Leeri Research Articles

Degenerative and Regenerative Actin Cytoskeleton Rearrangements, Cell Death, and Paradoxical Proliferation in the Gills of Pearl Gourami (Trichogaster leerii) Exposed to Suspended Soot Microparticles.

The effect is studied of water-suspended soot microparticles on the actin cytoskeleton, apoptosis, and proliferation in the gill epithelium of pearl gourami. To this end, the fish are kept in aquariums with 0.005 g/L of soot for 5 and 14 days. Laser confocal microscopy is used to find that at the analyzed times of exposure to the pollutant zones appear in the gill epithelium, where the actin framework of adhesion belts dissociates and F-actin either forms clumps or concentrates perinuclearly. It is shown that the exposure to soot microparticles enhances apoptosis. On day 5, suppression of the proliferation of cells occurs, but the proliferation increases to the control values on day 14. Such a paradoxical increase in proliferation may be a compensatory process, maintaining the necessary level of gill function under the exposure to toxic soot. This process may occur until the gills' recovery reserve is exhausted. In general, soot microparticles cause profound changes in the actin cytoskeleton in gill cells, greatly enhance cell death, and influence cell proliferation as described. Together, these processes may cause gill dysfunction and affect the viability of fish.

Effect of dietary fish and vegetable oil on the growth performance, body composition, fatty acids profile, reproductive performance and larval resistance in pearl gourami (Trichogaster leeri)

This study investigated the effect of two lipid sources on reproduction performance and growth in pearl gourami. For this purpose, 180 fish (3.32 ± 0.25 g) were fed with three isoenergetic (19.80) and isonitrogenous diets (480 g/kg protein) including FO (80 g/kg fish oil), FS (40 g/kg fish oil and 40 g/kg soybean oil) and SO (80 g/kg soybean oil) for 10 weeks before maturation. At the end of the trial, there was no significant difference in weight gain, feed conversation ratio and body composition between fish fed FO and FS diets. Individuals fed dietary FO had significantly higher levels of n‐3 long‐chain polyunsaturated fatty acids in the muscle (130.5 g/kg lipid) and ovary (140.4 g/kg lipid) as compared with those fed SO diet (64.5, 103.6 g/kg, respectively) (p < .05). Feeding pearl gourami with FO and FS diets enhanced regarding absolute fecundity, relative fecundity, the fertilization rate, larvae total length and survival at 3 day posthatch (p < .05). Also, 17 beta‐estradiol in plasma of fish fed dietary FO (6.2 ng/L) was higher than those fed SO diet (1.7 ng/L) (p < .05). In conclusion, we suggest FS diet for broodstock nutrition of pearl gourami as a model for asynchronous multi‐batch spawning fish.

Ornamental fishes in Khulna City, Bangladesh: culture practices and commercial aspects

An investigation was carried out to provide an initial assessment of aquarium fish trade from December 2018 to May 2019 in Khulna city, Khulna of Bangladesh. A total 12 shops were established in this district where 46 aquarium fish species were found of which 12 species were bred for fry production. In the study area, some ornamental fishes such as Gold fish, Black moor, Comet, Red parrot, Tiger barb, Angel fish, Black molly, Guppy, koi carp, Rosy barb, Silver shark, Rainbow shark, Tiger shark, Sucker mouth catfish, Blue gourami, Pearl gourami, Golden gourami, White molly, Pearl scale gold fish, Silver dollar, LT sucker fish were very common. Besides Glass catfish, Siamese fighting fish, calico, Swordtail, Oscar, Widow tetra, Neon tetra, Balloon molly, Moon tail balloon molly, Alligator gar were common and Tangerrine swordtail, Arowana, Flower horn, Red tail black shark, platy, cardinal tetra, Discuss fish, Rummy nose, Bolivian ram, Balloon ram, Bosemoni rainbow, Red tail catfish, Bichir, Mono angel, Knife fish were the rare fish of the Khulna city. All aquarium fish species were brought from catabon area of Dhaka city that were mainly imported from the international markets like India, Singapore, Thailand, etc. Importers/wholesalers and breeders marketed them to retailers, local breeders, shopkeepers, etc. and finally, the shopkeepers sold them to the aquaria owners. The most profitable large aquarium fishes were Gold fish which made a profit of (100±20 tk/pair), Black moor (150±20 tk/pair), Red parrot (250±50 tk/pair), angelfish (100±10 tk/pair), Pearl gourami (300±50 tk/pair), Guppy (400±50 tk/pair), Siamese Fighting Fish (300±50 tk /piece), Tiger Shark (40±10 tk/pair), Sucker mouth catfish (50±5 tk/pair) to the retailers. During this survey, it was found that the breeders used cement tank, glass aquaria, plastic tank and even plastic jar as culture tanks. They bred aquarium fish all over the year. In the present study the market is mainly domestic. There is a good domestic market which is increasing day by day. Except winter, average annual income was recorded 13,140,000 Tk from the 12 aquarium shops. However, when temperature dropped during winter, sale became reduced; sometimes no selling was also observed during this time.&#x0D; Asian Australas. J. Biosci. Biotechnol. 2019, 4 (3), 142-153

Terminalia catappa leaf extract is an effective rearing medium for larviculture of gouramis

ABSTRACTGouramis require soft and acidic waters for optimal development, and in this context, a cheap and effective culture medium is required. In this study, Pearl and Blue gourami larvae were raised in Terminalia catappa leaf extract (TCE), clear water, and green water, the latter containing 1 × 105 cells/ml Chlorella from Tilapia cultures. Larval survival and specific growth rate (SGR) were determined after 10 days of incubation. TCE was most effective in promoting survival of both gourami species, with the number of viable larvae augmented twofold and 30% in comparison to clear water and green water respectively. TCE was acidic, and this may have played a significant role in boosting survival, although larvae potentially benefited from the antioxidant and therapeutic properties of TCE. TCE significantly boosted growth, as evidenced by a significant increase in the specific growth rate, perhaps explained by the occurrence of additional live food such as Paramecium, Colpidium, and other infusorians. Although the effects of TCE are uncertain, its application enhanced larval performance of gouramis and perhaps blackwater fishes, a finding with potential application in aquaculture.

Interaction of carboxylated CdSe/ZnS quantum dots with fish embryos: Towards understanding of nanoparticles toxicity

Due to colloidal instability even with protective coatings, nanoparticles tend to aggregate in complex environments and possibly interact with biota. In this study, visualization of quantum dots (QDs) interaction with rainbow trout (Oncorhynchus mykiss) embryos was performed. Studies on zebrafish (Danio rerio) and pearl gourami (Trichogaster leerii) embryos have shown that QDs interact with embryos in a general manner and their affects are independent on the type of the embryo. It was demonstrated that carboxylated CdSe/ZnS QDs (4 nM) were aggregating in accumulation media and formed agglomerates on the surface of fish embryos under 1–12 days incubation in deep-well water. Detailed analysis of QDs distribution on fish embryos surface and investigation of the penetration of QDs through embryo's membrane showed that the chorion protects embryos from the penetration through the chorion and the accumulation of nanoparticles inside the embryos. Confocal microscopy and spectroscopy studies on rainbow trout embryos demonstrated that QDs cause chorion damage, due to QDs aggregation on the surface of chorion, even the formation of the agglomerates at the outer part of the embryos and/or with the mucus were detected. Aggregation of QDs and formation of agglomerates on the outer part of the embryo's membrane caused the intervention of the aggregates to the chorion and even partially destroyed the embryo's chorion. The incorporation of QDs in chorion was confirmed by two methods: in living embryos from a 3D reconstruction view, and in slices of embryos from a histology view. The damage of chorion integrity might have adverse effects on embryonic development. Moreover, for the first time the toxic effect of QDs was separated from the heavy metal toxicity, which is most commonly discussed in the literature to the toxicity of the QDs.

Monogenean parasites infect ornamental fish imported to Australia.

The ornamental fish trade provides a pathway for the global translocation of aquatic parasites. We examined a total of 1020 fish imported from Singapore, Malaysia, Thailand, or Sri Lanka to Australia (including freshwater and marine fish species) for monogenean ectoparasites. Fish were received following veterinary certification that they showed no clinical signs of pests and diseases from the exporting country and visual inspection at Australian border control. Australian import conditions require mandatory treatment for goldfish with parasiticides (e.g. trichlorfon, formaldehyde, sodium chloride) for the presence of gill flukes (Dactylogyrus vastator Nybelin, 1924 and Dactylogyrus extensus Mueller and Van Cleave, 1932) prior to export. Over 950 individual parasites were detected in five imported fish species, representing 14 monogenean species. Seven Dactylogyrus spp. including D. vastator and three Gyrodactylus spp. infected goldfish, Carassius auratus Linnaeus, 1758, from Malaysia, Singapore, and Thailand. Dactylogyrus ostraviensis Řehulka, 1988, infected rosy barb, Pethia conchonius Hamilton, 1822, from Singapore, Sri Lanka, and Thailand while two Trianchoratus spp. infected three spot gourami, Trichopodus trichopterus Pallas, 1970 and pearl gourami Trichopodus leerii Bleeker, 1852, from Sri Lanka. Urocleidoides reticulatus Mizelle & Price, 1964, infected guppy, Poecilia reticulata Peters, 1859, from Sri Lanka. The discovery of D. vastator in goldfish, as well as 13 other monogenean species, shows that pre-export health requirements, which include chemical treatment of goldfish, and inspection of all ornamental fish species did not prevent infection by monogeneans. Inspection prior to exportation and at border control must account for the highly cryptic nature of monogenean parasites and consider alternatives to current pre-export conditions and visual inspection at border control.

Influence of light colours on growth and stress response of pearl gourami Trichopodus leerii under laboratory conditions

This study aimed to investigate the influence of illumination with different light spectra on growth and stress response in pearl gourami Trichopodus leerii Bleeker, 1852. Fish (6.35 ± 0.43 cm, 5.69 ± 0.67 g) were reared in 8 glass aquaria each with 25 fish under one of four different lighting conditions: yellow (max 546 nm), red (max 605 nm), blue (max 470 nm) and white (control). Experiments lasted for 90 days. The stress response was evaluated by measuring cortisol levels. No significant effect was observed on final body weight, length and specific growth rate of fish. However, best values for these characteristics were achieved for fish reared under yellow light. A significant higher weight gain, condition factor was found in fish reared under yellow light compared with fish reared under blue or red light. In contrast, a lower final body weight, specific growth rate and weight gain were achieved for fish reared under red light. Feed conversion ratio was significantly lower in fish under yellow light compared with red or blue light. Stressed fish showed lower cortisol levels under yellow light compared with other light exposures. The study indicates that, pearl gourami grows better under yellow light and that yellow light lowers the stress-induced cortisol response.

Biological nutrient recovery from culturing of pearl gourami (Trichogaster leerii ) by cherry tomato (Solanum lycopersicum) in aquaponic system.

The possibility of using different densities of cherry tomato as a bio-filter in a simple media-based aquaponic system to recycle nutrients from pearl gourami intensive culture wastewater was evaluated. Water quality parameters including total ammonia nitrogen (TAN), nitrite (NO2-), nitrate (NO3-), phosphate (PO43-), pH, and dissolved oxygen (DO) were determined in outlet of the aquaponic system during a 60-day experimental period. Cherry tomato was planted at four densities of 0 (control), 3 (T1), 6 (T2), and 9 (T3) plants per aquaponic unit with a constant fish stock density. Each treatment was equipped with aquaponic systems containing fish tank and plant growing bed. Productivity of the system was measured by recording the fish and plant growth indices. The potential in removing nitrogen of the water was the highest in T3 (with nine plants) compared to other treatments (p<0.05). The highest concentrations of TAN (6.59±0.241mg/L), nitrite (0.42±0.005mg/L), nitrate (0.45±0.162mg/L), and phosphate (30.47±0.371mg/L) were obtained in control group, while the lowest concentrations of TAN (0.05±0.091mg/L), NO2- (0.11±0.008mg/L), NO3- (29.77±0.205mg/L), and phosphate (18.59±0.185mg/L) were detected in T3 (p<0.05). The maximum fish weight gain was recorded in T3 (26±0.014%) with 1.26±0.059 FCR, and the lowest fish weight gain was measured in the control group (15±0.024%) with 2.19±0.446 FCR (p<0.05). Total plant length gain was reached at the maximum value in T3 (74.70±1.153cm) in comparison to other groups (p<0.05). It was concluded that small-scale aquaponic growing bed system can be created a sustainable ecosystem which both the plant and fish can thrive and suitable for home-made production system.

Taste preferences, orosensory food testing, and sound production during feeding by the pearl gourami Trichopodus leerii (Osphronemidae)

It has been found that the pearl gourami Trichopodus leerii evaluates the quality of food objects (agar–agar pellets with standard size, shape, and color but having different composition) by touching them with their lips without using its long filamentous ventral fins. Orosensory testing is accompanied by repeated grasps−rejections−grasps of the pellets (up to 28 times). Such manipulations become significantly more frequent and the pellet is retained several times longer if the trial ends with ingestion rather than final refusal of the object by the fish. It has been found for the first time that pearl gourami produces clicking sounds while grasping the pellets. The number of sounds is directly related to the number of grasps of the object performed by the fish. Only two (alanine, serine) of 21 amino acids (L-isomers) were attractive to pearl gourami, another 13 acids turned out to be indifferent stimuli, and six acids had a repulsive taste. Pearl gourami was attracted to the taste of sucrose and Chironomidae larvae extract. The addition of citric acid, calcium chloride, and sodium chloride to the pellets did not influence their consumption by the fish. The more attractive the substances contained by the pellets, the longer time is spent by the fish on orosensory testing of the pellet quality.

Inter Simple Sequence Repeat (ISSR) and Cytogenetic Analysis of Three Fish Species of Family Osphronemidae

The ISSR-PCR and karyological analysis methods are successfully used to detect the genetic variations between the different species of fishes, especially these belonging to the same family. The aim of this study was to determine the karyotypes and molecular genetic variations of three species of family Osphronemidae, Trichogaster trichopterus, Trichogaster leeri and Colisa laliaby using ISSR-PCR and chromosomal analysis. Samples were collected from ornamental fish farms in Egypt. The diploid chromosome numbers and Fundamental numbers for species under study were 2n = 46 and FN = 46, 2n = 46 and FN = 46, 2n = 46 and FN = 70 respectively, the first two species have same karyotype but the third species was different. The ISSR-PCR analysis was carried out using ten primers. All primers were successfully amplified on the genomic DNA extracted from all studied fish species. These findings indicate that ISSR-PCR and cytogenetic analysis are very useful in determination of genetic molecular variations and relationship degree between the species which belong to same family.

Taste attractiveness of free amino acids and their physicochemical and biological properties (as exemplified by fishes)

Using fishes as an example (32 species, II families) the relationship between taste attractiveness of free amino acids (L-isomers) and their physicochemical and biological properties was analyzed. It is shown that the essential amino acids, which are of the highest nutritional requirement for an organism, have lower taste attractiveness in fishes than nonessential ones. Only in 6 species of 32 investigated ones (sun- bleak Leucaspius delineatus, European minnow Phoxinus phoxinus, dace Leuciscus leuciscus, chub Leu- ciscus cephalus, blue gourami Trichopodus trichopterus, pearl gourami Trichopodus leerii) the relation- ship between taste preference and molecular weight of amino acids was confirmed statistically, in all cases being negative. Only in 2 species a statically significant correlation between taste properties of amino acids and the dissociation constant (K₁) was found (positive in stone loach Barbatula barbatula and negative in lake charr Salvelinus namaycush). A positive correlation between taste preference and the value of isoelectric point (pI) of amino acids was found in one species (roach Rutilus rutilus) and negative correlation - in 2 species (brown trout Salmo trutta, Arctic char Salvelinus alpinus erythrinus). A significant correlation between taste attractiveness and solubility of amino acids in water.was found in 2 species (chum salmon Oncorhynchus keta and navaga Eleginus nawaga), negative in both cases. Acidic and polar uncharged amino acids more often possess flavor that stimulates food consumption than basic and non-polar ones, L-isomers of amino acids than D-isomers, amino acids with an amino group in cc-position than in β-position. Amino acids are more attractive than their salts. Aromatic amino acids possess attrac- tive taste much less than sulfur-containing or acyclic ones. Thus, in the majority of fish species the relationship between taste attractiveness of free amino acids and many of their physical, chemical and biolo- gical properties is absent or low, indicating their indirect nature and difficulty of revealing these relation- ships.

Prebiótico, probiótico e simbiótico para larvas de Trichogaster leeri (Bleeker, 1852, Perciformes, Osphronemidae)

RESUMO Avaliou-se a suplementação de prebiótico (mananoligossacarídeo - 2g/kg), probiótico (Bacillus subtilis, Cohn, 1872, Bacillales, Bacillaceae - 2g/kg) e simbiótico (mananoligossacarídeo - 2g/kg + B. subtilis - 2g/kg), em rações para larvas de Trichogaster leeri (Bleeker, 1852, Perciformes, Osphronemidae), durante a transição alimentar, sobre o crescimento, a sobrevivência, a morfometria intestinal e a resistência ao estresse por exposição aérea. Para isso, 420 larvas (0,45±0,05mg) foram distribuídas em 20 aquários (3,5L), em delineamento inteiramente ao acaso, com cinco tratamentos e quatro repetições, durante 28 dias, a saber: 12 dias de alimento vivo (AV) + oito dias de coalimentação (AV + ração controle) + oito dias de ração controle; 12 dias de AV + oito dias de coalimentação (AV + ração prebiótico) + oito dias de ração prebiótico; 12 dias de AV + oito dias de coalimentação (AV + ração probiótico) + oito dias de ração probiótico; 12 dias de AV + oito dias de coalimentação (AV + ração simbiótico) + oito dias de ração simbiótico; 28 dias de AV. Larvas que receberam apenas AV apresentaram resultados de desempenho zootécnico significativamente superiores às larvas dos demais tratamentos, exceto para taxa de crescimento específico em comprimento e sobrevivência, que foram semelhantes aos resultados obtidos por larvas que receberam rações suplementadas com simbiótico. Larvas que receberam a ração controle apresentaram resultados significativamente inferiores para altura das vilosidades intestinais e taxa de resistência ao estresse comparando-se aos demais tratamentos. Os resultados deste estudo indicam que a suplementação com prebiótico, probiótico e simbiótico exerce efeito positivo sobre a sobrevivência, a morfometria intestinal e a resistência ao estresse em larvas de T. leeri, no entanto somente a suplementação com simbiótico resulta em melhora no crescimento.

Effect of temperature during embryonic development and first feeding of Trichogaster leeri larvae.

Temperature is an environmental factor that influences the development of fish, and when changed abruptly can lead to high mortality. Some species of fish are influenced by this factor, exhibiting a longer time for embryonic development and time to first feeding. This study aims to evaluate the effect of water temperature on embryonic and larval development up to first feeding, to describe the time in hours post fertilization (hpf) of the emergence of different structures and to determine the best hatching rate and survival of animals under different treatments. Five different egg incubation temperatures were used (24, 26, 28, 30 or 32°C, respectively). The eggs were observed at regular intervals of 30 min up to 24 h, every 2 h until 48 h and every 4 h until the display of first feeding in all treatments. Embryonic development was longer for eggs incubated at 24°C and the best results for hatching rate and survival of spawning efficiency were at 28°C. We recommend that incubation of Trichogaster leeri eggs is carried out at 28°C up to the first feeding of larvae.

THE BIODIVERSITY OF NURSERY GROUND IN SWAMP AREAS IMPORTANT TO SURVIVE THE BLACK FISHES IN THE WETLAND

Fish nursery grounds are important for the life cycle of fishes and often these areas are not particularly well studied or the processes understood in Sumatra. On December 2014, The blackfishes in swamp ecosystem of South Sumatera consist of Channa striata, Clarias batrachus, Anabas testudineus, Trichogaster trichoterus, Polyacanthus hasselti, Rasbora argyrotaenia, Betta taeniata, Betta anabantoides, Monopterus albus, Notopterus notopterus, Trichogaster pectoralis, Trichogaster leeri, Oxyeleotris marmorata and Helostoma temmincki.. This observation is constitute first record of blackfishes in Sumatra. Keywords: First, nursery grounds, blackfishes, observation, sumatra.

The complete mitochondrial genome sequence of Trichopodus leerii (Perciformes: Osphronemidae) and phylogenetic studies of Osphronemidae

Trichopodus leerii has been given many popular names in the ornament market, such as pearl gourami, lace gourami and mosaic gourami, which causes confusion in species identification. This species belongs in the family Osphronemidae of Perciformes. This species and its congeners are characterized by a brownish-silver body, covered in a pearl-like pattern. In this study, we first determined and described the complete mitogenome sequence of T. leerii, which is 16,472 bp in length. The overall base composition is 29.2%, 27.3%, 28.0% and 15.5% for A, C, T and G, respectively, with a slight bias in the AT content (57.2%). All protein-coding genes share the start codon ATG and most of them have TAA or TAG as the stop codon, except ND4 and ND6 use an incomplete stop codon T. Maximum likelihood tree and Bayesian analyses based on partitioned nucleotide sequences of 12 mitochondrial protein-coding genes were constructed, and both yielded identical topologies. These results are expected to provide useful molecular data for species identification and further phylogenetic studies of Osphronemidae and Perciformes.

Complete mitochondrial genome of the Trichogaster leeri (Anabantoidei: Osphronemidae)

The complete mitochondrial genome of Trichogaster leeri is determined in this study. It is 16,454 bp in length and consists of 13 protein-coding genes, 2 rRNA genes, 22 tRNA genes and a non-coding control region (D-loop). The overall base composition of the heavy-strand (H-strand) of the T. trichopterus mitochondrial genome is A: 29.18%, T: 28.07%, C: 27.20% and G: 15.55%. The total length of the 13 protein-coding genes was 11,435 bp. Phylogenetic analysis showed that the species of Trichogaster (T. trichopterus, T. lalius and T. leeri) formed a monophyletic group and represented close relationship with the species of Anabantoidei. This study provides an important data set for phylogenetic and taxonomic analyses of the species of genus Trichogaster.

Disease resistance and immune‐relevant gene expression in golden mandarin fish, Siniperca scherzeri Steindachner, infected with infectious spleen and kidney necrosis virus‐like agent

Infectious spleen and kidney necrosis virus (ISKNV), family Iridoviridae, genus Megalocytivirus, may cause high mortality rates such as those seen in mandarin fish, Siniperca chuatsi. ISKNV has attracted much attention due to the possible environmental threat and economic losses it poses on both cultured and wild populations. We have investigated the pathogenicity of ISKNV-like agent Megalocytivirus, isolated from infected pearl gourami, in golden mandarin fish, Siniperca scherzeri - a member of the Percichthyidae family - and in another Percichthyidae species, S.chuatsi. Fish were challenged with four different doses of ISKNV-like agent Megalocytivirus (1, 10, 100 or 1000μg per fish) over a 30-day period, and cumulative fish mortalities were calculated for each group. No significant mortality was observed for fish challenged with the lowest dose (1μg per fish) relative to a control group. However, all other challenged groups showed 100% mortality over a 30-day period in proportion to the challenge dose. Quantitative real-time PCR was performed to measure mRNA expression levels for six immune-related genes in golden mandarin fish following ISKNV-like agent challenge. mRNA expression levels for IRF1, Mx, viperin and interleukin 8 significantly increased, while mRNA levels for IRF2 and IRF7 remained constant or declined during the challenge period.

Experiencias sobre cultivo de peces ornamentales en la Cooperativa COOPESCA, Acacias - Meta

The ornamental fish farming species in Meta province is still incipient, although that can be a source of livelihood for many rural and urban families. However, to achieve growth of the business is essential and appropriate to generate the necessary knowledge on the biology, behavior and appropriate adaptation techniques and captive management of potentially cultivable species. The captive culture offers the possibility to diversify production, produce better quality animal husbandry and health, ensure continuous supply and help reduce pressure on wild populations generated by the indiscriminate extraction. Currently at the regional level, only few species have standardized protocols for captive breeding and cultivation on a commercial scale. Therefore, this study sought to characterize some productive variables four ornamental species of commercial interest to the cooperative COOPESCA: blue gourami (Trichogaster trichopterus), pearl gourami (Trichogaster leeri) betta (Betta splendens) and scalar (Pterophyllum scalare). Variables were analyzed water quality, growth and physical development, nutrition, health and infrastructure used. The observations were made between August and December 2011. Overall, of the four species, 210 animals were monitored, grouped according to age and body size. In all groups, the increases in weight and height were directly proportional to feed intake. The water temperature was maintained at 21.5 ± 2.3 °C, the pH at 7.1 ± 0.6 and 49.5 ± conductivity 23 µS. Information collected to provide guidance to organize processes and make local production more profitable, so that it becomes an alternative employment and income for the fishing community, as well as strategy for the conservation, protection and recovery aquatic species and natural resources of the municipality of Acacias, Meta - Colombia.

수입산 담수관상어 및 양식 해산어의 장내세균에서 나타나는 내성균 위험성 비교

Various antibiotics, that could induce the appearance of resistant microorganisms, have been used for treatment or prevention of bacterial diseases in marine and ornamental fish. We determined and characterized the level of antibiotic-resistant bacteria and proportion of multi-drug resistant bacteria in intestinal microflora of both marine fish cultured in Korea and imported ornamental freshwater fish. For this the bacterial species and resistance to antibiotics were investigated in intestine of rock bream Oplegnathus fasciatus cultured in Korea and pearl gourami Trichogaster leeri imported from Singapore to characterise. Although the bacterial species were different, proportions of resistant bacteria to single antibiotics or multi-drug were higher in intestinal microflora of pearl gourami Trichogaster leeri imported from Singapore than in rock bream Oplegnathus fasciatus cultured in Korea. These results indicate that various antibiotics have been being used before trading without measures in the market of asian ornamental fishes, providing high risks for the emergence of multi-drug resistant bacteria.

Digestibilidade aparente de alimentos proteicos e energéticos para Trichogaster leeri

O experimento foi conduzido para determinar digestibilidade aparente (CDA) da matéria seca (MS), energia bruta (EB) e proteína bruta (PB) da farinha de peixe (FP), farinha de carne e ossos (FCO), farelo de soja (FS), farelo de milho (FM) e farelo de trigo (FT) pelo Trichogaster leeri. Foram utilizados 20 peixes por aquário. Os aquários eram cilíndricos, fundo cônico, com 100 litros cada. A determinação dos CD foi feita por intermédio da metodologia de coleta total de fezes. As médias de temperatura, oxigênio dissolvido e pH durante o período experimental foram de 25,0 ± 1,13 oC; 3,91 ± 0,91mg/L e 5,22 ± 0,87, respectivamente. Os CD da MS, PB e EB foram respectivamente de 68,63, 89,25 e 87,30 para FP; 54,90, 65,95 e 80,62 para FCO; 60,13, 82,19 e 85,46 para FS; 39,30, 89,87 e 89,74 para FM; 22,5,17,45 e 19,54 para FT.