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1.
K. MOLNÄR 《Journal of fish diseases》1982,5(6):461-470
Abstract. In the intestinal epithelium of 3–5-summer old tench, Tinca tinca L., an unknown Eimeria sp. developing white, pinhead-sized nodules was found. Oocysts were shed in a non-sporulated state, but at 20°C in tap water they completed sporulation and resembled Eimeria subepithelialis , a parasite of common carp. During the period of examination, in April and May, only young oocysts and gamogonic stages developing in the epithelium of the mucosa were detected. Despite the morphological similarities and nodular occurrence there are significant differences between the nodular coccidiosis of the tench and common carp. 相似文献
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G. D. LIO-PO M. C. L. BATICADOS C. R. LAVILLA M. E. G. SANVICTORES 《Journal of fish diseases》1985,8(4):359-365
Abstract. Pure cultures of the fungus Haliphthoros philippinensis isolated from infected Penaeus monodon larvae were exposed for 24 h to varying concentrations of the antifungal agents Benlate, calcium hypochlorite, clotrimazole, copper sulphate, Daconil, formalin, Fungitox, Furanace, griseofulvin, hydrogen peroxide, malachite green, Mysteclin C, phenol, potassium permanganate, Resiguard, Tide, tolnaftate and Treflan. The efficiency of each compound in inhibiting sporulation and mycelial growth of the fungus was measured. The results establish mycostatic and mycocidal levels for each fungicide. 相似文献
3.
J. S. LANGDON 《Journal of fish diseases》1991,14(1):33-44
Abstract. Microsporidiosis in the freshwater crayfish Cherax tenuimanus (Smith), or marron, was found to be due to a pleistophorid characterized by a single sporulation sequence producing eight, 16, 32 or 64 monomorphometric spores in a sporophorous vesicle with a fine two-layered wall. Infection occurred predominantly in locomotor, cardiac and gastrointestinal striated muscle. The disease ranged from subclinical infections where haemocytic encapsulation and infiltration of the spore masses controlled its progress, to fulminant disease with multifocal infection in the absence of effective haemocytic responses. The lethal lesions in the latter cases appeared to be those in the proventriculus. Prevalence of infection and incidence of mortality were low. The same microsporidian was found in subclinically infected C. quinquecarinatus (Gray) and C. quadricarinatus (von Mortens). 相似文献
4.
The effects of water temperature on the development of the enteric myxosporeans, Enteromyxum fugu and Enteromyxum leei, were investigated in experimentally infected tiger puffer, Takifugu rubripes. After naïve tiger puffer were fed gut tissue infected with both E. fugu and E. leei, they were divided into separate tanks and kept at different constant temperature regimes between 10 and 25 °C. Regardless of the water temperature tested, E. fugu was consistently detected with a high prevalence of infection (60–100%), although no sporulation occurred at 10 and 15 °C. Development of E. leei and the onset of disease were suppressed by low water temperatures (<15 °C). However, a temperature increase to 20 °C promoted the development of E. leei, followed by an increase of disease rate in the fish. The present study demonstrates that water temperatures below 15 °C have an inhibitory effect on the development of E. fugu and E. leei, resulting in suppression of enteromyxosis at low temperatures. 相似文献
5.
Year-round induction of sporogenesis of Laminaria saccharina was performed by mechanically blocking the transport of the putative sporulation inhibitors produced by the blade meristem and culturing the plants in constant short days. Sporogenesis was successfully induced by removal of the blade meristem, either by cultivating distal blade fragments or by performing a transverse cut in the frond. The earliest sorus formation after artificial induction was 10 days. The age of the sporophytes used for induction was 6–11 months or 2 years in tank-grown or field-collected sporophytes, respectively. Zoospores were successfully released in all cases. Thus, by year-round artificial induction of sporogenesis, (1) sporeling production of L. saccharina and thereafter sporophyte cultivation could be achieved without seasonal limitation, and (2) the life cycle of L. saccharina (from spore to spore) could be completed within 8 months under controlled conditions. 相似文献
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Abstract. The present knowledge of oocyst morphology, life cycles, classification and pathogenicity of eimeriid coccidia infecting fishes is reviewed. Compared with typical Eimeria species from higher vertebrates, fish coccidia, currently classified as all belonging to the same genus, differ in having, as a rule, a thin oocyst wall and endogenous sporulation. Some species possess a bivalved sporocyst, a structure and consequently an excystation mechanism, essentially different from that of the genus Eimeria. An analysis of the life cycles of more than 120 recorded species of fish coccidia has shown six different types of developmental patterns. The life cycles offish coccidia are compared with the life cycles of coccidia in general. None of the fish coccidia having a sporocyst with a Stieda body sporulates exogenously and therefore do not display a true eimerian developmental pattern. In view of the importance of sporocyst structure and developmental patterns in taxonomy, the revalidation of Labbé's genera Goussia and Crystallospora is proposed along with the establishment of a new genus, Epieimeria n.g. Most of the species offish coccidia are left within the genus Eimeria until new data make possible their correct classification. Detailed data on histopathological changes are available only in infections by two carp-infecting species, E. carpelli and E. subepithelialis and E. funduli infections in killifishes. The potential threat of coccidiosis in fishes reared under intensive conditions requires a thorough study of the pathogenicity of further species infecting commercially important hosts. 相似文献
9.
摘要:该研究以具有群体感应抑制作用的地衣芽孢杆菌(Bacillus licheniformis)T-1为试验对象,参照国标的急性毒性实验方法检测其对动物的安全性及对水体生态环境的影响。安全评价试验采用异育银鲫、斑马鱼、小鼠为测试动物,结果显示:异育银鲫腹腔注射浓度为11200mg/L(2.6×1011 CFU/Ml)菌株T–1菌液后,连续观察96h,异育银鲫均健康生长,未出现不良症状或死亡;将斑马鱼浸泡在浓度为2240mg/L(5.2×1010 CFU/mL)的菌株 T–1菌液中,连续观察96h,斑马鱼均健康生长,未出现不良症状或死亡;SPF级小鼠(ICR品系)灌胃16800 mg/kg(3.9×1011 CFU/mL)体重浓度的菌株T-1,观察9d小白鼠健康生长无不良症状。水体生态评价采用小球藻、大型蚤及萼花臂尾轮虫为测试对象,不同浓度的菌株T-1在96h内,对小球藻生长无毒且促进其生长,对大型蚤生长无不良影响,对萼花臂尾轮虫生长无害,且在高浓度下对萼花臂尾轮虫的生长繁殖有促进作用。研究表明,具有群体感应抑制作用的地衣芽孢杆菌T-1对异育银鲫、斑马鱼及小鼠安全无毒害;对水体生态环境中的浮游生物也无不良影响,具有开发成微生态制剂的潜力。 相似文献
10.
Carole R. Engle Jonathan van Senten Gary Fornshell 《Journal of the World Aquaculture Society》2019,50(3):522-549
The economic effects of the implementation of regulations on aquaculture farms in the United States, while of concern, are not well understood. A national survey was conducted of salmonid (trout and salmon) farms in 17 states of the United States to measure on‐farm regulatory costs and to identify which regulations were the most costly to this industry segment. The response rate was 63%, with a coverage rate of 94.5% of the U.S. production of salmonids. The regulatory system resulted in increased national on‐farm costs of $16.1 million/year, lost markets with a sales value of $7.1 million/year, lost production of $5.3 million/year, and thwarted expansion attempts estimated at $40.1 million/year. Mean farm regulatory costs were $150,506/farm annually, or $2.71/kg; lost markets with annual sales values of $66,274/farm; annual lost production of $49,064/farm; and an annual value of thwarted expansion attempts estimated at $375,459/farm. Smaller‐scale farms were affected to a disproportionately greater negative extent than larger‐scale farms. Per‐farm regulatory costs were, on average, greater for foodfish producers than for producers selling to recreational markets, but per‐kg regulatory costs were greater for those selling to recreational compared to foodfish markets. Regulatory costs constituted 12% of total production and marketing costs on U.S. salmonid farms. The greatest regulatory costs were found to be effluent discharge regulations. The majority of regulatory costs were fixed costs, but regulatory barriers to expansion precluded compensatory adjustments to the business in spite of growing demand for salmonid products. Results of this study show that the on‐farm regulatory cost burden is substantial and has negatively affected the U.S. salmonid industry's ability to respond to strong demand for U.S. farm‐raised salmonid products. Results also suggest that the regulatory system has contributed to the decline in the number of U.S. salmonid farms. While regulations will necessarily have some degree of cost to farms, the magnitude of the on‐farm regulatory cost burden on U.S. salmonid farms calls for concerted efforts to identify and implement innovative regulatory monitoring and compliance frameworks that reduce the on‐farm regulatory cost burden. 相似文献
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通过对金鱼(Carassius auratus var.)的5个代表品种草金(grass goldfish)、红龙睛(red dragoneye goldfish)、鹤顶红(red-head wen goldfish)、水泡(blisters-eyegoldfish)、黑寿(white-head oval goldfish)线粒体DNA细胞色素b基因全序列进行测定,结果发现金鱼Cytb基因全序列1141bp,其中T、C、A、G4种碱基含量分别为29.1%,27.8%,28.4%,14.5%,A T的含量(57.8%)高于C G的含量(42.2%)。草金、红龙睛、鹤顶红、水泡、黑寿Cytb基因全序列一样。结果表明,细胞色素b基因在金鱼种内是相当保守的,草金、红龙睛、鹤顶红、水泡、黑寿起源于同一祖先。将鲫鱼和金鱼线粒体Cytb基因序列比较分析,同源性达97.9%,应该还在同一种的水平上。 相似文献
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Abstract. Severe melanotic liver and visceral fibroses in bluegill associated with infections of plerocercoids of Proteocephalus sp. and metacercariae of the digenean Posthodiplostomum minimum , were studied by light and transmission electron microscopy. Fibrosis was most evident in bluegill carrying heavy worm burdens. Tubular and multilocular melanotic and non-melanotic cysts were formed of concentric layers of non-cellular eosinophilic connective tissue surrounding central spaces containing basophilic material. Moribund and deteriorating plerocercoids and metacercariae were surrounded by, and sometimes invested with, fibrous tissue. Living plerocercoids in the liver were surrounded by necrotic and compressed hepatocyte zones. Fibro-blasts, epithelioid cells and eosinophilic granulocytes were common in compressed cell zones. Intrahepatic fibrotic cysts were surrounded by granulomatous zones. Parenchyma in fibrotic livers showed increased numbers of macrophages, melano-macrophage centres and engorged blood vessels with thickened walls. Histochemical tests for lipofuscin and haemosiderin were strongly positive in melanotic liver tissue. Ultrastructural changes in hepatocytes adjacent to fibrotic cysts and epithelioid zones included intranuclear lipid and glycogen inclusions, chromatin alterations and mitochrondrial degeneration. Bile canaliculi, sinusoids and perisinusoidal spaces showed reduced micro villarsurfacesand a decrease in luminar diameter. Degenerating hepatocytes contained phagolysosomes and myelin bodies. 相似文献
14.
通过对金鱼(Carassius auratus var.)的5个代表品种草金(grass goldfish)、红龙睛(red dragoneye goldfish)、鹤顶红(red-head wen goldfish)、水泡(blisters-eye goldfish)、黑寿(white-head oval goldfish)线粒体DNA细胞色素b基因全序列进行测定,结果发现金鱼Cyt b基因全序列1 141 bp,其中T、C、A、G 4种碱基含量分别为29.1%,27.8%,28.4%,14.5%,A+T的含量(57.8%)高于C+G的含量(42.2%)。草金、红龙睛、鹤顶红、水泡、黑寿Cyt b基因全序列一样。结果表明,细胞色素b基因在金鱼种内是相当保守的,草金、红龙睛、鹤顶红、水泡、黑寿起源于同一祖先。将鲫鱼和金鱼线粒体Cyt b基因序列比较分析,同源性达97.9%,应该还在同一种的水平上。 相似文献
15.
During macroscopic post-mortem examinations of the genital tract in 104 mares endometrial cysts occurred in 14 (13%) cases. Whereas in mares up to the age of 10 years cystic changes were absent, endometrial cysts occurred in 19% of the animals above the age of 10 years. In 6 mares only 1-2 cysts per uterus were found, and in 8 animals there were between 5 and 18 cystic changes per organ. The cysts were equally distributed in the uterus body and horns. Sporadically occurring cysts were about 11 mm in diameter with a decreasing size to a mean value of 5 mm in multiple cysts. Predominantly in the uterus body very large cysts were found. The largest endometrial cyst was of 30 mm in diameter. Classification into lymphatic cysts and glandular cysts was made based on histological examinations. 相似文献
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J. C. MODIN 《Journal of fish diseases》1981,4(3):203-211
Abstract. A microsporidian parasite, Microsporidium rhabdophilia n. sp. is described from rodlet cells of salmonid fishes. Chinook salmon, Oncorhynchus tshawytscha , coho salmon, Oncorhynchus kisutch , steelhead rainbow trout, Salmo gairdnerii gairdnerii , and various strains of domesticated rainbow trout were found infected. In living wet mount phase-contrast observations of various tissues, 16 mature spores could be seen infecting the nucleus of rodlet cells. The number of spores infecting each nucleus generally numbered 16 and spores were not found in any cell or organelle other than the nucleus of the rodlet cell. All observations were limited to California hatchery-reared fish. 相似文献
17.
Spermatophore Generation Times in Penaeus setiferus, P. vannamei, and P. stylirostris 总被引:1,自引:0,他引:1
Joanna R. Leung-Trujillo Addison L. Lawrence 《Journal of the World Aquaculture Society》1991,22(4):244-251
Spermatophore development times were studied in three species of penaeid shrimp, Penueus setifcrus, P. vannumei , and P. stylirosrris . In the terminal ampoule, the progression of spermatophore formation occurred in 4 stages (I-IV). The duration of each stage varied with species and ablation state. In unablated males, with spermatophores manually or electrically removed, structnrally complete spermatophores containing high numbers of morphologically normal sperm were formed in 2–4 days for P. vannamei , 4–6 days for P. stylirostris and 5–7 days for P. setiferus . Unilateral eyestalk ablation of P. setiferus accelerated spermatophore production time by approximately 2 days, and significantly increased spermatophore weight and sperm count without affecting sperm quality.
Spermatophore removal techniques had little effect on development time in P. vannamei . However, in P. setiferus , new spermatophores were produced faster in males mating naturally than in those males whose spermatophores were removed electrically. 相似文献
Spermatophore removal techniques had little effect on development time in P. vannamei . However, in P. setiferus , new spermatophores were produced faster in males mating naturally than in those males whose spermatophores were removed electrically. 相似文献
18.
Abstract The lesions of an enterococcal septicaemia occurring in turbot, Scophthalmus maximus (L.), cultured in several farms in northwest Spain are described. The agent of this septicaemia was identified previously as an Enterococcus -like bacterium. Two main patterns of lesions were observed in the diseased turbot: a focal form characterized by exophthalmia, muscular haemorrhages, acute branchitis, and suppurative inflammation of periorbital tissues, eyeball, meninges and brain; and another generalized form with similar lesions, but showing more extensive haemorrhages, ulceration and purulent inflammation of the skin, desquamative enteritis, and necrosis of spleen and kidney. Fatty changes of the liver were observed in all turbot examined (diseased and controls), which indicates that these alterations were not related to the infection. Experimentally inoculated turbot developed lesions corresponding to the generalized form of the natural disease. Although the Enterococcus strain was recovered in pure culture from all the organs, Gram-positive bacteria could not be visualized histologically in the lesions of muscle and brain. 相似文献
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H H Sambraus 《Tier?rztliche Praxis》1988,16(1):13-19
Due to motorization the heavy horses, in particular draught horses and carriage horses, were deprived of their "raison d'être". At present therefore, they mostly are found in small livestocks. The past few years they regained some significance through their work in the forests, as an attraction in tourism or somewhere else. In German speaking countries approximately 15 horse breeds must be considered to be threatened in their existence. Breeding history, appearance, use and geographical distribution of 12 of them are discussed in this article. 相似文献
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Larviculture of the Greasy Grouper Epinephelus tauvina F. and the Brown-Marbled Grouper E. fuscoguttatus F. in Singapore 总被引:1,自引:0,他引:1
L. C. Lim 《Journal of the World Aquaculture Society》1993,24(2):262-274
This paper reports the larviculture of two grouper species, the greasy grouper Epinephelus tauvina and the brown-marbled grouper E. fuscoguttatus , and examines the technical feasibility of breeding the fish. Fertilized eggs for larviculture were obtained by induced spawning through multiple hormonal injections of the female brooders, followed by artificial fertilization for the greasy grouper and by natural spawning in netcages for the brown-marbled grouper.
For both species, larviculture was divided into three operational stages, i.e., stage 1 (day 0–12), stage 2 (from day 12 to day 24 for the greasy grouper and to day 30 for the brown-marbled grouper) and stage 3 (day 24 or 30 to metamorphosis). Larvae were transferred to clean tanks after each stage. Total mortality around day 5–8 was common for the greasy grouper. Several modifications, including the feeding with super-small strain rotifers, intensive feeding of rotifers with Nannochloropsis and the use of an oil-skimmer, have been made to improve the situation. Two other major problems in larviculture were the high mortality observed after day 25 in the greasy grouper and the high cannibalism from day 35 onwards for the greasy grouper and from day 30 onwards for the brown-marbled grouper. The shock syndrome exhibited by both species during the periods made culling of the fish impossible.
Based on the spawning and larval characteristics, brown-marbled grouper is considered a better potential species for large scale fry production than the greasy grouper. 相似文献
For both species, larviculture was divided into three operational stages, i.e., stage 1 (day 0–12), stage 2 (from day 12 to day 24 for the greasy grouper and to day 30 for the brown-marbled grouper) and stage 3 (day 24 or 30 to metamorphosis). Larvae were transferred to clean tanks after each stage. Total mortality around day 5–8 was common for the greasy grouper. Several modifications, including the feeding with super-small strain rotifers, intensive feeding of rotifers with Nannochloropsis and the use of an oil-skimmer, have been made to improve the situation. Two other major problems in larviculture were the high mortality observed after day 25 in the greasy grouper and the high cannibalism from day 35 onwards for the greasy grouper and from day 30 onwards for the brown-marbled grouper. The shock syndrome exhibited by both species during the periods made culling of the fish impossible.
Based on the spawning and larval characteristics, brown-marbled grouper is considered a better potential species for large scale fry production than the greasy grouper. 相似文献