (RAS) and erythrocytes from 1.81 ± 0.24 (earthen pond) to 2.13 ± 0.14 (RAS), and a significant decrease in lymphocytes from 22.4 ± 2.66 (earthen pond) to 13.67 ± 3.38 (RAS). Furthermore, parasitological analysis showed a significant increase in the number of parasitized fish (25% to 63%) and abundance (3.55 ± 6.44 to 9.37 ± 9.99) after 54 d. It was concluded that tilapia cultivation in RAS can cause hematological changes and increase parasitism.

Despite all the technical-scientific knowledge about streptococcosis, the high prevalence of bacterial infections caused by Streptococcus spp. in Nile tilapia farming implies the frequent, often irresponsible, use of antibiotics. The use of chemotherapy in aquaculture environments remains an efficient practice in the treatment of bacterial infections and disease prevention. Research have shown that the emergence of antimicrobial resistance (AMR) in farmed fish is one of the main challenges faced in aquaculture. It is known that emerging AMR in aquaculture can be transferred to clinically important strains from the natural environment through horizontal gene transfer (HGT) affecting the entire aquatic ecosystem. Maintaining health in tilapia farms promotes the sustainability of production systems and, consequently, improves the final quality of farm products. Therefore, the objective of this review was to provide information on the prevention, control and eradication of diseases in Nile tilapia farms, and how such management plays a fundamental role in maintaining public health by ensuring adequate sanitary conditions for animals intended for human consumption.

The aim of this study was to evaluate the effect of supplementing feed with a functional mixture of immunomodulators, including β-glucans, nucleotides, ascorbic acid, and alpha-tocopherol, associated with a diet with lower levels of animal protein (11.5%) and higher levels of soybean meal (43.5%), on the zootechnical performance, health, hematological and immunological parameters, intestinal morphology, centesimal composition, and intestinal microbiome of juvenile Nile tilapia (initial weight 1.88 g ± 0.25 g, mean ± standard deviation). Two isocaloric and isoproteic diets (35% crude protein) were formulated, one with the inclusion of the immunostimulant functional mixture (40 kg·t−1), composed of 150 mg·kg−1 of nucleotides, 1000 mg·kg−1 of β-glucans, 1000 mg·kg−1 of ascorbic acid (vitamin C), and 20 mg·kg−1 of alpha-tocopherol (vitamin E), and another without. The combined supplementation of nucleotides, β-glucans, ascorbic acid, and alpha-tocopherol resulted in a 59.95% increase in final weight, 64% weight gain, 66% daily gain, a 21.31% decrease in feed conversion rate, and double the retention of body protein. Supplementation also improved intestinal morphology and modulated the intestinal microbiome, increasing Chao-1 diversity. Transmission electron microscopy confirmed that fish fed with both diets exhibited intact intestinal mucosal membranes. Supplementation did not alter the hematological and immunological parameters, suggesting that there was no overstimulation of the fish’s immune system. This work allows us to evaluate the effect of reducing the use of animal protein in the diets of fish, along with the effects of nucleotides, β-glucans, ascorbic acid, and alpha-tocopherol. Together, these compounds can provide fish with the necessary tools to achieve optimal health and growth.

The aim of this study was to isolate and identify Aeromonas species, characterize their virulence genes factors, and to evaluate their lethality in Piaractus brachypomus. Presumptive Aeromonas (n = 34) were selected from 44 bacteria retrieved from diseased Amazonian fish. Nineteen isolates were chosen based on fish species, group, the location where were isolated, and colony morphology. Isolates were biochemically and molecularly identified as Aeromonas hydrophila, A. dhakensis, A. veronii, A. jandaei, and A. caviae using API 20E, API 20NE and the analysis of 16 S rRNA and gyrB genes, respectively. Eight virulences genes (aer, altA, act, hly, ser, lip, fla ahyB) were found in one A. dhakensis and two A. hydrophila isolates. A. veronii, A. jandaei, and another two A. hydrophila isolates harbored four, two and three virulence genes, respectively. All A. caviae were fla +, ahyB + and lip +, except two isolates that also presented ser and altA. P. brachypomus (9 ± 1 cm), infected intraperitoneally (4 ×106, 4 ×107, and 4 ×108 CFU/fish), showed susceptibility to all Aeromonas species, each harboring a different virulence genes profile. Both A. hydrophila and A. dhakensis caused > 80% mortality at the lowest evaluated concentration (∼106 CFU/fish). A. veronii and A. jandaei isolates produced 20% and 70% mortality, respectively, using ∼107 CFU/fish, but with lower intensity compared to A. hydrophila and A. dhakensis. At the highest concentration (∼108 CFU/fish), A. veronii caused 70% mortality, while A. caviae isolates caused mortality ranging from 50% to 80%. Remarkably, A. jandei resulted in 100% mortality at this level, similar to A. hydrophila and A. dhakensis. This report confirms the variety of Aeromonas species infecting farmed native Amazonian fish. The study also suggests that virulence genes evaluated in Aeromonas species may not always be an indicator of virulence. Moreover, P. brachypomus, an economically important aquaculture fish species could be susceptible not only to the high mentioned A. hydrophila but also to other less observed species such as A. dhakensis, A. veronii, A. jandaei, and A. caviae, bacteria that should be taken into account in health surveillance for the implementation of aquaculture disease prevention strategies.

The aim of this study was to observe how abiotic and biotic factors in a tropical region influence the rate of monogenean parasitism in Nile tilapia (Oreochromis niloticus) that are farmed in net cages. A total of 240 sexually reversed fish were analyzed, and 20 from each culture stage were collected during each sampling month. Overall, 60 fish were sampled in April (autumn), 60 in August (winter), 60 in November (spring), and 60 in February (summer). Fish were collected from a commercial fish farm located in Capivara Reservoir in the lower Paranapanema River region of Paraná, Brazil. In total, 3290 monogenean parasites were collected from fish gills of the following species: Cichlidogyrushalli, C. thurstonae, Scutogyruslongicornis, C. cirratus, C. sclerosus, and C. tilapiae. Higher parasitological indices were observed in colder seasons with lower precipitation. Autumn had the highest parasitic infection values compared to the other seasons. The occurrence of monogenean parasites showed a negative correlation with season, in contrast to the culture stage, in which there was a positive correlation. These results may provide a means for establishing adequate fish farm management to predict periods of high monogenean infestation.

Abstract The genus Dermocystidium infects a wide range of animals. The host infection often occurs through the ingestion of endospores. The diagnosis depends on wet mounts and histopathological analysis of the affected tissue. The aim of this study was to investigate the incidence of Dermocystidium sp. infection on the skin of farmed striped catfish (Pangasianodon hypophthalmus) from a fish farm located in Fortaleza, Ceará state, northeastern Brazil. From these observations, we determined that 100% of the analyzed animals were infected with Dermocystidium sp. The wet mount and histopathology of the fish lesions revealed spore-filled cysts between the dermis and epidermis, encapsulated by connective tissue. Owing to a lack of research on the parasite and its prevalence among different fish species in Brazil and the rest of the world, additional studies are required to understand their endemicity in fish farms of Brazil, and consequently develop better disease prevention methods and increase the overall productivity.

The essential oil of alfavaca (Ocimum gratissimum) contains important compounds, such as 1.8-cineol and eugenol. This study evaluated the effects of diets containing alfavaca essential oil on the zootechnical performance, plasma glucose, leukocyte respiratory activity, haematology, and intestinal histomorphometry in “cachara” (Pseudoplatystoma reticulatum) challenged with Aeromonas hydrophila. A total of 300 juvenile fish, with an average total length of 14.98 ± 0.28 cm and average weight of 18.84 ± 1.22 g, distributed in 20 tanks of 80 L, were fed twice a day with a diet containing essential oil at 0.5, 1.0, or 1.5% or without its inclusion in five replicates. After 45 days, blood collection and mid-intestinal bowel were sampled, before a challenge with Aeromonas hydrophila was performed. The fish supplemented with 1.0% of essential oil presented better weight gain, mean corpuscular volume, concentration of thrombotic and neutrophils, respiratory activity of leukocytes, and height of villi (p < 0.05) when compared to other groups. The cumulative mortality response was lower for fish fed 1.5% essential oil of alfavaca diets. Thus, the use of alfavaca essential oil is recommended in the diet of cachara catfish (P. reticulatum) at the level of up to 1.0% for 45 days for improvements in the zootechnical, haematological, and intestinal histomorphometric parameters.

Abstract Ascocotyle (Phagicola) longa is an etiological agent of human phagicolosis. Mugilids are the second intermediate host, the first being Heleobia australis, and mugilids predatory birds and mammals are its definitive hosts. The occurrence of cysts holding A. longa metacercariae is described in mugilids with a prevalence of up to 100%. The wide geographical distribution of A. longa and its intermediate hosts coupled with the rise in the consumption of raw or poorly cooked fish may elevate the risk of human infection. Therefore, in this study, we aimed to verify the distribution pattern of cysts holding A. longa in mugilids. The tissue and organ samples of these fish were processed in a domestic blender and examined under a stereoscopic microscope to identify the cysts holding the digenetic metacercariae. Of the 24 (100%) fish samples that were analyzed, 12 of Mugil curema and 12 of Mugil liza possessed cysts holding A. longa metacercariae. Digenetic cysts were identified to be present in the gills, heart, stomach, liver, intestines, mesentery, and muscular tissues collected from M. curema and M. liza. Conclusively, in M. curema, the cysts holding A. longa metacercariae were found to be distributed randomly throughout the fish body in almost every tissue and organ that was examined.

This study aimed to evaluate the effects of essential oil (EO) of Lippia sidoides, Ocimum gratissimum, and Zingiber officinale in the diet of tambaqui (Colossoma macropomum) growth, hematological and immunological parameters. The survival rate was also calculated after challenge with Aeromonas hydrophila. Seven diets containing 32 % crude protein were formulated as follows: control (0 g/kg of EO), 0.625 and 1.25 g/kg of L. sidoides EO; 1.25 and 5.0 g/kg of O. gratissimum EO; 1.25 and 5.0 g/kg of Z. officinale EO, in triplicate. Tambaqui fed diets supplemented with EO of L. sidoides, O. gratissimum, and Z. officinale did not present significant differences in the growth parameters. After 30 and 60 days of feeding, performance and hematological parameters were evaluated. Reductions in total thrombocytes number occurred after 30 days of feeding with 1.25 g/kg and 5.0 g/kg O. gratissimum EO. After 60 days of feeding, fish were challenged with A. hydrophila (1.6 × 108 UFC mL−1) and were observed for 10 days. Fish fed with diets supplemented with L. sidoides EO at 0.625 g/kg and 1.25 g/kg showed a higher nonspecific immune response through the increased respiratory activity of leukocytes after challenge. Additionally, there was a decrease in plasma glucose levels and no alteration of the total protein levels. Moreover, after the challenge, the highest survival rate occurred among fish fed 0.625 g/kg L. sidoides EO, while treatments with O. gratissimum and Z. officinale EO did not affect fish survival. This is the first report of L. sidoides EO in tambaqui diets. More studies are warranted to adjust the concentration and periods of treatment regarding diets supplemented with L. sidoides EO or thymol in treatment of bacterial fish diseases.

This study evaluated the in vitro and in vivo parasiticidal efficacy of the essential oils of Mentha piperita, Lippia alba and Zingiber officinale on Neoechinorhynchus buttnerae (acanthocephalan) and their effect when used as dietary supplementation on hematological parameters of Colossoma macropomum. For the in vitro assay, the parasites were exposed to five different concentrations (360, 540, 720, 1440, and 2880 mg L−1) of the essential oils diluted in 3% Tween 80, for incubation period of 24 hs observed each 15 min. The essential oil of M. piperita caused mortality of 100 % of the parasites in 2 h in the concentration (540 mg L−1), compared to the essential oils of L. alba and Z. officinale. For the in vivo tests, 210 juvenile tambaqui were used; they were fed for 30 days with either the control diet and experimental diets consisting of supplementation with essential oils: control, M. piperita 0.54 g kg−1 and 2.88 g kg−1, L. alba 1.44 g kg-1 and 2.88 g kg−1, Z. officinale 1.44 g kg−1 and 2.88 g kg−1, in triplicate, resulting in 21 experimental units (10 fish per tank). The anthelmintic activity in the animals treated using diets supplemented with M. piperita at 0.54 and 2.88 g kg−1 were 85.46 % and 70.03 %; with L. alba 1.44 and 2.88 g kg−1 were 67.10 % and 56.93 %, and with Z. officinale 1.44 and 2.88 g kg−1 were 11.70 % and 5.19 %, respectively. Total red blood cells count and thrombocytes were higher in fish treated with M. piperita at 0.54 g kg−1 and Z. officinale at 1.44 g kg−1. The supplementation with essential oil of M. piperita at 0.54 g kg−1 was effective in the control of N. buttnerae and presented better specific growth rate. However, despite these promising results, more research is needed to validate their use in commercial production.

Abstract This study identified the parasitic species in juvenile freshwater finfishes during the fattening stage, from a fish farm located in the Zona da Mata (MG), southeastern Brazil, and revealed both macro and microscopical lesions in fish gills. A total of 172 juvenile fishes of different species (Oreochromis niloticus, Ictalurus punctatus, Ctenopharyngodon idella, Cyprinus carpio, Astyanax bimaculatus and Brycon amazonicus) were transported to a laboratory in São Paulo city. The fish were sedated and then euthanized for parasitological analysis. All fish were infected by at least one parasite species. Ten different species of parasites were identified: Apiosoma sp., Epistylis sp., Ichthyobodo sp., trichodinids, Piscinoodinium pillulare, Ichthyophthirius multifiliis, Tetrahymena sp., monogeneans, Centrocestus formosanus metacercariae, and Dermocystidium sp. The best management practices and lack of sanitary control were also discussed.

Abstract: Aim The increment of decomposition of organic matter in sediment samples from Nile tilapia farms was evaluated with the introduction of Bacillus subtilis and B. licheniformis bacteria. Methods Sediment samples placed in 18L plastic boxes received single dose inoculum with the following concentrations: 1.21 x 106 CFU g-1 (equivalent to 75 g ha-1), 2.41 x 106 CFU g-1 (equivalent to 150 g ha-1), 4.82 x 106 CFU g-1 (equivalent to 300 g ha-1) and 1.61 x 107 CFU g-1 (equivalent to 1000 g ha-1), in addition to a control treatment with saline solution only. Organic matter content, total organic carbon (TOC) and oxidizable (OOC), total nitrogen (TN), ratios (TOC: N and OOC: N), clay content, pH in water, Shoemaker, McLean, Pratt index (SMP Index), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) contents, potential acidity (H + Al), cation exchange capacity (CEC) at pH 7.0, base saturation (V) and sum of bases (S). Results The values of OM showed significant difference, between the lowest values (treatments 75, 150 and 300 g ha-1) and the highest value, (control treatment). TOC, OOC, NT and their relationships (TOC: N and OOC: N) showed significant differences between the mean values of the control treatment and the other treatments. Conclusions The addition of Bacillus subtilis and B. licheniformis bacteria increased the decomposition rate of organic matter in sediments samples from Nile tilapia farms.

Abstract This study evaluated the parasitic fauna of hybrids tambacu (Colossoma macropomum × Piaractus mesopotamicus) and patinga (P. mesopotamicus × Piaractus brachypomus) and their host-parasite-environment interaction during the warm and cold seasons in two fish farms located in the State of Mato Grosso do Sul, Brazil, South America. A total of 120 fish, being 60 fish for species (30 in the warm season and 30 in the cold season) were examined. Water quality was measured weekly to evaluate the interaction between environmental conditions and parasitism. Fifteen species of parasites were found: Ichthyophthirius multifiliis, Chilodonella hexasticha e Trichodina sp. (Protozoa), Henneguya piaractus, Myxobolus colossomatis and Myxobolus cuneus (Myxozoa); Anacanthorus penilabiatus, Mymarothecium boegeri, Mymarothecium viatorum, and Notozothecium janauachensis (Monogenoidea), Goezia spinulosa and Goezia sp. (Nematoda), Echinorhynchus jucundus (Acanthocephala), and Dolops carvalhoi, Lernaea cyprinacea (Crustacea). The ciliate protozoan I. multifiliis and monogenoids were the most prevalent parasites in the cold and warm seasons for both hybrids in the different culture systems intensive production and sportive fishing. It was observed that the serrasalmid hybrids are more susceptible to parasites and harbor high diversity of parasites in relation to the parental species C. macropomum, P. mesopotamicus and P. brachypomus, with a predominance of ectoparasites.

Abstract More than 1.450 marine fish species are commercialized as ornamental fish and approximately 90% of these are wild-caught. Rainford's butterflyfish, Chaetodon rainfordi (McCulloch, 1923), is endemic to the western Pacific. This fish species belongs to one of the main ornamental fish families imported into Brazil. Haliotrema is a genus of the family Dactylogyridae. Species of this genus have very interesting host associations and geographic distributions. The aim of this study was to report on occurrences of exotic Haliotrema aurigae in diseased Rainford butterflyfish that were imported to Brazil. One Rainford’s butterflyfish with suspected parasitic disease was euthanized and subjected to skin and gill scraping. The parasite specimens were mounted on semi-permanent slides with Hoyer’s solution for morphological analysis of sclerotized structures. The hard-sclerotized structures of these specimens were compared and were identified as those of Haliotrema aurigae (Yamaguti, 1968). These results emphasize the importance of implementation of correct control measures at the country’s borders, to avoid the introduction of exotic parasites. In addition, it can be emphasized that the easy adaptation of this parasite to new environments is a concern for ornamental fish farmers.

Abstract Scuticociliatosis, caused by an opportunistic ciliate protozoan, is responsible for significant economic losses in marine ornamental fish. This study reports the occurrence of Uronema spp., parasitizing ten species of marine reef fish at an ornamental fish wholesaler: Blue green damselfish (Chromis viridis), Vanderbilt’s Chromis (Chromis vanderbilti), Pennant coralfish (Heniochus acuminatus), Threespot angelfish (Apolemichthys trimaculatus), Goldspotted angelfish (Apolemichthys xanthopunctatus), Sea goldie (Pseudanthias squamipinnis), Orchid dottyback (Pseudochromis fridmani), Threadfin butterflyfish (Chaetodon auriga), Vagabond butterflyfish (Chaetodon vagabundus), and Bluecheek butterflyfish (Chaetodon semilarvatus). Diseased fish showed disorders such as hemorrhages and ulcerative lesions on the body surface. Histopathological analysis of the muscle, liver, gut, kidney, spleen, gills, and stomach revealed hemorrhages and degeneration of muscle fiber, vacuolar degeneration of hepatocyte, inflammatory process and granuloma in the liver, atrophy of intestinal villi, inflammatory process and granuloma in the kidney, melanomacrophage centers, as well as inflammatory process in the spleen, epithelial cells hyperplasia and granuloma formation in the gills, and vacuolar degeneration and eosinophils in the stomach. Due to the severity of the disease, it is necessary to implement biosecurity measures with rapid and accurate diagnosis to minimize the risk of economic losses caused by Uronema spp.

Abstract Infection by the acantocephalan Neoechinorhynchus buttnerae is considered one of most important concerns for tambaqui fish (Colossoma macropomum ) production. Treatment strategies have been the focus of several in vivo studies; however, few studies have been undertaken on in vitro protocols for parasite maintenance. The aim of the present study was to develop the best in vitro culture condition for N. buttnerae to ensure its survival and adaptation out of the host to allow for the testing of substances to be used to control the parasite. To achieve this, parasites were collected from naturally infected fish and distributed in 6-well culture plates under the following treatments in triplicate: 0.9% NaCl, sterile tank water, L-15 Leibovitz culture medium, L-15 Leibovitz + agar 2% culture medium, RPMI 1640 culture medium, and RPMI 1640 + agar 2% culture medium. The plates containing the parasites were maintained at 24 °C, 28 °C, and 32 °C. The RPMI 1640 + agar 2% culture medium showed the best survival of 24 days at 24 °C. No body alterations such as swollen parasites, body deformation, dehydration and hardening were observed in the RPMI 1640 + 2% culture medium.

Abstract The aim of this study was to evaluate the impacts of metazoan parasites on hematological and biochemical parameters and relative condition factor of tambaqui (Colossoma macropomum ) farmed in northern Brazil. A total of 32 juvenile fish were captured from a commercial fish farm located in the municipality of Rio Preto da Eva, Amazonas state, Brazil. Parasite prevalence was 100% for Anacanthorus spathulatus, Mymarothecium boegeri and Notozothecium janauachensis, 100% for Neoechinorhynchus buttnerae and 53.13% for Dolops geayi. The greatest mean parasite intensity was found in acantocephalans followed by monogeneans and branchiuran crustaceans. A negative correlation was observed between abundance of N. buttnerae and hematocrit percentage, hemoglobin concentration, total thrombocyte count and glucose and between abundance of the monogenean and glucose concentration. Parasitic infections caused damage in tambaqui in terms of the observed hematological parameters that were characterized by hypochromic anemia and thrombocytopenia, which are important parameters to be used in parasitic diagnosis. This study is the first record of the occurrence of Dolops geayi in farmed tambaqui in the Amazon.

Isopods from the family Cymothoidae are fish ectoparasites displaying low host specificity found commonly attached to the gills, mouth, opercular cavity, nostrils and body surface of several host species. Damage can vary according to the degree of parasitism and the infestation site and may provoke respiratory discomfort in hosts. The aim of this study was to report the occurrence of a Nerocila sp. Leach, 1818 isopod parasitizing Mugil liza Valenciennes, 1836 captured in the Babitonga Bay, Santa Catarina State, Brazil. The female parasite specimen was recovered from the pectoral fin of M. liza and was 24 mm in length and 11 mm in width, and the mean egg size was 1.18 ± 0.08 x 1.03 ± 0.06 mm.

Abstract This study evaluated the parasite fauna of farmed hybrid surubim (Pseudoplatystoma reticulatum x P. corruscans) and the host-parasite-environment relationship in two fish farms located in Mato Grosso do Sul, Central Brazil, South America. A total of 120 hybrids from two different farms, 60 in each season (30 in the hot and 30 in cold season) were examined during a year. Water quality was weekly measured to evaluate the interaction among environmental conditions and parasitism. Histopathology was used to observe the effects of the parasites and environment on the fish gills. The ciliate protozoan Ichthyophthirius multifiliis and the monogeneans (Ameloblastella sp., Amphocleithrium paraguayensis, Vancleaveus ciccinus, V. fungulus and V. janacauensis) were the most prevalent parasites detected in both seasons in both farms, with prevalence above 80%. It was stated that parasites did not cause important damage in the health status of the hybrid surubim. These results might be related to general good management practices and environmental quality implemented by the fish farmers. The presence of uncommon monogenean parasites to this hybrid compared to their parents causing an environmental and ecological concern is here discussed.

Resumo: O objetivo deste trabalho foi analisar a detecção, o controle e a prevenção de fotobacteriose em cultivo de bijupirá. Essa doença é causada pela bactéria Photobacterium damselae, que, juntamente com outros fatores, pode estar sendo responsável pela estagnação no crescimento da produção nacional de bijupirá (Rachycentron canadum). Essa bactéria é considerada um dos principais patógenos de peixes marinhos cultivados, tendo sido responsável por importantes prejuízos econômicos em diversos países. No Brasil, essa bactéria ainda não recebeu a devida importância, apesar de já ter sido detectada como causadora de mortalidades nos cultivos de bijupirá. Photobacterium damselae possui duas subespécies, piscicida e damselae, que podem ser consideradas ameaças sanitárias, respectivamente, em relação à atividade econômica da piscicultura marinha e em relação à saúde humana. Neste trabalho, são apresentadas algumas estratégias de detecção, controle e prevenção. Enfatiza-se, também, a necessidade de um melhor acompanhamento sanitário nos cultivos de bijupirá e a importância da vacinação contra esse patógeno.

Abstract: The objective of this work was to describe the host-Epistylis sp. relationship during infestation on farmed fish. Five Nile tilapia (Oreochromis niloticus) and ten hybrid surubim catfish (Pseudoplatystoma reticulatum x P. corruscans), all diseased, were used for in vivo morphological analysis of sessile peritrichs by contrast microscopy. Fragments of infected tissues were subjected to histological processing and scanning electron microscopy. Epistylis sp. caused hemorrhagic ulcer disease, and cichlids were more prone to develop infestations throughout the body surface due to the attachment of the colonies to the scales, which did not occur with pimelodids. Multifocal granulomatous dermatitis was observed, associated with the hydropic degeneration of the epithelium and to ulcerative areas of necrosis. Microscopic examination showed the presence of bacterial microflora associated to Epistylis sp. peduncles. Therefore, this species can be considered a portal of entry for opportunistic bacteria.

This study investigated bacterial strains with probiotic potential isolated from the middle portion of healthy hybrid surubim catfish foregut (Pseudoplatystoma reticulatum female × P. corruscans male). Twenty surubims weighing 1.5 ± 0.3 kg were used for bacterial isolation. In total, 41 strains of bacteria were selected in vitro. Ten strains had inhibition zones >10 mm against Aeromonas hydrophila. Five of those strains presented inhibition zones > 9 mm against other pathogenic bacteria and reached concentrations greater than 105 CFU mL−1 in tubes containing de Man, Rogosa and Sharpe (MRS) medium. In particular, Weissella cibaria (P36) reached 106 CFU mL−1 in MRS and was able to reduce the pH of the medium to 3.85. In the in vivo intestinal colonization studies, 72 healthy hybrid surubims were fed with a commercial diet supplemented with probiotic W. cibaria for 15 days. Changes in gut community composition were then analyzed, and probiotic profile of W. cibaria was determined molecularly by amplification of rRNA 16S gene was performed using PCR. Compared to control fish, W. cibaria-supplemented fish showed an increase in RBC. These results show the efficacy of our haematological approach to probiotic screening in hybrid sorubim. Keywords: Fish nutrition, Sorubim, Lactic acid bacteria, Weissela cibaria

ABSTRACT: A supplementary diet with the probiotic bacteria Weissella cibaria on the efficacy of surubim hybrid immunization against a specific hemorrhagic septicemia caused by Aeromonas hydrophila was evaluated on the following treatments: fish fed a supplemented probiotic diet, vaccinated fish and vaccinated fish fed a supplemented probiotic diet, and untreated fish (control). Fish from the probiotic treatments were fed a diet containing W. cibaria for 41 days. On the 15th day of the experiment, fish from vaccine treatments were intraperitoneally vaccinated, with posterior oral booster for four days. One week after the oral booster, three fish from each experimental unit were sampled. The probiotic supplementation increased the number of thrombocytes and lysozyme concentration compared with surubim that did not receive W. cibaria in the diet. On the other hand, the vaccination increased agglutination titer, lysozyme concentration, and antimicrobial activity compared with surubim that were not vaccinated. However, there was no interaction between diet with probiotics and vaccination in the surubim hybrid in the analysed parameters.

Abstract The capsalid monogenean Neobenedenia melleni is known as a lethal pathogen for captured marine teleost ornamental fish, if left untreated. This study reports the occurrence of N. melleni parasitizing four species of ornamental reef fish imported into Brazil and maintained in quarantine: Arabian angelfish (Pomacanthus asfur ), yellowbar angelfish (Pomacanthus maculosus), regal angelfish (Pygoplites diacanthus), and bluecheek butterflyfish (Chaetodon semilarvatus). Ten days after the beginning of quarantine, some fish showed behavioral alterations, such as irritability, and corneal opacity, which were rapidly diagnosed to be caused by monogenean parasites by body surface scraping. The fish from the same batch were treated with two applications of 2 mg L-1 praziquantel each at an interval of four days. Seven days after the first treatment, the mucus surface of the fish was re-examined, which did not reveal the parasites presence being delivered for commercialization.

O objetivo deste trabalho foi avaliar as variáveis hematológicas e a condição corporal e higidez de tuviras, Gymnotus spp. sob condições de cultivo. Foram utilizados 42 peixes com peso médio de 42,9 ± 31,8 (g) e comprimento médio de 23,7 ± 3,3 (cm) oriundos de diferentes isqueiros. Procedeu-se anestesia com óleo de cravo, seguida de colheita de sangue dos animais por venopunção caudal, de cada peixe foi colhido 1,5 mL-1, de sangue aproximadamente. Determinou-se a concentração de eritrócitos, percentual de hematócrito, taxa de hemoglobina, o volume corpuscular médio (VCM), a concentração de hemoglobina corpuscular média (CHCM) e o fator de condição (Kn). Os resultados mostraram que o valor de eritrograma variou de 0,880 a 3,940 x 106µl-1, o valor percentual de hematócrito variou de 20,0 a 51,5%, a taxa de hemoglobina de 4,4 a 14,9 g dL-1, o VCM 121,8 a 250,0fL-1 , o CHCM de 15,0 a 35,6 g dL-1, e o Kn= 1,00 ± 0,041. Os valores hematológicos de Gymnotus spp, obtidos encontram-se dentro das características apresentadas por outras espécies criadas em sistemas de cultivo. Os dados avaliados neste trabalho demonstraram que as tuviras mantidas nos isqueiros apresentaram boas condições corporais e higidez.

The present study evaluated the dietary supplementation with essential oil of Lippia alba on the hemato-immunological parameters of Nile tilapia (Oreochromis niloticus) submitted to acute inflammation induced by carrageenin injection in the swim bladder. For a period of 45 days, 96 fish were divided in four treatments in triplicate, as follows: fish fed supplemented diet with essential oil of L. alba (4 mL kg-1 dry ration) injected with carrageenin; fish fed supplemented diet with cereal alcohol injected with carrageenin; fish fed unsupplemented diet with essential oil injected with carrageenin; fish fed unsupplemented diet and noninjected. Cortisol levels, erythrogram, leukogram and the inflammatory infiltrate were analyzed 6 h after inflammatory stimulus. Carrageenin-injected fish showed acute inflammatory reaction in the swim bladder characterized by higher infiltrate of neutrophils and monocytes. The circulating neutrophils number was significantly higher in fish fed L. alba when compared to other treatments. No difference in cortisol levels was found. For dose, time and administration form tested, supplementation with essential oil of L. alba did not present anti-inflammatory activity. On the other hand, influence of dietary supplementation was observed on the neutrophils number after induced aerocystitis highlighting its immunomodulatory characteristic.

This study registers for the first time the copepod Acusicola sp. infesting the gills of farmed yellowtail tetra Astyanax altiparanae, as well as new information on gross pathology and gill alterations. Five specimens of yellowtail tetra showing slow swimming, respiratory difficulty, scaleness and darkened skin were examined. Fish were analysed in situ for ectoparasites diagnosis. Fragments of the gill arches were removed and processed according to usual histopathology. The gills showed focal and multifocal paleness and whitish areas besides the congestion and hemorrhage signs on the gill filaments. Several white spots attached to the gill filament apex with slight movement were identified as the ergasilid crustacean. Histopathological analysis revealed the gill and blood vessels compression. It was also observed proliferative alterations close to gill filament apex, hyperplasia, total fusion and subepithelial oedema of the secondary lamellae, proliferation of the mucus cells, and inflammatory infiltrate by eosinophilic granular cells surrounding the parasite attachment region. The best management practices and the implementation of diagnostic program are also discussed.

This study evaluated the haematological parameters of the hybrid surubim (Pseudoplatystoma corruscans x P. reticulatum) farmed in intensive and semi intensive system. A total of 240 fish were examined, 120 from fish farm and 120 from a semi-intensive for comparison between the hot and cold season. The water quality was weekly measured to evaluate the influence of environmental conditions on the haematology. Fish from intensive system showed hematocrit and white blood cell count (WBC) higher in hot season while the total plasmatic protein, hemoglobin concentration, mean corpuscular hemoglobin concentration (MCHC) and mean corpuscular volume (MCV) were higher in cold season. In fish from semi intensive system, the red blood cells count (RBC) and total thrombocyte number was higher in hot season while the MCHC and MCV were higher in cold season. There was no alterations in the numbers of lymphocytes, neutrophils, basophils, eosinophils and PAS - positive granular leukocyte (PAS-LG). The results showed the influence of seasonality on the hematological parameters of the hybrid surubim kept under normal farming conditions. Regarding water quality, hot season was directly related to increased water temperature and decreased dissolved oxygen while the opposite was found in cold season.

ABSTRACT: Fish in both natural and farming conditions are exposed to stress of capture, handling, transport or treatment that provoke low zootechnical performance. Anesthetics like eugenol obtained from clove oil have been used strategically not only in freshwater but also in marine and estuarine fish in order to reduce the stress. Apart from the eugenol indication as anesthetic and its low toxicity for animals, its environment action is not clear. Bioassays or ecotoxicity tests with indicator organisms are used to evaluate the mode of action of the pollutants in the environment. The aim of this study was to test the acute toxicity of eugenol using the microcrustacean Daphnia magna and the bacterium Aliivibrio fischeri, and also its chronic toxicity for the algae Desmodesmus subspicatus. Eugenol in the concentrations of 50, 75 and 100mg L-1 were toxic to tested indicator organisms.

ABSTRACT: Ichthyophthiriasis is a worldwide fish disease with great financial impact on freshwater fish farming due to its associated high mortality rates. Current study assesses the parasiticidal capacity of hydrogen peroxide (H2O2) and chlorine dioxide (ClO2) against the causative agent, Ichthyophthirius multifiliis, in jundiá. Median lethal concentration (LC50, 96h) of each chemical agent was established, as well as the minimum inhibitory concentration of hydrogen peroxide for the parasite´s infectious larval phase (theront). Products were tested asynchronously in parasitized fingerlings for short and long baths at the following concentrations and exposure times: 1. Hydrogen peroxide: (T1) continuous bath - 30ppm and (T2) 50ppm; (T3) short bath - 150ppm, during 1h and (T4) 250ppm during 1h; control group (without any chemical agent). 2. Chlorine dioxide: (T1) continuous bath - 4ppm and (T2) 20ppm; (T3) short bath - 200ppm, during 1min; (T4) short bath - 400ppm, during 1min and control group. Data analysis demonstrated a concentration of 82.54ppm of the commercial product (or 24.76ppm of the active chemical agent) as LC50, 96h of H2O2 and 38.4ppm product (or 2.68ppm of the active chemical agent) for ClO2. Hydrogen peroxide concentration causing 100% mortality rate of theronts in 1h was 25ppm (product, or 7.5ppm of the active chemical agent). At the end of the fourth day of curative experiment, 98% of the animals died by ichthyophthiriasis. No treatment was effective against the parasite.

The objective of this study was to investigate the influence of dietary supplementation with propolis on hematology and number and area of melanomacrophage centers in spleen and kidney of tilapia. After acclimation, fish (24.7 ± 7.4 gmean weight) were distributed in 6 tanks 100 L, 6 fish per tank, in triplicate, at a temperature 24.0 ± 2.8oC, with two treatments: Fish fed 2% propolis supplemented diet and fish fed non-supplemented diet. To monitor the evolution of the effects, two samples were collected: half of the fish from each treatment were used after 15 days and the other half after 21, composing two feeding times. After each feeding time, blood, spleen and kidney were collected. After twenty one days feeding on 2% propolis supplemented diet, fish showed a lower number of total leukocytes and lymphocytes and an increase in the total erythrocytes number. Fish fed supplemented diet presented an increased number of melanomacrophage centers. We observed hemosiderin in all spleen samples. Kidney showed no significant difference on the presence of melanomacrophage centers containing hemosiderin. Despite these changes, the fish health status was not affected. The results showed that propolis supplementation in the diet ofNile tilapia may be physiologically feasible.

The current study presents a parasitological survey of larval nematodes from freshwater ornamental fish Iguanodectes spilurus caught in the watercourse of the Caete River, in the northeast region of the State of Para, Brazil. A total of 176 specimens, 1.36±0.75 g weight and 5.53±0.98 cm total length, were analyzed. Nematode larvae were identified as Capillaria sp., Procamallanus sp. and Anisakidae, with prevalence of 70.45% and infection intensity ranging from 1.81 to 4.70 larvae. The highest prevalence 57.38% occurred in the liver, but no seasonality was observed, indicating high infection throughout the year. Seasonality was observed in fish parasitized in the stomach, intestine and caecum, with prevalence and mean intensity of 17.61% and 2.32 parasites, 12.5% and 1.81 parasites, 10.79% and 2.21 parasites, respectively. The highest degree of infection was observed in the rainy season, probably due to increased availability of intermediate hosts or food.

Tissues fixed and embedded in paraffin for histopathological studies keep their cell characteristics. There are several protocols for extracting genetic material from tissue embedded in paraffin, but there is no protocol for material aimed at the direct identification of parasites. The lack of techniques which describe the recovery of parasites from tissue embedded in paraffin has led us to test a technique for recovering myxosporean parasites found in Piaractus mesopotamicus kidney fragments embedded in paraffin, for a rapid, direct, and economic identification. Once the excess paraffin was removed from the kidney fragment, this was deparaffinized in xylene, hydrated in 70% alcohol, placed in an Eppendorf tube containing 70% alcohol, and left under vigorous and constant agitation in a vortex until the tissue was disintegrated. The precipitated material was mixed with the 70% alcohol and 20 µL were collected for preparing the smears, which were stained with Giemsa. Myxobolus sp. spores at many developmental stages were observed by light microscopy. The technique has proved to be useful for recovering myxosporean parasites from tissue embedded in paraffin and it constitutes an effective tool for prevalence studies when the myxosporean parasites are not detected in fresh mounts.

The objective of this work was to isolate strains of lactic acid bacteria with probiotic potential from the digestive tract of marine shrimp (Litopenaeus vannamei), and to carry out in vitro selection based on multiple characters. The ideotype (ideal proposed strain) was defined by the highest averages for the traits maximum growth velocity, final count of viable cells, and inhibition halo against nine freshwater and marine pathogens, and by the lowest averages for the traits duplication time and resistance of strains to NaCl (1.5 and 3%), pH (6, 8, and 9), and biliary salts (5%). Mahalanobis distance (D²) was estimated among the evaluated strains, and the best ones were those with the shortest distances to the ideotype. Ten bacterial strains were isolated and biochemically identified as Lactobacillus plantarum (3), L. brevis (3), Weissella confusa (2), Lactococcus lactis (1), and L. delbrueckii (1). Lactobacillus plantarum strains showed a wide spectrum of action and the largest inhibition halos against pathogens, both Gram-positive and negative, high growth rate, and tolerance to all evaluated parameters. In relation to ideotype, L. plantarum showed the lowest Mahalanobis (D²) distance, followed by the strains of W. confusa, L. brevis, L. lactis, and L. delbrueckii. Among the analyzed bacterial strains, those of Lactobacillus plantarum have the greatest potential for use as a probiotic for marine shrimp.

O objetivo deste trabalho foi avaliar a resposta hematológica e parasitológica de tambacus (Colossoma macropomum x Piaractus mesopotamicus) submetidos ao estresse de captura e a diferentes densidades de estocagem, em sistema de pesque-solte. Foram utilizados 210 peixes com peso médio inicial de 785,33±152,02 g e comprimento total médio de 34,43±2,21 cm, mantidos em viveiros escavados e divididos em três grupos: sem pesca e baixa densidade (G1), com pesca e baixa densidade (G2), e com pesca e alta densidade (G3). Não houve diferença significativa entre os valores médios da concentração de hemoglobina, do número de eritrócitos, da contagem diferencial de leucócitos e da glicose. Os peixes do grupo G3 apresentaram número maior de parasitos e trombócitos, e menor ganho de peso e hematócrito. A atividade de pesque-solte, aliada à alta densidade de estocagem, pode prejudicar o equilíbrio orgânico e o desempenho zootécnico, o que favorece a parasitose.

O objetivo deste trabalho foi avaliar a fauna parasitária dos peixes híbridos cachapinta (Pseudoplatystoma corruscans macho x P. reticulatum fêmea) e jundiara (Leiarius marmoratus macho x P. reticulatum fêmea) no período de larvicultura. Um total de 315 animais, 126 híbridos jundiara e 189 híbridos cachapinta, foram examinados de acordo com o estágio de desenvolvimento: larvas, pós-larvas e alevinos. Larvas e pós-larvas foram prensadas entre lâmina e lamínula e observadas sob microscopia óptica. Os alevinos foram observados externamente em estereomicroscópio e necropsiados para avaliação interna dos órgãos. Foram aferidos os parâmetros de qualidade de água em todas as fases de cultivo. O exame parasitológico revelou a presença dos protozoários Epistylis sp. e Trichodina sp., no tegumento e nas brânquias, Ichthyophthirius multifiliis no tegumento, dos helmintos Monogenea nas brânquias, e das metacercárias de digenéticos em brânquias, baço, rins, fígado e intestino, em ambos os híbridos analisados. Os parasitos Epystilis sp., Trichodina sp. e metacercária de digenéticos ocorrem com maior frequência nos dois híbridos, nas fases de pós-larvas e alevinos. Há maior prevalência e diversidade de parasitos na fase de alevinagem dos híbridos estudados.

The present work morphologically characterizes Paratrichodina africana from the gills of wild and farmed Nile tilapia from Northern Brazil (eastern Amazonia). Ninety fish were captured for parasitological analysis in Macapá, State of Amapá, from a wetland area bathed by the Amazon River commonly called ‘Ressaca do Zerão’ (n = 52), as well as from a local fish farm (n = 38). Wet smears of the skin and gills of the captured fish were air dried at room temperature and impregnated with silver nitrate by Klein's method for posterior examination of the adhesive disc structures. Total prevalence of parasitism was 16.6% (23% in fish from wetland and 7.8% in farmed fish). Characterized as a small-sized trichodinid, it presented the following measures: 33.2 ± 4.7 µm body diameter, 17.5 ± 2.1 µm adhesive disc, 10.0 ± 0.9 µm denticulate ring, and 22.6 ± 2.0 denticles. Paratrichodina africana reported in this study strongly resembles those described for other localities, but it differs by presenting greater body length. This is the fourth report of P. africana parasitizing a host fish.

Family Trichodinidae comprises ciliate protozoa distributed worldwide; they are considered some of the main parasitological agents infecting cultivated fish. However, the trichodinidae parasitizing important fish species cultured in Brazil are unknown, and more taxonomic studies on this group of parasites are required. This research morphologically characterizes Trichodina colisae Asmat & Sultana, (2005) of pacu (Piaractus mesopotamicus) and patinga hybrid (P. mesopotamicus × P. brachypomus) cultivated in the central and southeast regions of the country. Fresh assemblies were made from mucus scraped from the skin, fins and gills, fixed with methanol and, subsequently, impregnated with silver nitrate and stained with Giemsa for assessment under light microscopy. This research reports not only the second occurrence of T. colisae in the world, but also its first occurrence in South America.Tricodinídeos são protozoários ciliados móveis com ampla distribuição mundial; são considerados um dos agentes parasitários que mais acometem peixes cultivados. No Brasil, a maioria dos tricodinídeos que parasitam importantes espécies de peixes cultivados são desconhecidos, o que requer mais estudos taxonômicos com esse grupo de parasitos. Este estudo caracteriza morfologicamente Trichodina colisae Asmat & Sultana, 2005 de pacu (Piaractus mesopotamicus) e do híbrido patinga (P. mesopotamicus × P. brachypomus) cultivados, respectivamente, no Centro-Oeste e Sudeste do Brasil. Foram feitas montagens a fresco do raspado de muco da pele, nadadeiras e brânquias, fixados com metanol e, posteriormente, impregnados com nitrato de prata e coradas com Giemsa para avaliação em microscopia óptica. O presente estudo relata não só a segunda ocorrência de T. colisae no mundo, mas também a primeira ocorrência na América do Sul.

This study characterized morphologically Trichodina heterodentata Duncan, 1977 from cultivated fingerlings of "pirarucu" Arapaima gigas in Peru. Body and gill smears were air-dried at room temperature, impregnated with silver nitrate and/or stained with gomori trichromic. Prevalence was 100%. Trichodina heterodentata was considered a medium-sized trichodinid with mean body diameter of 56.0+ 5.25 (47.3-76.0) μm, denticulate ring 28.21± 2.71 (20-34.7) μm, adhesive disc 45.7±3.8 (37.1-57.3) μm diameter and number of denticles of 20.7± 2.6 (12-24). The present study reports not only the first occurrence of T. heterodentata in Peru but also the first record of this trichodinid infesting A. gigas. Camparative tables of all reports of T. heterodentata are also presented.Este estudo caracterizou morfologicamente Trichodina heterodentata Duncan, 1977 de alevinos de "pirarucu" Arapaima gigas cultivados no Peru. Esfregaços do corpo e brânquias foram secos à temperatura ambiente, impregnados com nitrato de prata e/ou corados com tricrômico de gômori. A prevalência foi de 100%. Trichodina heterodentata foi considerada um tricodinídeo de tamanho médio com diâmetro médio do corpo de 56,0+ 5,25 (47,3-76,0) μm, anel denticulado 28,21± 2,71 (20,0-34,7) μm, disco adesivo 45,7±3,8 (37,1-57,3) μm de diâmetro e número de dentículos de 20,7± 2,6 (12-24). O presente estudo registra não somente a primeira ocorrência de T. heterodentata no Peru mas também o primeiro registro do tricodinídeo parasitando A. gigas. Tabelas comparativas biométricas de todos os registros de T. heterodentata também são apresentados.

An occurrence of the copepod Lamproglena monodi Capart, 1944, parasitizing freshwater fishes in Brazil is presented, along with new morphological data. This crustacean was originally described parasitizing several cichlids in Africa. In the present study, the crustaceans were collected from the body surface and gills of two fish species native to Brazil [Astronotus ocellatus (Agassiz, 1831) and Cichla ocellaris Bloch and Schneider, 1801] and two introduced species [Oreochromis niloticus (Linnaeus, 1758) and Tilapia rendalli (Boulenger, 1897)]. The Brazilian specimens exhibited some morphometric intraspecies differences in relation to the specimens from Congo-Kinshasa and Egypt.A ocorrência e novos dados morfológicos do copépode Lamproglena monodi Capart, 1944 parasitando peixes dulcícolas no Brasil são apresentados. Este crustáceo foi originalmente descrito parasitando vários ciclídeos da África. No presente trabalho, os crustáceos foram coletados das brânquias e superfície do corpo dos peixes nativos do Brasil [Astronotus ocellatus (Agassiz, 1831) e Cichla ocellaris Bloch e Schneider, 1801 e duas espécies introduzidas Oreochromis niloticus (Linnaeus, 1758) e Tilapia rendalli (Boulenger, 1897)]. Os espécimes coletados no Brasil apresentaram algumas diferenças morfométricas intraespecíficas em relação aos espécimes do Congo-Kinshasa e Egito.

The objective of this work was to evaluate the effect of food supplementation with vitamin C on macrophage and multinucleated giant cell (MGC) activities of pacus at two stocking densities. The experiment was carried out in a 2x2x3 split-plot factorial arrangement with: 0 and 500 mg kg-1 vitamin C; 5 and 20 kg m-3 stocking densities; and evaluation times at 3, 6, and 12 days after the subcutaneous implantation of glass coverslips (DPI). The number of macrophages and MGC, as well as cortisol and glucose plasma levels were determined. The number of macrophages and MGC with two to five nuclei was significantly greater in fish supplemented with vitamin C at 5 kg m-3 stocking density at 3 DPI in comparison to nonsupplemented ones. The macrophage and MGC counts were lower in fish with high-plasma cortisol concentration. Supplementation with 500 mg vitamin C benefits macrophage activity on foreign-body inflammation, and high-cortisol concentration has suppressive effects on this response.

Parasitological indexes of Austrodiplostomum compactum (Digenea, Diplostomidae) in fishes from the Paraná River, Presidente Epitácio region, state of São Paulo, Brazil, and their relationship with climate and water quality are evaluated. Fifty-one specimens of Plagioscion squamosissimus, 39 Geophagus surinamensis, 27 Hoplias malabaricus and 23 Cichla sp. were collected between June 2007 and June 2008. Water quality and rainfall indexes were measured monthly. P. squamosissimus had the highest parasite rate, with 98% total prevalence, intensity of infection varying between 1 and 255 and parasite mean abundance totaling 40.5 ± 9.9. H. malabaricus had the next parasite rate, with 66.6% total prevalence, parasite intensity between 2 and 184 and mean abundance totaling 22.4  20.9. Cichla sp. had a total prevalence of 52.1%, intensity between 1 and 21, and mean abundance 4.3 ± 2.9. Finally, G. surinamensis had a total prevalence of 46.1%, intensity between 1 and 53 and mean abundance 7.1  8.8. A survey of diplostomid infection in Brazil and the role of piscivore fish as an important host have also been discussed.Este estudo avaliou os índices parasitológicos de Austrodiplostomum compactum (Digenea, Diplostomidae) em peixes do rio Paraná, região de Presidente Epitácio, Estado de São Paulo, Brasil e sua relação com o clima e qualidade da água. Cinquenta e um espécimes de Plagioscion squamosissimus, 39 Geophagus surinamensis, 27 Hoplias malabaricus e 23 Cichla sp. foram coletados de junho de 2007 a junho de 2008. Qualidade da água e pluviosidade foram medidas mensalmente. O peixe mais parasitado foi P. squamosissimus com 98% de prevalência total, intensidade de infecção variando de 1 a 255 e abundância média de 40,5 ± 9,9. O segundo peixe mais parasitado foi H. malabaricus com 66,6% de prevalência total, intensidade de 2 a 184 e abundância média de 22,4 ± 20,9. Cichla sp. apresentou 52,1% de prevalência, intensidade de 1 a 21 e abundância média de 4,3 ± 2,9. Finalmente, G. surinamensis apresentou 46,1% de prevalência, intensidade de 1 a 53 e abundância média de 7,1 ± 8,8. Um levantamento de infecções por diplostomídeos no Brasil e o papel de peixes piscívoros como importantes hospedeiros é também discutido.

Parasitological indexes of Austrodiplostomum compactum (Digenea, Diplostomidae) in fishes from the Paraná River, Presidente Epitácio region, state of São Paulo, Brazil, and their relationship with climate and water quality are evaluated. Fifty-one specimens of Plagioscion squamosissimus, 39 Geophagus surinamensis, 27 Hoplias malabaricus and 23 Cichla sp. were collected between June 2007 and June 2008. Water quality and rainfall indexes were measured monthly. P. squamosissimus had the highest parasite rate, with 98% total prevalence, intensity of infection varying between 1 and 255 and parasite mean abundance totaling 40.5 ± 9.9. H. malabaricus had the next parasite rate, with 66.6% total prevalence, parasite intensity between 2 and 184 and mean abundance totaling 22.4 ± 20.9. Cichla sp. had a total prevalence of 52.1%, intensity between 1 and 21, and mean abundance 4.3 ± 2.9. Finally, G. surinamensis had a total prevalence of 46.1%, intensity between 1 and 53 and mean abundance 7.1 ± 8.8. A survey of diplostomid infection in Brazil and the role of piscivore fish as an important host have also been discussed.

The present study evaluated the acute inflammatory response induced bycarrageenin (500 £gg) injected in the swim bladder of Nile tilapia, after fed or not probiotic supplemented diet. Fifty four fish were distributed in six treatments and three replicates: Group A: Fish fed unsupplemented diet: 0.5 mL saline-injected fish; fish injected with 500 £gg carrageenin diluted in 0.5 mL saline; Non-injected. Group B: Fish fed probiotic supplemented diet: saline-injected fish; carrageenin-injected fish; Non-injected. Fifteen days after feeding the fish were injected with carrageenin or saline. After six hours, inflammatory exudate was collected, as well as the blood for hematocrit, red blood cell (RBC) and white blood cell (WBC) counts, differential count of leucocytes and phagocytic activity in the blood. Supplementation with probiotic did not influence the RBC, hematocrit and the numbers of lymphocytes and basophils in the blood. The number of neutrophils was significantly higher in supplemented fish injected with carrageenin. Glucose concentration in supplemented and non-injected fish was higher than that observed in the saline injected ones. Probiotic potentialized the migration of cells to the inflammatory focus in the animals injected with the carrageenin irritant. In fish injected with saline and carrageenin occurred the greatest phagocytic activity in the blood in relation to those treatments.Este trabalho avaliou a resposta inflamatoria aguda induzida por injecao de carragenina (500 ƒÝg) na bexiga natatoria de tilapia do Nilo suplementada ou nao com probiotico na racao. Cinquenta e quatro animais foram distribuidos em seis tratamentos com tres repeticoes: Grupo A: peixes alimentados com racao naosuplementada: Controle (injecao de 0,5 mL de solucao salina esteril); Carragenina (injecao de500 £gg de carragenina); Nao-injetada. Grupo B: peixes alimentados com racao suplementada com probiotico: Controle; Carragenina; Nao-injetada. Apos 15 dias de alimentacao foi injetado carragenina ou salina. Apos 6h, realizou-se a coleta de exsudato e sangue para determinacao do hematocrito, contagens totais de eritrocitos, leucocitos, contagem diferencial de leucocitos e atividade fagocitaria no sangue. A suplementacao com probiotico na racao nao influenciou o numero total de eritrocitos, o hematocrito e os numeros de linfocitos e basofilos no sangue dos animais. O numero de neutrofilos foi maior nos peixes suplementados com probiotico einjetados com carragenina. A glicose nos peixes suplementados com probiotico nao-injetados foi maior do que nos injetados com salina. A suplementacao com probiotico potencializou a migracao de celulas para o foco inflamatorio nos injetados com o flogogeno carragenina. Empeixes injetados com salina e carragenina, ocorreu maior atividade fagocitaria no sangue em relacao aos demais tratamentos.

This study evaluated the parasitism by Anacanthorus penilabiatus (Monogenoidea) and Piscinoodinium pillulare (Dinoflagellida) in the gills of "pacu", Piaractus mesopotamicus supplemented with chromium in the diet. Randomised delineation by using factorial scheme (4x2x2) for Monogenoidea and 4x2x3 for Dinoflagellate with four levels of chromium (0, 6, 12, 18mg/kg diet), two stocking densities (4kg/m³ and 20kg/m ³), two classes of length (higher and lower than 17 cm) for a period of 7, 60 and 90 days, and four replicates was used. The fishes in low density which received 12 and 18mg/kg showed decreased monogeneoidea values, seven days after the experiment begin. Six, 12 and 18 mg/kg caused reduction in the dinoflagellate number in the fishes maintained at 20kg/m³. It was possible that chromium supplementation (12 e 18mg/kg) favoured the fishes health by reducing Monogenoidea and Dinoflagellida number in lower and higher densities, respectively.O objetivo do trabalho foi avaliar a intensidade de parasitismo por monogenóide Anacanthorus penilabiatus e pelo dinoflagelado Piscinoodinium pillulare em pacus Piaractus mesopotamicus, cuja dieta foi suplementada com cromo. Foram utilizados dois delineamentos em esquema fatorial, consistindo de 4 níveis de cromo (0, 6, 12, 18 mgCQC/kg), duas densidades de estocagem (4 kg/m³ e 20 kg/m³) e duas classes de tamanho para monogenóide (maiores e menores de 17cm) e/ou 3 períodos de coleta (7, 60 e 90 dias), com quatro repetições. Os peixes que receberam 12 e 18mg CQC/kg apresentaram diminuição de monogenóides após 7 dias de alimentação na menor densidade. Nos peixes na maior densidade, os níveis de 6, 12 e 18 mgCQC/kg ocasionou redução de dinoflagelados. Os resultados demonstraram que a suplementação com cromo (12 e 18 mgCQC/kg) promoveu uma melhora na saúde dos peixes na menor e na maior densidade, respectivamente.