Nutritional diseases

Diagnosis 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

Transboundary movement of exotic shrimp species in the Asian region.

This compiled information were based on presentations at the AQUAMARKET Shrimp Session in Manila, Philippines, 2-6 June 2003, made by T.W. Flegel (BIOTEC), C.V. Mohan (NACA), P. Chanratchakool (AAHRI), and C.R. Lavilla-Torres (SEAFDEC)

Luminescent Vibriosis in Cultured Black Tiger Shrimp Penaeus monodon(Department of Sciences for Biospheric Coexistence)

博士学位論文要

Health management in aquaculture

A textbook on diseases of cultured warmwater fish and shrimps in the Philippines. Eleven chapters cover essential information on the basic principles of disease causation, major diseases of cultured fish and crustaceans, particularly shrimps, and methods of prevention and control. Emphasis is made on major diseases that occur in the Philippines and other countries in the Asian region. Included also are topics on harmful algae, immunology and molecular biological diagnostic techniques.1st Ed

Isolation and culture in artificial media of Lagenidium from Penaeus monodon larvae

Fungal infection of P. monodon larvae is a problem in hatchery operations. The fungus, which attacks the nauplius to postlarval stages and causes up to 100% mortality, has been tentatively identified as belonging to the genus Lagenidium . This pathogenic organism has recently been isolated and cultured. A description is given of the fungus, and features of its biology and pathology are discussed

Selection of probiotics for shrimp and crab hatcheries

A study aimed at obtaining a biological control agent against bacterial diseases, specifically luminescent vibriosis, of hatchery-reared shrimps and crabs was done to find an alternative for chemotherapy as a disease prevention and control method. Bacteria were isolated from crustacean rearing environments where luminescent vibrosis was not observed, from natural food, and from various feed ingredients. From hundreds of purified strains, 80 bacterial isolates were tested in one-on-one mixed cultures in seawater for their ability to suppress the growth of luminescent Vibrio harveyi. Of the 10 isolates exhibiting that capability, two strains were further studied: C1 from chlorella culture and P9 from a commercial probiotic preparation. However, due to the indigenous nature of C1 strain from the unicellular alga Chlorella sp. and the ease in distinguishing it from other bacteria owing to its colony morphology, more tests were done on C1 strain. To determine the suitability of C1, and to some extent P9, as biocontrol bacteria, their pathogenicity against crab larvae and shrimp postlarvae, and their ability to become associated or incorporated into the larvae were determined. Incorporation into the rotifer, Brachionus, was also tested. Due to the positive results obtained in the incorporation experiments, the growth of strain C1 in microbiological media and unrefined media prepared from agricultural by-products was also tested

The Leiognathus aureus complex (Perciformes: Leiognathidae) with the description of a new species

Taxonomic analysis of a group of morphologically similar ponyfishes (Perciformes: Leiognathidae) establishes a complex comprising three valid species: Leiognathus aureus Abe and Haneda, 1972, widely distributed in the western Pacific Ocean (Taiwan, Philippines, Thailand, Singapore, Indonesia, and northern Australia); L. hataii Abe and Haneda, 1972, currently known only from Ambon, Indonesia; and L. panayensis sp. nov. Kimura and Dunlap, currently known only from Panay Island, the Philippines. The L. aureus complex can be defined by the following combination of characters: mouth protruding forward, not downward; small but sharp conical teeth uniserially on jaws; a black line between lower margin of eye and lower jaw articulation; and lateral line incomplete, ending below posterior part of dorsal fin base or on anterior caudal peduncle. Leiognathus hataii differs from both L. aureus and L. panayensis in having a large dark blotch below the spinous dorsal fin base and fewer counts of scales (lateral line scales 50–58 vs. 64–85 in the latter two species; scales above lateral line 7–10 vs. 12–18; scales below lateral line 22–26 vs. 30–41). Leiognathus panayensis is distinguished from L. aureus in having a deeper body (41–51% SL vs. 35–45% SL in the latter), long posterior limb of maxilla (21–25% HL vs. 15–23% HL), wholly scaled belly (vs. naked along preanal median keel), and a dark blotch on nape (vs. absent).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41594/1/10228_2003_Article_160.pd

Disease development

Disease 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 prevent massive losses by timely implementation of remedial measures

Fish health research at SEAFDEC/AQD

Fish pathology as a discipline was of relatively minor importance in the early years of SEAFDEC/AQD because technologies for producing aquaculture commodities were still being developed and high-density fish rearing activities were minimal. With fast adaptation of technologies developed locally and elsewhere and their modification to suit industry needs, disease problems started to occur. Disease develops through the interaction of three important factors: the host, the pathogen or disease agent, and the environment. In most high-density aquaculture rearing units, the environment exerts pressure on the host and favors the pathogen. When the host's defenses are overwhelmed, a disease condition is created which may result in death. Mortalities are often equated to economic losses, and research in fish diseases then becomes significant. Research has the ultimate aim of preventing disease occurrence