Glomerulocystic kidney in two red piranhas Pygocentrus nattereri.

Glomerulocystic kidney (GCK) is defined by a dilatation of the Bowman's space (greater than 2 times the normal size) of more than 5% of all glomeruli. Although GCK has been occasionally documented in dogs, cats, and humans with renal failure, in fish, reports of spontaneous GCK are rare. For the present study, 2 captive adult red piranhas Pygocentrus nattereri from a closed population were submitted for post-mortem examination. Clinical history included lethargy, inappetence, dyspnea, and altered buoyancy. Macroscopically, the fish displayed coelomic distension and ascites. The kidneys were markedly enlarged and dark yellow. Histologically, Bowman's space was noticeably dilated, occasionally with atrophic glomerular tufts. Degeneration and necrosis of the tubular epithelium, infiltration, and nephrocalcinosis were also present. To the authors' knowledge, this present study is the first report of spontaneously occurring GCK in red piranhas and freshwater fish in general. Despite being rare, GCK is a condition with the potential to impair the health of fish and mammals, and further studies are needed to shed new light on this condition.

Piranha-etched titanium nanostructure reduces biofilm formation in vitro.

OBJECTIVES: Nano-modified surfaces for dental implants may improve gingival fibroblast adhesion and antibacterial characteristics through cell-surface interactions. The present study investigated how a nanocavity titanium surface impacts the viability and adhesion of human gingival fibroblasts (HGF-1) and compared its response to Porphyromonas gingivalis with those of marketed implant surfaces. MATERIAL AND METHODS: Commercial titanium and zirconia disks, namely, sandblasted and acid-etched titanium (SLA), sandblasted and acid-etched zirconia (ZLA), polished titanium (PT) and polished zirconia (ZrP), and nanostructured disks (NTDs) were tested. Polished titanium disks were etched with a 1:1 combination of 98% H2SO4 and 30% H2O2 (piranha etching) for 5 h at room temperature to produce the NTDs. Atomic force microscopy was used to measure the surface topography, roughness, adhesion force, and work of adhesion. MTT assays and immunofluorescence staining were used to examine cell viability and adhesion after incubation of HGF-1 cells on the disk surfaces. After incubation with P. gingivalis, conventional culture, live/dead staining, and SEM were used to determine the antibacterial properties of NTD, SLA, ZLA, PT, and ZrP. RESULTS: Etching created nanocavities with 10-20-nm edge-to-edge diameters. Chemical etching increased the average surface roughness and decreased the surface adherence, while polishing and flattening of ZrP increased adhesion. However, only the NTDs inhibited biofilm formation and bacterial adherence. The NTDs showed antibacterial effects and P. gingivalis vitality reductions. The HGF-1 cells demonstrated greater viability on the NTDs compared to the controls. CONCLUSION: Nanocavities with 10-20-nm edge-to-edge diameters on titanium disks hindered P. gingivalis adhesion and supported the adhesion of gingival fibroblasts when compared to the surfaces of currently marketed titanium or zirconia dental implants. CLINICAL RELEVANCE: This study prepared an effective antibacterial nanoporous surface, assessed its effects against oral pathogens, and demonstrated that surface characteristics on a nanoscale level influenced oral pathogens and gingival fibroblasts. CLINICAL TRIAL REGISTRATION: not applicable.

Red piranha optimization (RPO): a natural inspired meta-heuristic algorithm for solving complex optimization problems.

An optimization algorithm is a step-by-step procedure which aims to achieve an optimum value (maximum or minimum) of an objective function. Several natural inspired meta-heuristic algorithms have been inspired to solve complex optimization problems by utilizing the potential advantages of swarm intelligence. In this paper, a new nature-inspired optimization algorithm which mimics the social hunting behavior of Red Piranha is developed, which is called Red Piranha Optimization (RPO). Although the piranha fish is famous for its extreme ferocity and thirst for blood, it sets the best examples of cooperation and organized teamwork, especially in the case of hunting or saving their eggs. The proposed RPO is established through three sequential phases, namely; (i) searching for a prey, (ii) encircling the prey, and (iii) attacking the prey. A mathematical model is provided for each phase of the proposed algorithm. RPO has salient properties such as; (i) it is very simple and easy to implement, (ii) it has a perfect ability to bypass local optima, and (iii) it can be employed for solving complex optimization problems covering different disciplines. To ensure the efficiency of the proposed RPO, it has been applied in feature selection, which is one of the important steps in solving the classification problem. Hence, recent bio-inspired optimization algorithms as well as the proposed RPO have been employed for selecting the most important features for diagnosing Covid-19. Experimental results have proven the effectiveness of the proposed RPO as it outperforms the recent bio-inspired optimization techniques according to accuracy, execution time, micro average precision, micro average recall, macro average precision, macro average recall, and f-measure calculations.

Piranha solution treatment: A facile method for improving the antithrombotic ability and regulating smooth muscle cell growth on blood contact materials.

Blood contact materials require strong anti-fouling capabilities to avoid thrombus formation. Recently, TiO2-based photocatalytic antithrombotic treatment has gained focus. Nevertheless, this method is restricted to titanium materials with photocatalytic abilities. This study offers an alternative solution that can be applied to a broader range of materials: piranha solution treatment. Our findings revealed that the free radicals generated by the treatment effectively altered the surface physicochemical properties of various inorganic materials, enhancing their surface hydrophilicity and oxidizing organic contaminants, thus improving their antithrombotic properties. Additionally, the treatment resulted in contrasting effects on the cellular affinity of SS and TiO2. While it significantly reduced the adhesion and proliferation of SMCs on SS surfaces, it significantly enhanced these on TiO2 surfaces. These observations suggested that the impact of the piranha solution treatment on the cellular affinity of biomaterials was closely tied to the intrinsic properties of the materials. Thus, materials suitable for piranha solution treatment could be selected based on the functional requirements of implantable medical devices. In conclusion, the broad applicability of piranha solution surface modification technology in both blood-contact and bone implant materials highlights its promising prospects.

Evaluation of a nitinol stone retrieval basket as an alternative to biopsy forceps for biopsy of suspected upper tract genitourinary malignancies.

Background: The anatomical nature of the ureteroscopic approach for biopsy of upper urothelial tract tumors requires the utilization of small instruments, often limiting biopsy specimen quality. This leads to lower-than-desired tumor grading accuracy and malignancy detection capabilities on the initial evaluation of upper tract tumor specimens. This is problematic because optimal treatment of upper tract urothelial carcinoma (UTUC) depends on early disease detection and subsequent accurate diagnosis. Objective: The objective of our study was to compare the biopsy capabilities of two ureteroscopic biopsy instruments - biopsy forceps and the nitinol stone retrieval basket. Methods: We performed a retrospective analysis of ten patients who underwent biopsy of an upper tract mass with either instrument. Average specimen size, muscularis propria presence, and malignancy detection sensitivity were the variables of interest. Results: The nitinol stone retrieval basket obtained larger biopsy samples than the biopsy forceps, with average biopsy volumes being 0.0674 cm3 and 0.0075 cm3, respectively (P = 0.00017); this was the only statistically significant result of our study. Muscularis propria was present in 31% (4/13) of the biopsies with the nitinol stone retrieval basket, whereas 0% (0/5) of the biopsy forceps biopsies contained muscularis propria (P = 0.2778). Regarding malignancy detection sensitivity, the nitinol stone retrieval basket biopsies identified malignancy in 100% of the specimens that had confirmed malignancy; the biopsy forceps only detected malignancy 40% of the time (P = 0.4134). Conclusion: These findings suggest that the nitinol stone retrieval basket is a useful diagnostic tool for UTUC, although further investigation is warranted to determine its superiority compared to biopsy forceps.

The record and threats of the invasion of palometa Serrasalmus maculatus (Characiformes: Serrasalmidae) in the Patos lagoon drainage, southern Brazil.

We report the occurrence of an invasive alien species, palometa Serrasalmus maculatus, in the Patos Lagoon drainage. Primary occurrence data were based on three specimens captured and preserved as vouchers in scientific collections. Additionally, we searched for secondary records from unpublished scientific sources, public agencies reports and media news to find additional reports. We discussed the possible pathways of invasion, suggesting as the vector of introduction transpositions from the Uruguay River basin. Ecological implications for ichthyofauna, environmental impacts and risk of other events of invasion in the adjoining basins are discussed.

Cenospheres-Reinforced PA-12 Composite: Preparation, Physicochemical Properties, and Soaking Tests.

The main aim of this research was the preparation of a polymer-ceramic composite with PA-12 as the polymer matrix and modified aluminosilicate cenospheres (CSs) as the ceramic filler. The CSs were subjected to an early purification and cleaning process, which was also taken as a second objective. The CSs were surface modified by a two-step process: (1) etching in Piranha solution and (2) silanization in 3-aminopropyltriethoxysilane. The composite was made for 3D printing by FDM. Raw and modified CSs and a composite with PA-12 were subjected to the following tests: surface development including pores (BET), real density (HP), chemical composition and morphology (SEM/EDS, FTIR), grain analysis (PSD), phase composition (XRD), hardness (HV), and static tensile tests. The composites were subjected to soaking under simulated body fluid (SBF) conditions in artificial saliva for 14, 21, and 29 days. Compared to pure PA-12, PA-12_CS had generally better mechanical properties and was more resistant to SBF at elevated temperatures and soaking times. These results showed this material has potential for use in biomedical applications. These results also showed the necessity of developing a kinetic aging model for aging in different liquids to verify the true value of this material.

Development and Assessment of Regeneration Methods for Peptide-Based QCM Biosensors in VOCs Analysis Applications.

Cleaning a quartz crystal microbalance (QCM) plays a crucial role in the regeneration of its biosensors for reuse. Imprecise removal of a receptor layer from a transducer's surface can lead to unsteady operation during measurements. This article compares three approaches to regeneration of the piezoelectric transducers using the electrochemical, oxygen plasma and Piranha solution methods. Optimization of the cleaning method allowed for evaluation of the influence of cleaning on the surface of regenerated biosensors. The effectiveness of cleaning the QCM transducers with a receptor layer in the form of a peptide with the KLLFDSLTDLKKKMSEC-NH2 sequence was described. Preliminary cleaning was tested for new electrodes to check the potential impact of the cleaning on deposition and the transducer's operation parameters. The effectiveness of the cleaning was assessed via the measurement of a resonant frequency of the QCM transducers. Based on changes in the resonant frequency and the Sauerbrey equation, it was possible to evaluate the changes in mass adsorption on the transducer's surface. Moreover, the morphology of the QCM transducer's surface subjected to the selected cleaning techniques was presented with AFM imaging. The presented results confirm that each method is suitable for peptide-based biosensors cleaning. However, the most invasive seems to be the Piranha method, with the greatest decrease in performance after regeneration cycles (25% after three cycles). The presented techniques were evaluated for their efficiency with respect to a selected volatile compound, which in the future should allow reuse of the biosensors in particular applications, contributing to cost reduction and extension of the sensors' lifetime.

Use of Piranha Solution as An Alternative Route to Promote Bioactivation of PEEK Surface with Low Functionalization Times.

This study aimed to achieve bioactivity on the PEEK surface using piranha solution through a lower functionalization time. For this purpose, the functionalization occurred with piranha solution and 98% sulfuric acid in the proportions of 1:2, 1:1, and 2:1 at periods of 30, 60, and 90 s. The samples treated for longer times at higher concentrations registered the characteristic spectroscopy band associated with sulfonation. Additionally, both chemical treatments allowed the opening of the aromatic ring, increasing the number of functional groups available and making the surface more hydrophilic. The piranha solution treatments with higher concentrations and longer times promoted greater heterogeneity in the surface pores, which affected the roughness of untreated PEEK. Furthermore, the treatments induced calcium deposition on the surface during immersion in SBF fluid. In conclusion, the proposed chemical modifications using sulfuric acid SPEEK 90 and, especially, the piranha solution PEEK-PS 2:1-90, were demonstrated to be promising in promoting the rapid bioactivation of PEEK-based implants.

Parasites and diet of Serrasalmus maculatus in a hydroelectric reservoir in Brazil / Parasitos e dieta de Serrasalmus maculatus em um reservatório no Brasil

Abstract Serrasalmus maculatus is a species of piranha which, despite being abundant in a reservoir environment, has few studies related to its parasitological and diet aspects. Thus, we aimed to document the parasitic fauna and diet of the S. maculatus in a hydroelectric reservoir in Brazil. In addition, we perform two literature reviews for the Neotropical region, recording the parasitic fauna already associated with S. maculatus and the occurrence of parasite genera identified in this study parasitizing Characiformes from other aquatic systems. Thirty-one hosts were collected with gillnets, from August 2014 to September 2016. Serrasalmus maculatus had a piscivorous feeding habit and a low richness parasitic component community, including two taxa of monogeneans, Anacanthorus lepyrophallus and Mymarothecium sp.; no endohelminths were observed. Data from the literature review, together with the findings of the study, showed that S. maculatus in the Neotropical region harbors 25 helminth taxa, with the monogenean being the most prevalent parasitic group and Brazil is the country with the most reports of the parasitic genera. These findings provide information on the relationships between diet, social behavior, and parasitic fauna of S. maculatus and on the patterns of distribution and infection of the observed parasite rates.

Resumo Serrasalmus maculatus é uma espécie de piranha que, a despeito de ser abundante em ambiente de reservatório, possui poucas informações sobre seus aspectos parasitológicos e dieta. Assim, o presente estudo objetivou documentar a fauna parasitária e a dieta de S. maculatus em um reservatório brasileiro. Além disso, foram realizadas duas revisões literárias para a região Neotropical, registrando a fauna parasitária, já associada a S. maculatus e a ocorrência dos gêneros parasitários identificados neste estudo, registrados em outros peixes Characiformes em outros sistemas aquáticos. Foram coletados 31 hospedeiros com redes de espera entre agosto de 2014 e setembro de 2016. Serrasalmus maculatus apresentou hábito alimentar piscívoro e comunidade componente parasitária com baixa riqueza, incluindo dois táxons de monogenéticos, Anacanthorus lepyrophallus e Mymarothecium sp.; não foram observados endohelmintos. Dados da revisão da literatura, juntamente com os achados deste estudo, mostraram que S. maculatus, na região Neotropical, abriga 25 táxons de helmintos, sendo monogenéticos o grupo de parasitos mais prevalente, e o Brasil o país com mais relatos de parasitos. Estes resultados fornecem informações sobre as relações entre dieta, o comportamento social e a fauna parasitária de S. maculatus e sobre os padrões de distribuição e infecção das taxas de parasitos observadas.

Surface Bioactivation of Polyether Ether Ketone (PEEK) by Sulfuric Acid and Piranha Solution: Influence of the Modification Route in Capacity for Inducing Cell Growth.

The aim of this study was to promote bioactivity of the PEEK surface using sulfuric acid and piranha solution. PEEK was functionalized by a sulfuric acid treatment for 90 s and by piranha solution for 60 and 90 s. Chemical modification of the PEEK surface was evaluated by infrared spectroscopy, contact angle analysis, cytotoxicity, cell adhesion and proliferation. The spectroscopy characteristic band associated with sulfonation was observed in all treated samples. PEEK with piranha solution 60 s showed an increase in the intensity of the bands, which was even more significant for the longer treatment (90 s). The introduction of the sulfonic acid functional group reduced the contact angle. In cytotoxicity assays, for all treatments, the number of viable cells was higher when compared to those of untreated PEEK. PEEK treated with sulfuric acid and piranha solution for 60 s were the treatments that showed the highest percentage of cell viability with no statistically significant differences between them. The modified surfaces had a greater capacity for inducing cell growth, indicative of effective cell adhesion and proliferation. The proposed chemical modifications are promising for the functionalization of PEEK-based implants, as they were effective in promoting bioactivation of the PEEK surface and in stimulating cell growth and proliferation.

Wolf Piranha vs Storz Prostate Morcellation Devices: A Retrospective Multi-Institutional Study.

Purpose: Holmium laser enucleation of the prostate (HoLEP) entails both enucleation and morcellation. Only three popular prostate morcellation devices are available for this procedure. In this study, a retrospective review was done to compare the Wolf® and Storz® morcellators. Materials and Methods: After Institutional Review Board approval, a multi-institutional retrospective chart review of prospectively collected data was performed at two institutions with a single surgeon at each center performing HoLEP. Thunder Bay Regional Health Sciences Center employed the Storz morcellator while Baylor Scott and White Medical Center used the Wolf. Preoperative, perioperative, postoperative, and demographic data for both sets of patients were analyzed and compared retrospectively. Results: A total of 506 patients in the Wolf cohort and 60 patients in the Storz cohort were analyzed. Morcellated pathologic weight was 52.3 g in the Wolf arm and 101.7 g on the Storz arm (p < 0.0001). Overall, average morcellation rates were faster in the Storz arm; morcellation rate was 5.8 g/min for Wolf, and 6.7 g/min in the Storz (p = 0.0015). Morcellator malfunction was significantly lower in Wolf cohort 0% vs 6.6% in the Storz (p = 0.0001), but this did not significantly slow morcellator efficiency times. The total number of mucosal bladder injuries was comparable with rates of 1.4% and 1.6% in the Wolf and Storz groups, respectively (p = 0.59). The duration of hospital stay and catheterization were <24 hours in both groups. Conclusions: In this retrospective study, the Storz DrillCut had higher efficacy in morcellation when compared with Wolf Piranha. However, it was associated with more malfunctions. Both morcellators have comparable rates of complications and perioperative outcomes.

Bite force mechanics and allometry of piranha (Serrasalmidae).

The bite force of the piranha (Serrasalmidae) has drawn considerable attention due to its ability to effectively capture and masticate prey. Herein, we analyze theoretical anterior bite forces using a lever approach and compare them to in-vivo maximum bite forces. We provide a mechanics analysis that explains the scaling allometry of the bite force (Foutput) with the length of the fish (l), Foutputαl2.

The recovery of sulfuric acid from spent piranha solution over a dimensionally stable anode (DSA) Ti-RuO2 electrode.

Piranha solution is a highly acidic mixture of sulfuric acid and hydrogen peroxide. The present study aimed at developing a dimensionally stable anode (DSA), made of titanium metal foil coated with Ruthenium Dioxide (RuO2), for the electrochemical oxidation of hydrogen peroxide in the presence of strong sulfuric acid under ambient conditions. Results showed that hydrogen peroxide in the piranha solution was fully degraded in 5 h under a constant current of 2 A (or current density of 0.32 A-cm-2). The oxidation kinetics of hydrogen peroxide followed the Langmuir-Hinshelwood model. The observed rate constant was a function of applied current. The initial current efficiency was 17.5% at 0.5 A (or 0.08 A-cm-2) and slightly decreased to about 13.5% at applied current between 1.3 and 1.5 A (or current density of 0.208 and 0.24 A-cm-2). Results showed the capability and feasibility of the electrochemical oxidation process for the recovery of sulfuric acid from the spent piranha solution in semiconductor industrial installations or general laboratories.

Hepatic coccidiosis in Serrasalmus rhombeus Linnaeus, 1766 from the Amazon basin: morphological and histopathological aspects / Coccidiose hepática em Serrasalmus rhombeus Linnaeus, 1766 da Amazônia paraense: aspectos morfológicos e histopatológicos

Abstract Calyptospora species are coccids that commonly cause liver infections in fish all around the world. This paper describes the morphology and histopathological characteristics of liver infection caused by Calyptospora sp. in black piranha Serrasalmus rhombeus, from the Capim River, in the municipality of Ipixuna do Pará, state of Pará (Brazil). Specimens were collected, analyzed and necropsied and tissue fragments containing parasites were prepared for histology and scanning electron microscopy. Parasitism was detected in 33.0% of the analyzed specimens, which had spherical oocysts in the liver, with four pyriform sporocysts presenting sporozoites internally. A histological examination revealed oocysts positioned close to blood vessels, causing necrosis and degeneration of hepatic parenchyma, while the presence of mononuclear cell infiltrate and melanomacrophages indicated the onset of an inflammatory process. This is the first record of the genus Calyptospora in fish from the Capim River.

Resumo Calyptosporídeos são coccídeos constantemente encontrados causando infecções hepáticas em peixes de todo o planeta. Este estudo descreve a morfologia e características histopatológicas da infecção hepática causada por Calyptospora sp. encontrados em Serrasalmus rhombeus, a piranha negra, oriunda do rio Capim, em Ipixuna do Pará, Brasil. Os animais foram coletados, analisados e necropsiados; fragmentos teciduais com a presença dos parasitos foram processados para histologia e microscopia eletrônica de varredura. O parasitismo ocorreu em 33,0% dos espécimes analisados, onde foram encontrados oocistos esféricos no fígado, com esporocistos piriformes, apresentando internamente esporozoítos. No exame histológico, os oocistos estavam dispostos próximos aos vasos sanguíneos, causando necrose e degeneração do parênquima hepático; a presença de infiltrado de células mononucleares e melanomacrófagos indicaram o início de um processo inflamatório. Este é o primeiro registro do gênero Calyptospora em peixes do rio Capim.

Phylogenomics of the Neotropical fish family Serrasalmidae with a novel intrafamilial classification (Teleostei: Characiformes).

The Neotropical fish family Serrasalmidae comprises 16 extant genera and 101 species widespread through major Neotropical rivers with relevant importance for regional fisheries and aquaculture. The monophyly of Serrasalmidae and the recognition of three main clades are recurrent between morphological and molecular phylogenies. However, both intergeneric and interspecific relationships within each of those clades remain uncertain. Here, we used 81 terminals of 69 species (68%) and all 16 genera of Serrasalmidae to sequence 1553 loci of ultraconserved elements (UCEs), multiple nuclear loci widely applied in phylogenetic studies, and performed maximum likelihood, Bayesian, and species tree analyses. We obtained highly supported phylogenies in all applied methods corroborating the monophyly of Serrasalmidae and the three-clade hypotheses herein proposed as two subfamilies and two tribes: (Colossomatinae (Serrasalminae (Myleini + Serrasalmini))). Morphological features for each subfamily involve the absence (Colossomatinae) or presence (Serrasalminae) of a pre-dorsal spine. Morphological diagnoses among tribes include the pre-dorsal spine being continuous (Myleini) or discontinuous (Serrasalmini) relative to the first unbranched dorsal-fin ray. Our results highlight the complexity of the relationships especially the non-monophyly of Myleus, Mylesinus, Myloplus, Tometes, and Utiaritichthys within Myleini, as well as of Serrasalmus and Pristobrycon within Serrasalmini.

Bond Strength Durability of Adhesive Cements to Translucent Zirconia: Effect of Surface Conditioning.

PURPOSE: To evaluate the influence of airborne particle abrasion, Piranha acid and hot acid etching on bond strength of zirconia with self-adhesive resin cements after aging. Also, the effect of Silano-Pen treatment on the bond strength of zirconia to resin cements. MATERIALS AND METHODS: Thirty-six zirconia blocks were cut, sintered and divided into three groups (n=12); Airborne particle abrasion, Piranha acid, and hot acid etching were then treated with Silano-Pen. Each zirconia block was bonded to its corresponding composite block utilizing either Panavia SA, TheraCem or Panavia F2.0. 360 micro -tensile test bars were obtained and half of them were subjected to 10000 thermal aging cycles. Each microtensile test bar was subjected to microtensile force until debonding. Scanning Electron Microscopic evaluation was performed. RESULTS: There was a significant difference between the surface treatments. Hot acid showed the highest mean bond strength and the lowest was Piranha acid. Panavia SA significantly improved the bond strength compared to TheraCem and Panavia F2.0. The interaction between cement and Silano-Pen was non-significant (p=.067). Under SEM analysis, hot acid treatments showed homogenous granular texture with wide distribution of porous network. CONCLUSIONS: Pre-treatment, resin cement, and aging influences the effectiveness of bonding of zirconia. Silano-Pen after hot acid improved the bonding of zirconia.

Cadaveric ichthyofauna of the Madeira River in the Amazon basin: the myth of man-eating piranhas.

Drowned bodies rescued from the rivers of the Amazon basin exhibit several artefacts caused by the actions of the cadaveric ichthyofauna, namely, the "candiru". This study aims to review and discuss the fish species responsible for the largest number of attacks on bodies in the Madeira River (Porto Velho - Rondônia, Brazil), to describe the feeding strategies and types of lesions caused by each species, and to demystify the myth of the "man-eating piranhas". To the best of our knowledge, this study is the first that aims to provide a systematic analysis of cadaveric ichthyofauna and forensic findings in this region.

Refutation of media reports on introduction of the red bellied piranha and potential impacts on aquatic biodiversity in India.

The presence of a new, potentially deadly exotic fish resembling the Red Bellied Piranha, Pygocentrus nattereri was reported in India by print media from various aquatic resources. These reports raised dramatic concerns over public health issues and threats to the aquatic biodiversity of India. Considering the potential severity of the issue and concerns raised by the media, we undertook a study to evaluate the reliability of identification reports of the suspected fish, any relationships to other species of piranha and to address any possible threats to the aquatic biodiversity of India. For this study, samples were collected from most of the major river systems and lakes in India and evaluated for taxonomic identifications of the suspect fish and phylogenetic relationships to other fish species. Our results clearly show that the suspect fish is in fact Piaractus brachypomus, a species commonly referred as "Pacu", and not the red bellied piranha, P. nattereri. Comparisons of both fish do show striking similarities that may account for the misreporting in the media. Furthermore, P. brachypomusas is still an exotic fish, and as such may still have potentially harmful impacts on the native aquatic fauna of India. Quick attention to this issue and the imposition of control measures, including market bans, should be considered to prevent further loss of biodiversity.

Stress-reducing and anesthetic effects of the essential oils of Aloysia triphylla and Lippia alba on Serrasalmus eigenmanni (Characiformes: Serrasalmidae)

Anesthetic effect of Aloysia triphylla and Lippia alba essential oils (EOs) in the Amazonian fish Serrasalmus eigenmanni was evaluated. The fish were placed in aquaria containing A. triphylla or L. alba EOs (25 to 200 µL L-1). Then, fish were transferred to aquaria containing EO-free water to evaluate their recovery time. In another experiment, fish were transferred to aquaria containing A. triphylla or L. alba EOs (3 to 10 µL L-1) and swimming behavior was analyzed for up to 240 min of exposure. Water samples were collected at 0 and 240 min and blood samples were collected at 240 min. Tested concentrations induced all stages of anesthesia, except 25 µL L-1 A. triphylla EO and 50 µL L-1 L. alba EO, which only induced sedation. Prolonged exposure to both EOs reduced swimming time compared to the control at all evaluated times. The fish exposed to 3 µL L-1 A. triphylla EO showed a lower net K+ efflux compared to ethanol-exposed fish; in those exposed to 5 µL L-1, ammonia excretion was reduced. The blood parameters did not show significant differences between treatments. In conclusion, both EOs can be used as anesthetics and sedatives for transport of S. eigenmanni.(AU)

Avaliou-se o efeito anestésico dos óleos essenciais de Aloysia triphylla e de Lippia alba no peixe amazônico Serrasalmus eigenmanni. Os peixes foram colocados em aquários contendo OEs de A. triphylla ou L. alba (25 a 200 µL L-1). Após, foram transferidos para aquários com água sem anestésicos para avaliar o tempo de recuperação. Em outro experimento, peixes foram transferidos para aquários contendo OEs de A. triphylla ou L. alba (3 a 10 µL L-1) e o comportamento natatório foi analisado até 240 min de exposição. Foram coletadas amostras de água em 0 e 240 min e de sangue em 240 min. As concentrações testadas induziram todos estágios de anestesia, exceto 25 µL L-1 OE de A. triphylla e 50 µL L-1 OE de L. alba, que causaram somente sedação. Exposição prolongada a ambos OEs reduziu o tempo de natação comparado ao controle. Peixes expostos a 3 µL L-1 OE de A. triphylla apresentaram menor efluxo de K+ comparado aos expostos ao etanol e nos expostos a 5 µL L-1 a excreção de amônia reduziu. Parâmetros sanguíneos não diferiram entre tratamentos. Conclui-se que ambos OEs podem ser utilizados como anestésicos e no transporte de S. eigenmanni.(AU)