摘要:

In North America fishery research is approached by almost as many administrative avenues as there are agencies engaged in it. Between these agencies differences exist in needs, plans, staff organization, methods of enlisting public support, and in the application of research findings. This situation is desirable. In the comparative infancy of fishery science any tendency toward development of stereotyped doctrine should be deplored. Originality and eclecticism should be encouraged, both in training institutions and in research and administrative bodies. An objective review of apparent successes and failures to date, however, may prove of value in illuminating pitfalls and in pointing out procedures which have resulted in progress. From this review profitable methods and promising areas for future activity may be inferred by the reader.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1953)83[212:FRAM]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1954

数据来源: Taylor

摘要:

The most recent advancement in control of external organisms causing fish disease is the pond-treatment method. It is an improvement over the hand-dipping method because fish are not killed by handling, fewer men are needed to carry it out, and the pond itself is treated along with the fish. All external parasites are controlled by a treatment with formalin (diluted to 1:4000) for an exposure of 1 hour, except Ichthyophthirius multifiliis, parasitic copepods, and species of Saprolegnia. I. multifiliis can be controlled by holding affected fish in swiftly running water for several weeks or by chemical treatment of the water for the duration of the life cycle of the parasite. Free-swimming larvae of the copepod Salmincola edwardsii can be killed by chemical added to the water; because of the parasite's long life cycle, treatment would hardly be feasible at large hatcheries. Saprolegnia sp. (fungus) can be killed readily by dipping fish in a 1:15,000 solution of malachite green for 10 to 30 seconds, or by introduction of the chemical into the pond for 45 minutes at a dilution of 1:180,000. Fish eggs can be kept fungus-free by semi-weekly treatments with a 1:200,000 concentration of malachite green.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1953)83[221:AIPATO]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1954

数据来源: Taylor

摘要:

The clearest evidence for the hereditary determination of diseases in fishes comes from the genetic studies of melanomas. This neoplastic disease in platyfish-swordtail hybrids is initiated, intensified, or inhibited by genetic factors. The development of melanomas depends upon the interaction of a sex-linked, dominant gene obtained from the platyfish and a number of dominant modifying genes obtained from the swordtail. During the past 5 years, evidence has been discovered for the hereditary influence in the development of thyroid tumors in a species of Mexican swordtails. The disease closely resembles the well known thyroid tumors in trout, described about 50 years ago. Kidney tumors of thyroid-cell origin have been detected in several strains of platyfish. In other strains of the same species, living under similar conditions and diets, the kidney tumors have not developed. Several examples are presented of death of fish embryos from hereditary causes. Some skeletal abnormalities of fishes may be traced to injurious genes. The hereditary factors involved in diseases and abnormalities are generally complex and difficult to detect, but the evidence for their existence is undeniable.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1953)83[229:TGOFD]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1954

数据来源: Taylor

摘要:

A review is made of the progress in research on bacteria which are pathogenic to fish, with particular emphasis on those investigations performed during the past decade. The report includes a critical review of material published; the comments and suggestions are designed to stimulate the initiation of new research projects.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1953)83[241:TNOBPT]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1954

数据来源: Taylor

摘要:

Malnutrition in fish population, although recognized by the earliest workers in fish culture, has only recenty received intensive study commensurate with that in other fields of animal nutrition. Recent experimental test diets have produced specific deficiency syndromes for most of the vitamins and have indicated the possibility of developing specific deficiencies for amino acids, fatty acids, and other basic nutrients. During the past 3 years the first evidence of susceptibility to bacterial disease in lots of fish with sub-clinical manifestations of vitamin deficiencies has opened an entire new field in fish-disease study.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1953)83[254:FDAN]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1954

数据来源: Taylor

摘要:

This report deals with any abnormal tissue, the growth of which exceeds and is uncoordinated with that of the normal tissue. Included in this category are the neoplasia (benign and cancerous), non-functional hyperplasias, cellular hypertrophy as well as other atypical cell growths. The following topics are discussed with special reference to the temperate freshwater fishes of North America: papillomas, hyperplastic epidermal diseases (including fish pox), parasitic and neoplastic adenomas, carcinomas (incuding thyroid tumors), fibromas, fibro-sarcomas, myxomas, leiomyomas, rhabdomyomas, granulomas, lymphosarcomas, pigment-cell tumors, neurofibromas, neurilemmonas, hamartomas, and teratomas.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1953)83[262:TAOACG]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1954

数据来源: Taylor

摘要:

Investigations on infectious diseases of Pacific salmon due to micro-organisms other than viruses are reviewed. The etiological agents include trematodes, fungi, protozoa and bacteria. Bacteria have been found to be the most important agents of disease in the several species of Pacific salmon. Kidney disease, due to a small, unnamed Gram-positive diplobacillus, causes serious mortalities in young salmon reared in hatcheries. The disease has also been found in wild fish. Aquatic myxobacteria are important agents of disease both in the hatchery and in the natural habitat. One of the myxobacteria, Chondrococcus columnaris, causes disease at relatively high water temperatures. The problem of the taxonomy of this organism is discussed. Another myxobacterium, Cytophaga psychrophila, has been found responsible for epizootics in coho salmon at lower water temperatures, i.e., in the range of 40° to 55° F. In outbreaks of gill disease in young salmon, myxobacteria of several kinds have been implicated.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1953)83[297:IDOPS]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1954

数据来源: Taylor

摘要:

During the past decade considerable progress has been made in the therapy of bacterial fish diseases. This progress was possible largely because of the introduction of powerful chemotherapeutic agents such as sulfonamides and antibiotics.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1953)83[313:TOBFD]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1954

数据来源: Taylor

摘要:

Viruses are probably the cause of a wide spectrum of fish diseases. Although relatively few virus diseases of fish are known today, some of the diseases of unknown etiology, as well as some diseases presently accepted as due to bacteria, protozoa, fungi or nutritional deficiencies, possibly will be recognized eventually as virus diseases.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1953)83[331:VDOF]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1954

数据来源: Taylor

摘要:

Some of the achievements in selective breeding of animals for resistance to diseases are discussed. The literature on disease resistance among strains of trout within a species is reviewed. The known mechanisms of disease resistance are discussed in relation to the problem of creating maximum resistance through selective breeding.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1953)83[342:DODSOF]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1954

数据来源: Taylor