In fishes

A USDA report indicates that between 1967 and 1988, butter consumption remained stable at 2 kg per capita, margarine dropped from 5.1 to 4.7 kg, and measured total fat intake per day dropped from 84.6 to 73.3 g (14). This study also projects that the reduced consumption of tropical oils is only temporary and will return to former use levels, possibly even higher. One reason for this projected rise in tropical oil consumption is the knowledge of the beneficial effects of medium-chain length acids high in lauric oils. There is a keen interest in omega-3 fatty acids, as well as linoleic acid, contained in fish oils. 

PVA fiber ropes are widely used in fishing and on ships, because of excellent weather resistance, coiling property, ease of handling, twist stabihty, etc. For this purpose spun yams obtained directly from tow by the Pedok spinning system are used. 

In general, nonconventional protein foods must be competitive with conventional plant and animal protein sources on the bases of cost delivered to the consumer, nutritional value to humans or animals, functional value in foods, sensory quality, and social and cultural acceptability. Also, requirements of regulatory agencies in different countries for freedom from toxins or toxic residues in single-cell protein products, toxic glycosides in leaf protein products, pathogenic microorganisms, heavy metals and toxins in fish protein concentrates, or inhibitory or toxic peptide components in synthetic peptides must be met before new nonconventional food or feed protein products can be marketed. 

Exposure. The exposure of humans and animals to mercury from the general environment occurs mainly by inhalation and ingestion of terrestrial and aquatic food chain items. Pish generally rank the highest (10—300 ng/g) in food chain concentrations of mercury. Swordfish and pike may frequently exceed 1 p.g/g (27). Most of the mercury in fish is methyl mercury [593-74-8]. Worldwide, the estimated average intake of total dietary mercury is 5—10 p-g/d in Europe, Russia, and Canada, 20 pg/d in the United States, and 40—80 pg/d in Japan (27). 

According to NAS, "Fish-eating birds should be protected if mercury levels in fish do not exceed 0.5 mg/g."... 

Nifurprinol. 6-[2-(5-Nitro-2-furanyl)ethenyl]-2-pyridine methanol, is prepared from 5-nitro-2-furancarboxaldehyde and 6-methyl-2-pyridine methanol (48). The product has been used as an antibacterial in fish diseases. 

Because of the time and expense involved, biological assays are used primarily for research purposes. The first chemical method for assaying L-ascorbic acid was the titration with 2,6-dichlorophenolindophenol solution (76). This method is not appHcable in the presence of a variety of interfering substances, eg, reduced metal ions, sulfites, tannins, or colored dyes. This 2,6-dichlorophenolindophenol method and other chemical and physiochemical methods are based on the reducing character of L-ascorbic acid (77). Colorimetric reactions with metal ions as weU as other redox systems, eg, potassium hexacyanoferrate(III), methylene blue, chloramine, etc, have been used for the assay, but they are unspecific because of interferences from a large number of reducing substances contained in foods and natural products (78). These methods have been used extensively in fish research (79). A specific photometric method for the assay of vitamin C in biological samples is based on the oxidation of ascorbic acid to dehydroascorbic acid with 2,4-dinitrophenylhydrazine (80). In the microfluorometric method, ascorbic acid is oxidized to dehydroascorbic acid in the presence of charcoal. The oxidized form is reacted with o-phenylenediamine to produce a fluorescent compound that is detected with an excitation maximum of ca 350 nm and an emission maximum of ca 430 nm (81). 

Vitamin A [79-80-1] (6) is stmcturaHy similar to vitamin A [68-26-8] and is also found in fish oils. This compound is important biologically for fish and other lower animals. Interestingly, tadpoles require vitamin A but after metamorphosis require vitamin A (8). 

Casoron-IOG) diquat dibromide [2764-72-9 C H Br N algicide and herbicide 0.1 ppm in fish EPA proposed a... 

The identification of PCB residues in fish, wildlife, and human tissues has been reported since the 1970s (9—13,20—26). The results of these analytical studies led to the ultimate ban on further use and production of these compounds. The precise composition of PCB extracts from biota samples is highly variable and depends, in part, on the specific analyte and the commercial PCB preparations associated with a contaminated area (14). PCBs found in a composite human milk sample from Michigan (26) were highly complex, and the congener composition and their relative concentrations did not resemble any of the commercial PCB preparations. This fact raises obvious problems with regard to the ha2ard assessment of PCB mixtures (27). 

Copper has been employed as a bactericide, moUuscicide, and fungicide for a long time and is of importance in the control of schistosomiasis (see also Antiparasitic AGENTS, ANTHELMINTICS FUNGICIDES, AGRICULTURAL). Addition of copper to lake water acts as an efficient deterrent to transmittal of the disease by eliminating snails that act as hosts for the responsible parasite. Copper is commonly utilized at ca 0.1 mg/L as an algicide. In fresh water, acute toxicosis in fish is unusual if the copper concentration is below 0.025 mg/L (70) (see Poisons, economic). 

Alloxan (1003) has been observed in the mucus associated with dysentery and it was the very first pyrimidine made synthetically when Brugnatelli oxidized uric acid in 1818. Alloxan has an interesting diabetogenic action which appears to be associated with removal of essential zinc from insulin by chelation. Such permanent diabetes may be induced in fish, dogs, cats, sheep, some birds, monkeys and other creatures, but not in man, owls or guinea-pigs certain pyrimidines related to alloxan show some such activity. 

The elemental composition of the fish otoliths is a potential source of the useful information to recreate environment history of the individual fish in some of the species. In-depth study of the chemical composition of the otolith center (formed eaidy in fish life) and otolith edge (formed later in fish life) ensures chronological and environmental information stored in the otoliths [1]. This infoiTnation may be achieved by X-ray electron probe microanalysis (EPMA). EPMA is the analytical method to determine the elemental composition of different otolith s parts, their sizes varying from ten up to some tens of microns. 

EVALUATION OF POLYCHLORINATED BIPHENYLS AND ORGANOCHLORINE PESTICIDES CONTENT IN FISH TISSUE OF DNIEPER RIVER BASIN BY GC/MS... 

The OECD has been very active in the development of a concensus on tests for endocrine disruption in fish, including selection of enhancements to guidelines... 

D. E. Kime, Endocrine Disruption in Fish, Kluwer, Boston, 1998. 

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