Saltwater fish

A relatively small number of studies have reported on the effects of cumene on plants, fish, and other organisms. Studies of the effects of cumene on fresh and saltwater fish indicate the lowest reported toxic concentration (LC q) for fishes was 20 to 30 mg/L (18). The solubiUty of cumene is about 50 mg/L (19). Among invertebrates, the lowest reported concentration that was toxic to test organisms was 0.012 mg/L after 18 hours (20). The only available data on the effect of cumene on aquatic plants indicate that the photosynthesis of several species was inhibited at concentrations from 9 to 21 mg/L (19). 

C12-0100. Saltwater fish have blood that is isotonic with seawater, which freezes at -1.96 ° C. What is the osmotic pressure of fish blood at 15 °C ... 

Hansen DJ, Schimmel SC, Forester J. 1977. Endrin Effects on the entire life-cycle of saltwater fish, Cyprinodon variegatus. J Toxicol Environ Health 3 721-733. 

Dietary source required if insufficient exposure to UV light. Vitamin 1% is found in saltwater fish (salmon) and egg yolks. 

Fig. 18. Plot on the discriminant functions of LDA. 3 categories (saltwater fish, freshwater fish, cephalopoda). 10 variables (fatty acids). (Adapted from Ref. after correction)...

The relative amounts of the enzyme in kidneys of fish from different habitats have been measured (105) (Table IX). Particularly interesting is the finding that the mutarotase levels in kidneys of freshwater fish are always higher than those in saltwater fish, averaging six times greater. This extends an earlier observation by Keston that the enzyme was present in low levels in the aglomerular toadfish kidney (68). 

Suggest a reason why saltwater fish die when they are suddenly transferred to a freshwater aquarium. 

Although the term vitamin A has been used to denote specific chemical compounds, such as retinol or its esters, this term now is used more as a generic descriptor for compounds that exhibit the biological properties of retinol. Retinoid refers to the chemical entity retinol or other closely related naturally occurring derivatives. Retinoids also include structurally related synthetic analogues, which need not have retinol-like (vitamin A) activity. The structural formulas for the vitamin A family of retinoids are shown in Figure 66.3. Retinol (vitamin Aj), a primary alcohol, is present in esterihed form in the tissues of animals and saltwater fish, mainly in the liver. A closely related compound, 3-dehydroretinol (vitamin A2), is obtained from the tissues of freshwater fish and usually occurs mixed with retinol. 

Freshwater fish tests are generally conducted on bluegill, a warm water fish, and rainbow trout, a cold water fish. Catfish, fathead minnows and sometimes carp are also used depending on the expected route of exposure. Sheepshead minnow is the commonly used saltwater fish. 

A series of alcohols (C4 - Cll) were identified in the tail meat. Odor threshold concentrations were generally higher for alcohols than the aldehyde counterparts. Except for 1-pentanol, the remainder of alcohol peaks were very small and might not be significant in overall arctna of boiled crayfish tail meat. Josephson et al. (23-25) found l-octen-3-ol, an enzymatic reaction product derived from lipids, to be one of the volatile ccxnponents widely distributed in fresh and saltwater fish. The compound 2-butoxyethanol identified in crayfish tail meat (3) has been reported in beef products (26-27). GC aroma perception of standard 2-butoxyethanol gave a spicy and woody note, hence this compound could be an important flavor component of the boiled crayfish tail meat. 

The iodine content of a variety of foods in East Africa was measured by ICP-MS [276]. Samples were dried and homogenized prior to dissolution. Tellurium was used as an internal standard. Only saltwater fish were found to be a sufficient dietary source of iodine. 

Iodine is not present in sufficient amounts in the diet in several areas of the world an iodine deficiency results in goiter. The addition of iodine to table salt has been extremely effective in reducing the incidence of goiter. The iodine content of most foods is in the area of a few mg/100 g and is subject to great local variations. Fish and shellfish have higher levels. Saltwater fish have levels of about 50 to 150 mg/100 g and shellfish may have levels as high as 400 mg/100 g. 

Maintaining the proper saline (salt) concentration is important to the health of saltwater fish. 

The US Environmental Protection Agency ECOTOX database has very few records for decane. An acute (48-96 h) no-observed-effect concentration of 500 mgl was recorded for the sheepshead minnow (saltwater fish). Acute effects (48 h exposure) on the water flea (Daphnia magna LC50) ranged from 1.3 to 29mgl (freshwater cladocercan). 

Hair. Scalp hair is another primary indicator used to assess methylmercury exposure, because the methylmercury is incorporated into the hair at the hair follicle in proportion to its content in the blood (EPA 1996d). The typical hair-to-blood ratio in humans has been estimated to be about 250 1 expressed as g Hg/g hair to mg Hg/L blood, but some difficulties in measurements, inter-individual variation in body burden, differences in hair growth rates, and variations in fresh and saltwater fish intake have led to varying estimates (Birke et al. 1972 Skerfving 1974). Once incorporated into the hair strand, the methylmercury is stable and gives a longitudinal history of blood methylmercury levels (WHO 1990). 

Infants and developing fetuses may be exposed to methylmercury if their mothers consume certain methylmercury-contaminated fish, shellfish, or wildlife species from contaminated waters prior to their pregnancy, during their pregnancy, or while nursing. Older children also may be exposed to methylmercury by eating contaminated fish and wildlife species. Certain states, Native American tribes, and U.S. Territories have issued fish and wildlife advisories for mercury in fresh water, estuarine, and saltwater fish and in freshwater turtles (see Section 5.7). 

Six-carbon volatile alcohols and aldehydes have been found in all freshwater fish surveyed (23-24). However, these compounds have not been found in either salmon residing in saltwater (unpublished data) or in oysters (26). Hexanal has been found in modestly fresh (5-6 days old) saltwater fish (24), but its formation may be the result of autoxldation rather than via enzyme-mediated reactions. Thus, data for the occurrence of hexanal in freshly harvested saltwater fish remains to be developed. Hexanal and (E)-2-hexenal contribute coarse, green-plant-like, aldehydic aroma notes to freshly harvested finfish where their aroma dominates the overall odors within seconds after the death of the fish. (Z)-3-Hexen-l-ol contributes a clean, green-grass-like aroma note. Hexanal always occurs in substantially greater abundance than 1-hexanol in fish. 

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