Health Management in Aquaculture
187-page book has eleven chapters on viral, bacterial, fungal, parasitic disease and pests, and the various ways to prevent and control these.
Celia R. Lavilla
- How disease develops
- Disease diagnosis
Gilda D. Lio-Po
- Characteristics of virus
- Major viral infections in fish
- Major viral infections in penaeid shrimps
- Prevention of viral infections
Eleonor V. Alapide-Tendencia and Leobert D. de la Peña
- What are bacteria?
- Identifying the real cause of a disease; Koch’s Postulates
- Important bacterial diseases of fish
- Bacterial diseases of crustaceans
Eduardo M. Leaño
- What are fungi?
- Major fungal diseases of fish
- Major fungal diseases of crustaceans
Parasitic diseases and pests
Erlinda R. Cruz-Lacierda
- Common fish diseases caused by parasites
- Common crustacean diseases caused by parasites
- Life cycle patterns of fish parasites
Environmental and other non-infectious diseases
- Fish diseases associated with physico-chemical properties of water
- Shrimp diseases associated with physico-chemical properties of water
- Diseases associated with physical factors
- Diagnosis of environmental and other non-infectious diseases
Celia R. Lavilla
- Types of feeds
- Components of feeds
- Determining the nutritional status of fish
- Nutritional deficiency diseases of fish
- Nutritional diseases of shrimps
- Feed quality problems with health implications
Physical, environmental, and chemical methods of disease prevention and control
Erlinda R. Cruz-Lacierda and Gregoria E. Erazo-Pagador
- Physical methods
- Environmental methods
- Chemical methods
Immunity and biological methods of disease prevention and control
Jesus Manolo E. Almendras
- The fish immune system
- The crustacean immune system
- Biological control
Immunological and molecular biology techniques in disease diagnosis
Leobert D. de la Peña
- Immunological techniques
- Molecular biology techniques
Harmful and toxic algae
Romeo D. Caturao
- Conditions that stimulate harmful and toxic algal blooms
- Types of harmful and toxic algal blooms
- Effects of harmful and toxic algal blooms to fish and marine environment
- Strategies in coping with the problem of harmful and toxic algal blooms
- Photo and figure credits
Book chapter- In GD Lio-Po, CR Lavilla & ER Cruz-Lacierda (Eds.), Health Management in Aquaculture, 2001 - SEAFDEC Aquaculture DepartmentThe improvement of existing immunoassay techniques, development of monoclonal antibody technology and the development of new immunoassay approaches are all working together to provide new tools for the detection of disease-causing organisms in fish and crustaceans. Following the introduction of nucleic acid hybridization technique and PCR, it was recognized that the methods offered a sensitive approach to the detection and identification of specific microorganisms as in the case of a bacterial or viral infection in a variety of sample types. Potentially, a characteristic DNA sequence from a single virus particle or cell of a particular organism can be amplified to detectable levels within a short period of time. Conventional diagnostic methods that involve the culture of microorganisms can take days or weeks to complete or very tedious to perform. PCR offers a rapid, very sensitive, very specific and simple alternative. Further developments in immunodiagnostics and emerging technologies such as DNA-based tests will revolutionize the detection and identification of infectious disease agents. The development of rapid, simple, sensitive and specific diagnostic tests for infectious diseases has been much slower than the other disciplines of medicine. This is partially attributed to the complexity and diversity of the pathogenic organisms and to the difficulty in detecting low concentrations of these organisms in samples. Immunological and molecular biology-based techniques are rapidly advancing the field of diagnostics in fish and shrimp diseases.
Book chapter- In GD Lio-Po, CR Lavilla & ER Cruz-Lacierda (Eds.), Health Management in Aquaculture, 2001 - SEAFDEC Aquaculture DepartmentA wide variety of parasites have been identified as causing significant economic losses in fish and shrimp culture. Most of these parasites are difficult to control effectively with a single measure. The control of parasites is dependent on culture systems of the host fish, knowledge of the life cycle of the parasite, and the availability of effective treatment methods.
Book chapter- In GD Lio-Po, CR Lavilla & ER Cruz-Lacierda (Eds.), Health Management in Aquaculture, 2001 - SEAFDEC Aquaculture DepartmentFish and crustaceans that are not weakened by poor environmental conditions, or by other causes, such as parasitic infestation, nutritional deficiency, handling stress, or chemical intoxication, are more resistant to bacterial infections. This is due to the presence of a large amount of bactericidal substances in the blood, which helps overcome infections. So, the best precaution against the occurrence of bacterial infections is to provide the fish with optimum environmental conditions, adequate amounts of the right kinds of food and avoidance of stress, including overcrowding. Vaccination/ immunization and genetic manipulation (i.e., the development of specific pathogen resistant fry) are also some ways of preventing bacterial diseases. The use of antibiotics should always be an option of the last resort.
Book chapterOutbreaks of viral infections can cause massive mortalities among cultured fishes or shrimps. Water temperature and age of the fish or shrimps are significant factors that influence the development of viral infections. Most fish viral infections occur at low water temperatures, hence, very few viral infections among fishes in warm water culture systems are reported. In addition, most viral infections occur among fry or fingerlings often causing severe mortalities, while older fish or shrimp develop resistance or are hardly affected. Stress from handling, poor water quality, high stocking density and poor nutrition also affect the severity of viral infections. Finally, aquaculturists should beware in importing non-indigenous fish or shrimps into the country as these are potential carriers of viral pathogens.
Book chapterThe chapter provides basic facts about harmful and toxic algae. It also discusses the conditions that stimulate their occurrence, different types of harmful and toxic algal blooms and their effects to fish and marine environment. The different strategies in coping with the problem of harmful and toxic algal blooms are also discussed.
Book chapterThe chapter deals with the barriers that prevent microbial entry and the various internal defense mechanisms that are part of the host's arsenal in combating in combating invading microbes. It also discusses some of the biological methods of disease prevention and control.
Book chapterDisease occurrence is one of the biggest deterrents to sustainable production in aquaculture. It is therefore important to enhance awareness among various sectors of the importance of health management in the aquaculture industry. This can be done through education and information dissemination. Students in fisheries and veterinary medicine need to have adequate background information on the aquatic animal disease and health management to understand the problems and needs of a fast-growing aquaculture industry. Recognizing disease signs early and using mortality pattern as a clue to the disease agent involved will not only make diagnosis easier, but it will also pre-vent massive losses by timely implementation of remedial measures.
Book chapterDisease prevention is primary and cost-effective method in fish health management. It is more effective and economical than attempting to stop a disease that has already set in. the recommendations given above will greatly reduce the possibility of disease outbreak.
Book chapterOver the past 20 years, aquatic animal mycopathogens have become the focus of considerable research. The many known occurrences of fungal diseases in wild populations and the documented devastating disease outbreaks indicate that fungal and fungal-like pathogens are important in nature. Fungal diseases can act as major limitations on natural and cultured populations of aquatic animals. However, knowledge on fungal diseases is rudimentary consisting primarily of the identification and pathology of etiological agents. Detection of fungal infections relies only on the observation of gross pathology, histological examinations, and standard mycological isolation and identification procedures. As a result, there are some cases where the implicated fungal pathogen cannot be demonstrated as the primary cause of a particular disease. In such cases, the fungal pathogen is usually regarded as secondary invader. Continued research in basic mycology is still an essential resource for fish pathologists in diagnosing diseases caused by fungi. Although fungi reportedly affect very few species, fungal diseases, if not properly controlled or prevented, can still pose a threat to the aquaculture industry.
Book chapterThe chapter presents some of the environmental non-infectious diseases of aquatic animals. Non-infectious diseases are caused by adverse environmental conditions, nutritional disorders, or genetic defects. While they can result a sudden mass mortality or death, they are not contagious. Environmental diseases are the most important in aquaculture. This includes low dissolved oxygen, high ammonia, high nitrite, or natural or man-made toxins in the aquatic environment.
Book chapterDiagnosis of nutritional diseases is difficult because many signs exhibited by fish are non-specific and most nutritional deficiencies are hard to define. A compilation of data on feed composition and feeding management, as well as husbandry practices, are needed to define a case. Most of data on fish and shrimp nutritional diseases were gathered under experimental conditions. Under farm conditions, most of that definition would be clouded with errors in husbandry practices or secondary infection. Therefore, attempts to diagnose nutritional diseases should be carefully done using every available technique to define the case.