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)

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

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

博士学位論文要

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

Polarized X-ray-emission Studies of Methyl Chloride and the Chlorofluoromethanes

A new technique sensitive to molecular orientation and geometry, and based on measuring the polarization of x-ray emission, has been applied to the Cl-containing molecules methyl chloride (CH3Cl) and the chlorofluoromethanes (CF3Cl, CF2Cl2, and CFCl3) in the gas phase. Upon selective excitation using monochromatic synchrotron radiation in the Cl K-edge (Cl 1s) near-threshold region, polarization-selective x-ray emission studies reveal highly polarized molecular valence x-ray fluorescence for all four molecules. The degree and the orientation of the polarized emission are observed to be sensitive to the incident excitation energy near the Cl Kedge. In some cases, the polarization direction for x-ray emission reverses for small changes in incident excitation energy (a few eV). It is shown that the polarized x-ray emission technique can be used to infer, directly from experiment, symmetries of occupied and unoccupied valence molecular orbitals, an- isotropies in absorption and emission, and orientational and geometrical information. It is suggested that the x-ray polarized-fluorescence phenomenon, reported here for simple molecules, can be used as a new approach to study more complicated systems in a variety of environments

Molecular-orbital Studies Via Satellite-free X-ray Fluorescence: Cl-K Absorption and K–Valence-level Emission Spectra of Chlorofluoromethanes

X-ray absorption and emission measurements in the vicinity of the chlorine K edge of the three chlorofluoromethanes have been made using monochromatic synchrotron radiation as the source of excitation. By selectively tuning the incident radiation to just above the Cl 1s single-electron ionization threshold for each molecule, less complex x-ray-emission spectra are obtained. This reduction in complexity is attributed to the elimination of multielectron transitions in the Cl K shell, which commonly produce satellite features in x-ray emission. The resulting satellite-free x-ray-emission spectra exhibit peaks due only to electrons in valence molecular orbitals filling a single Cl 1s vacancy. These simplified emission spectra and the associated x-ray absorption spectra are modeled using straightforward procedures and compared with semiempirical ground-state molecular-orbital calculations. Good agreement is observed between the present experimental and theoretical results for valence-orbital energies and those obtained from ultraviolet photoemission, and between relative radiative yields determined both experimentally and theoretically in this work

In vitro effects of fungicides on the fungus Haliphthoros philippinensis

Pure cultures of Haliphthoros philippinensis, isolated from infected Penaeus monodon larvae, were exposed for 24 hours to varying concentrations of antifungal agents. The efficiency of each agent to inhibit sporulation and mycelial growth was measured. Effects on P. monodon eggs and larvae were also investigated. It is concluded that preliminary bioassay of larval tolerance to the suggested effective doses should always be made prior to prophylaxix or therapeutic applications

In-vitro effect of fungicides on hyphal growth and sporogenesis of Lagenidium sp. isolated from Penaeus monodon larvae and Scylla serrata eggs

The sensitivity of Lagenidium, isolated from Penaeus monodon, Scylla serrata , to 34 antimycotics was determined. Effects on the development of vesicles, zoospores and mycelial growth were evaluated. Although mycoidal levels of the chemicals tested will be ideal for lethal treatment on control of the fungus, the high dose required may be lethal to the host, thus the use of mycostatic concentrations is more practical. Treatments of rearing water containing larvae, adult shrimps or crabs should be done only after preliminary tolerance experiments using at least the mycostatic dose prove to be safe for the hosts. Mycocidal doses can be used for determining disinfection doses of equipment and facilities used in rearing procedures as well as for destroying batches of infected larvae