Small-scale environmental enrichment and exercise enhance learning and spatial memory of Carassius auratus, and increase cell proliferation in the telencephalon: an exploratory study

Carassius auratus is a teleost fish that has been largely used in behavioral studies. However, little is known about potential environmental influences on its performance of learning and memory tasks. Here, we investigated this question in C. auratus, and searched for potential correlation between exercise and visuospatial enrichment with the total number of telencephalic glia and neurons. To that end, males and females were housed for 183 days in either an enriched (EE) or impoverished environment (IE) aquarium. EE contained toys, natural plants, and a 12-hour/day water stream for voluntary exercise, whereas the IE had none of the above. A third plus-maze aquarium was used for spatial and object recognition tests. Different visual clues in 2 of its 4 arms were used to guide fish to reach the criteria to complete the task. The test consisted of 30 sessions and was concluded when each animal performed three consecutive correct choices or seven alternated, each ten trials. Learning rates revealed significant differences between EE and IE fish. The optical fractionator was used to estimate the total number of telencephalic cells that were stained with cresyl violet. On average, the total number of cells in the subjects from EE was higher than those from subjects maintained in IE (P=0.0202). We suggest that environmental enrichment significantly influenced goldfish spatial learning and memory abilities, and this may be associated with an increase in the total number of telencephalic cells.

Prevalence of Centrocestus formosanus Metacercariae in Ornamental Fish from Chiang Mai, Thailand, with Molecular Approach Using ITS2

The prevalence of Centrocestus formosanus metacercariae was investigated in ornamental fish purchased from a pet shop in Chiang Mai, Thailand, including Carassius auratus (goldfish), Cyprinus carpio (Koi), Poecilia latipinna (Sailfin Molly), Danio rerio (Zebrafish), and Puntigrus tetrazona (Tiger barb). The parasite species was identified by the morphology of worms as well as by a molecular approach using ITS2. The results showed that 50 (33.3%) of 150 fish examined were infected with the metacercariae. The highest prevalence was found in C. auratus (83.3%), and the highest intensity was noted in C. carpio (70.8 metacercariae/fish). The most important morphological character was the presence of 32–34 circumoral spines on the oral sucker. The phylogenetic studies using the rRNA ITS2 region revealed that all the specimens of C. formosanus in this study were grouped together with C. formosanus in GenBank database. This is the first report on ornamental fish, C. carpio, P. latipinna, D. rerio, and P. tetrazona, taking the role of second intermediate hosts of C. formosanus in Thailand. Prevention and control of metacercarial infection in ornamental fish is urgently needed.

Ectocommensal and ectoparasites in goldfish Carassius auratus (Linnaeus, 1758) in farmed in the State of São Paulo / Ectocomensais e ectoparasitas em kinguios Carassius auratus (Linnaeus, 1758) criados em fazenda no Estado de São Paulo

Concomitant infections by several parasitic genera are rare, very debilitating and often lethal to fish reared under commercial breeding conditions. Were describe a multiple and concurrent parasite infestation in cultured goldfish Carassius auratus with skin damage (nodules and/or ulceration). Fish with skin lesions underwent necropsy, and the skin and gills were scraped and examined. Histopathological examination with Hematoxylin-Eosin and Giemsa stain, and an ultrastructure study using transmission and scanning electron microscopy were conducted. In the skin, we identified multiple-parasite infestations by Gyrodactylidae, Epistylis sp., Trichodina sp., Ichthyophthirius multifiliis, Tetrahymena sp. and Ichthyobodo necator,associated with epithelial cell hyperplasia and epidermal sloughing. Although no gross lesions were observed, were identified a large number of parasites in the gills (Epistylis sp., Piscinoodinium sp., Ichthyophthirius multifiliis, Trichodina sp., Apiosoma sp., Hexamitasp. and cysts of a trematode digenean). The observed trematodes were not identified. The associated microscopic lesions were epithelial hypertrophic and hyperplasic and exhibited fusion of secondary lamellae and epithelial cell detachment. This is the first description of a protozoan Vorticella sp. parasitizing goldfish in Brazil. Multiple ectoparasitism by protozoa and Platyhelminthes, with or without apparent tissue damage, can be fatal for goldfish raised on farms with poor management.

A infestação concomitante por vários gêneros de parasitas é uma condição rara, debilitante e letal para os peixes e está geralmente associada aos problemas ambientais e de manejo. Com o objetivo de descrever os ectoparasitos presentes em kinguios Carassius auratus com lesões cutâneas, cultivados em fazenda comercial, foram analisados 30 exemplares de peixes por esfregaços de pele lesionada e de brânquias; exame histopatológico de tecidos corados pela técnica de Hematoxilina-Eosina e Giemsa e estudo ultraestrutural por microscopia eletrônica de transmissão e varredura de tecidos coletados após necropsia. Nas lesões cutâneas, foram observados os parasitos: Gyrodactylidae, Epistylis sp., Trichodina sp., Ichthyophthirius multifiliis, Tetrahymena sp. e Ichthyobodo necator, associados à hiperplasia epitelial, descamação epidérmica e presença de infiltrado inflamatório. A infestação das brânquias, mesmo sem lesão macroscópica, evidenciou Epistylissp., Piscinoodinium sp., I. multifiliis, Trichodina sp., Apiosoma sp., Hexamita sp. e cistos de trematódeo associados à hipertrofia e hiperplasia epitelial, fusão de lamelas secundárias, descamação epitelial e presença de infiltrado inflamatório. Os trematódeos observados não foram identificados. É a primeira descrição do protozoário Vorticella sp. parasitando kinguios no Brasil. O ectoparasitismo múltiplo por protozoários e platelmintos, com ou sem lesão aparente, pode ser fatal em peixes cultivados em condições ambientais precárias.

Effects of selected metal oxide nanoparticles on multiple biomarkers in Carassius auratus / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the biological effects of nanoscale copper oxide (nCuO), zinc oxide (nZnO), cerium dioxide (nCeO2) and their mixtures on Carassius auratus.</p><p><b>METHODS</b>Juvenile fish (Carassius auratus) were exposed to aqueous suspensions of nCuO, nZnO, and nCeO2 (alone and in mixtures) at concentrations of 20, 40, 80, 160, and 320 mg/L. The biomarkers-acetylcholinesterase (AChE) in brain, sodium/potassium-activated ATPase (Na+/K+-ATPase) in gill, and superoxide dismutase (SOD) and catalase (CAT) in liver-were determined after 4 days of exposure. Integrated biomarker response (IBR) was calculated by combining multiple biomarkers into a single value.</p><p><b>RESULTS</b>AChE and SOD activities were significantly inhibited by all test metal oxide nanoparticles (NPs) at high concentrations (⋝160 mg/L) with the exception of nCeO2. Na+/K+-ATPase induction exhibited bell-shaped concentration-response curves. CAT activity was significantly inhibited at concentrations equal to or higher than 160 mg/L. The order of IBR values was nCeO2 ≈ nZnO/nCeO2 ≈ nCuO/nCeO2 < nCuO/nZnO/nCeO2 < nZnO < nCuO < nCuO/nZnO. The joint effect seemed to be synergistic for nCuO/nZnO mixtures, additive for the ternary mixture and less than additive or antagonistic for the binary mixtures containing nCeO2.</p><p><b>CONCLUSION</b>Concentration-dependent changes of enzymatic activities (AChE, Na+/K+-ATPase, SOD, and CAT) were observed in fish exposed to nanoscale metal oxides. IBR analysis allowed good discrimination between the different exposures and might be a useful tool for the quantification of integrated negative effects induced by NPs toward fish.</p>

Single and combined effects of estrone and 17β-estradiol on male goldfish / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To assess the single and combined effects of estrone (E1) and 17β-estradiol (E2) on goldfish (Carassius auratus).</p><p><b>METHODS</b>Batch tests were conducted. Serum levels of vitellogenin (VTG) and E2, gonadosomatic indices (GSI), gonadal DNA damage and liver 7-ethoxyresorufin-O-deethylase (EROD) activity were measured after exposure for 14 days.</p><p><b>RESULTS</b>The VTG level increased significantly in a concentration-dependent manner. The serum E2 level was significantly higher and the GSI level was significantly lower in goldfish after exposed to the 3 drugs. DNA damage occurred in treated samples and EROD activity was significantly suppressed 7 days after exposure. The joint effect of E1 and E2 was additive with regard to VTG induction.</p><p><b>CONCLUSION</b>The results of our study highlight a series of effects of steroidal estrogens on goldfish. Further study is needed to confirm their effect as a whole.</p>

Influence of photoperiod and temperature on reproduction and gonadal maturation in Goldfish: Carassius auratus.

There and great variety of reproductive styles in fish, usage of aquaculture in increasing fish production needs to have a proper understanding of endocrine physiology. In this study three different sets of experiment were designed 19L/5D at 200C, 12L/12D at 200C, 18L/6D at 200C photoperiod and temperature effects on these experimental regimes on reproduction are compared with control group. The gonadal maturation was assessed by microscopic and histological obervations. Gonadosomatic index (GSI) have been calculated. The results from our research revealed that at 19L/15D at 200C temperature the gonads are in more developed conditions than other photoperiodic regimes. GSI values is also high. Therefore,it was concluded that long photoperiod are useful to accelerate gonadal activity in goldfish Carassius auratus.

Crescimento e sobrevivência de larvas de peixe vermelho (Carassius auratus) alimentadas com microdietas comerciais / Growth and survival of Carassius auratus larvae fed commercial micro diets

Para avaliar o desempenho de dois alimentos comerciais para larvas de peixes ornamentais e analisar o efeito que a suplementação em vitaminas e minerais teria sobre a sobrevivência e o crescimento dessas, foi realizado um ensaio de crescimento de 21 dias, com 4800 larvas de peixe vermelho (Carassius auratus), distribuídas por 24 grupos (200 indivíduos por grupo). Cada grupo foi alojado em tanques de 5L de capacidade, ligados a um sistema de recirculação de água. Quatro grupos foram alocados a um controle de jejum, em que os animais não foram alimentados, e os restantes 20 grupos foram utilizados em cinco tratamentos, em quadruplicado. Em cada um dos cinco tratamentos, os peixes ingeriram uma das seguintes dietas: R (referência), C1 (SERA vipan® baby), C2 (SERA® microgran), C1v e C2v (C1 e C2, respectivamente, reforçadas em vitaminas e minerais). As taxas de sobrevivência e crescimento dos peixes do tratamento R foram maiores que as obtidas nos outros tratamentos (P<0,05). Foram ainda observadas diferenças significativas entre tratamentos relativamente ao comprimento e peso totais. Face aos resultados observados, conclui-se que as duas dietas comerciais, com e sem suplementação, não parecem ser adequadas para o preenchimento das necessidades nutricionais de larvas de peixe vermelho.

A 21-day growth trial was performed to evaluate two ornamental fish larvae commercial diets and the effect of mineral and vitamin supplementation of the same commercial microdiets on growth and survival of goldfish larvae (Carassius auratus). A total of 4,800 larvae were randomly distributed in 24 groups of 200 individuals. Each group was housed in a 5L tank, connected to a recirculating water system. Four groups were assigned to a fastening control. The animals in these groups did not receive any food. The remaining 20 groups were distributed in five treatments, in quadruplicate. The animals of each treatment were fed one of five experimental diets: R (reference), C1 (SERA vipan® baby), C2 (SERA® microgran), C1v, and C2v (C1 and C2, respectively, reinforced with minerals and vitamins). At the end of the trial, high survival and growth rates were observed in R treatment. There were significant differences in total length and total weight among dietary treatments. Considering the high survival and growth rates of goldfish larvae obtained with the reference diet, it can be concluded that the two commercial diets tested, with or without mineral and vitamin supplements, do not seem suitable for feeding goldfish larvae.

Chlorpheniramine impairs functional recovery in Carassius auratus after telencephalic ablation

We determined the effect of an H1 receptor antagonist on the functional recovery of Carassius auratus submitted to telencephalic ablation. Five days after surgery the fish underwent a spatial-choice learning paradigm test. The fish, weighing 6-12 g, were divided into four groups: telencephalic ablation (A) or sham lesion (S) and saline (SAL) or chlorpheniramine (CPA, ip, 16 mg/kg). For eight consecutive days each animal was trained individually in sessions separated by 24 h (alternate days). Training trials (T1-T8) consisted of finding the food in one of the feeders, which were randomly blocked for each subject. Animals received an intraperitoneal injection of SAL or CPA 10 min after the training trials. The time spent by the animals in each group to find the food (latency) was analyzed separately at T1 and T8 by the Kruskal-Wallis test, followed by the Student Newman-Keuls test. At T1 the latencies (mean ± SEM) of the A-SAL (586.3 ± 13.6) and A-CPA (600 ± 0) groups were significantly longer than those of the S-SAL (226.14 ± 61.15) and S-CPA (356.33 ± 68.8) groups. At T8, the latencies of the A-CPA group (510.11 ± 62.2) remained higher than those of the other groups, all of which showed significantly shorter latencies (A-SAL = 301.91 ± 78.32; S-CPA = 191.58 ± 73.03; S-SAL = 90.28 ± 41) compared with T1. These results support evidence that training can lead to functional recovery of spatial-choice learning in telencephalonless fish and also that the antagonist of the H1 receptor impairs it.

L-histidine reduces inhibitory avoidance in Carassius auratus submitted to cerebellar ablation

The effect of post-training treatment with L-histidine (LH) on the memory consolidation of inhibitory avoidance was investigated in Carassius auratus submitted to cerebellar ablation. The inhibitory avoidance procedure included 3 days: one habituation day, one training day (5 trials, T1-T5) and one test day. On the training day, each fish was placed individually in a white compartment separated from a black compartment by a sliding door. When the fish crossed into the black compartment, a weight was dropped in front of it (aversive stimulus) and the time to cross was recorded. Saline or LH (100 mg/kg) was injected intraperitoneally 10 min after the trials. Data were log10 transformed and analyzed by ANOVA and the Student-Newman-Keuls test (P < 0.05). In T5, all groups [ablation/LH (N = 15; 189.60 ± 32.52), ablation/saline (N = 14; 204.29 ± 28.95), sham/LH (N = 14; 232.36 ± 28.15), and sham/saline (N = 15; 249.07 ± 25.82)] had similar latencies that were significantly higher than T1 latencies [ablation/LH (89.33 ± 20.41), ablation/saline (97.00 ± 25.16), sham/LH (73.86 ± 18.42), and sham/saline (56.71 ± 17.59)], suggesting acquisition of inhibitory avoidance. For the test, there was a significant reduction in latencies of ablation/LH (61.53 ± 17.70) and sham/saline (52.79 ± 25.37) groups compared to the ablation/saline (213.64 ± 29.57) and sham/LH (199.43 ± 24.48) groups, showing that cerebellum ablation facilitated retention of inhibitory avoidance and LH reversed the effect of ablation. The results support other evidence that LH impairs memory consolidation and/or reduces the interpretation of aversion value.

Initial sexual maturity and fecundity of the goldfish Carassius auratus (Perciformes: Cyprynidae) under semi-controlled conditions

We studied the time of initial sexual maturity and the fecundity of the goldfish Carassius auratus under semi-controlled conditions. During the study the water temperature fluctuated from 21 to 30 degrees C, the pH between 7 and 8, and the dissolved oxygen between 5.5 and 7 ppm. Sixty days old juvenile fish received prophylactic treatments of brackish water (15 per thousand) and methylene blue baths (1%), and they were fed with live Daphnia magna. The initial sexual maturity occurred between 225 and 233 days of captivity. Mean absolute fecundity was 2,347 (+/- 302.2 SD) ova per gonad, and mean relative fecundity was 63.44 eggs/g fish weight. Gonadosomatic index was between 7.5 and 9.0. Our data will allow ornamental fish producers to calculate the time of initial maturity and fecundity for this species.

Estudiamos el tiempo inicial de madurez sexual y la fecundidad del pez dorado Carassius auratus en condiciones semi-controladas. Durante el estudio la temperatura del agua varió de 21 a 30 oC, el pH entre 7 y 8, y el oxígeno disuelto entre 5.5 y 7 ppm. Jóvenes de 60 días de edad recibieron tratamiento profiláctico con agua salobre (15 ‰), y baños de azul de metileno (1 %). Se les alimentó con Daphnia magna. La madurez sexual inicial fue tras 225 a 233 días en cautiverio. La fecundidad absoluta media fue de 2 347 (±302.2 DS) óvulos por gónada y la fecundidad relativa fue de 63.44 óvulos/g del peso del pez. El índice gonadosomático se calculó entre 7.5 and 9.0.

Isolation of Bdellovibrio Bacteria from the Gut of Carassius auratus gibelio and the Study of its Biological Characteristics / 微生物学通报

Bdellovibrio bacteria BDF-H16 was isolated from the gut of Carassius auratus gibelio with Aeromonas sobria.Its shape was ob- served by light microscopy,phase-contrast microscopy,electron microscopy and some of its biological characteristics were also studied.It was demonstrated that BDF-H16 was an gram-negative bacterium and had a bacilliform or arc bacilliform shape with a flagellum at one end.Its size was mostly 0.2?m～0.5?m?0.8?m～1.2?m.It had a wide prey area and could lyse all tested gram-negative bacteria and some gram-positive bacteria.The best lysis conditions to Escherichia coli were 6.75?10~9 cfu/mL of prey bacteria concentration,pH7.0～7.5,28℃.It could grow in the solid culture added 0.85%～5.00% NaCl and was inhibited by enrofloxacin and norfloxacin.

THE GROWTH PROPERTY OF THE PATHOGENIC BACTERIUM CSS-4-2 OF THE BACTERIAL SEPTICEMIA OF CARASSTUS AURATUS OF PENZE(♀)? CYPRINUS ACUTIDORSALIS(♂) / 微生物学通报

The growth property of pathogenic bacterium Aeromonas caviae strain CSS-4-2 which was isolated from the spleen of Carassius auratus of penze(♀) ? Cyprinus acutidorsalis (♂) that diseased septicemia was studied.The growth curve of CSS-4-2:lag phase was in 0～3h,log phase was in 3～30h, stationary phase was in 33～36h,decline phase was after 36h when CSS-4-2 was cultured shaking in tryptone liquid medium. It's optimum growth temperature ranges from 25℃ to 30℃, optimum growth pH ranges from 5 to 10, and optimum salinity ranges from 0% to 1% Nacl concentration .

STUDY ON THE BACTERIAL SEPTICEMIA OF CARASSIUS AURATUS OF PENZE(♀)? CYPRINUS ACUTIDORSALIS(♂)I——ISOLATION AND IDENTIFICATION OF THE PATHOGEN / 微生物学通报

The bacterial strain CSS-4-2 isolated from the spleen of Carassius auratus of penze(♀) ? Cyprinus acutidorsalis (♂) with septicemia was proved to b e a pathogen by artificial infection. This bacteria has short rod-shaped cells , Gram negative and motile, with single polar flagellum, and with not capsule. No spore was formed , and it was resistant to 0/129. It could utilize glucose, mal t ose ,mannite, sucrose and inositol, but could not utilize malonate, lactose, xyl ose, raffinose, sorbin and adonitol. Oxidase and arginine dihydrolase was posit ive.While urease, lysine decarboxylase and ornthine decarboxylase was negative .Bacteriological identification by VITEK-AMS-60 showed the strain CSS-4-2 w as Aeromonas caviae. Drug sensitivity assay showed that this strain was sen sitive to s treptomycin, tobramycin, chloromycetin, rifampicin, norfloxacin and nitrofuranto in, but resistant to penicillin G.

Effects of Printing and Dyeing Wastewater Before and After Bacterial biotechnological Treatment on Specific Immune Response of Carassius auratus / 环境与健康杂志

In order to explore the effects of printing and dyeing wastewater untreated and treated by bacterial biotechnological method on the specific immune response of Carassius auratus, the tested fish were preimmunized intraperitoneally with Aeromonas hydrophila vaccine then were separately placed into control clean water,untreated printing and dyeing wastewater (dilution ratio 13%,pH=7) and treated water 5 fish of every group were killed on the day 2,4,6,8,10,14,18,25,35 th to detect their immune indexes The results indicated that total leucocytic numbers of blood and serum lysozyme level in fish of clean water and treated water increased rapidly and reached their peaks on the day 8th and 6th respectively after vaccination,then reduced to baseline and maintatined for a period of time Leucocytic numbers in fish in untreated wastewater group decreased on day 2nd then increased gradully to normal,serum lysozyme level in this group had decreasing tendency and was lower than the other 2 groups from beginning to end However titer of anti A hydrophila antibody in serum of untreated water group was only lower than that of treated water group on the day 6th when it appeared After this antibody titers of these 3 groups had no significant defference It indicated that printing and dyeing wastewater inhibited immune response of Carassius auratus ,but water treated by bacterial biotechnological method had no this kind of toxic effect