Cold-water fishes

Antifreeze Certain plasma proteins of cold water fish... 

Omega-3 fatty acids (eicosapentaenoic acid and docosa-hexaenoic acid), the predominant fatty acids in the oil of cold-water fish, lower triglycerides by as much as 35% when taken in large amounts. Fish oil supplements may be useful for patients with high triglycerides despite diet, alcohol restriction, and fibrate therapy. This effect may be modulated thru PPAR-a and a reduction in apolipoprotein B-100 secretion. Omega-3 fatty acids reduce platelet aggregation and have... 

Human disease associated with eating fish not previously identified with a particular toxin has also been reported. One example is saxitoxin poisoning associated with eating pulfer fish caught in Florida. Another example involves CFP. Ciguatera has not historically been associated with cold-water fish, but Dinubile and Hokama (1995) reported a case of CFP in a woman who had eaten farm-raised salmon. 

Cold water fish gelatin (Sigma, St. Louis, MO) Warm in 37°C water bath to liquefy prepare dilute solutions just prior to use keep stock bottle at 4°C. 

In order to stabilize the probes, add warmed (37°C) cold-water fish gelatin to give a final concentration of 1%. 

Repeat the centrifugation. Remove and discard the supernatant, and resuspend the soft pellet in 1-2 mL TBS containing 1% cold-water fish gelatin. Dialyze for 1 h at room temperature against TBS. 

Dilute the resulting preparation with TBS containing 1% cold-water fish gelatin, and store in the refrigerator. 

Land animals exploit the odorsphere, the world of vapors around them. In any given locale, they move in an odorscape, a landscape of volatiles. Even in fish we speak of odors because neurophysiologically the olfactory system is involved, even though water-soluble stimulants are not necessarily volatile. We expect vertebrates to have taken advantage evolutionarily of the physicochemical characteristics of their environment first to select and then to optimize chemical communication. The chemical communication system of a cold-water fish differs vastly from that of a tropical bat. Despite similar biological functions, each system has been shaped by, and is adapted to, a distinct set of environmental circumstances. 

DeVries, A.L. (1983). Antifreeze peptides and glycopeptides in cold water fishes. Annual Review of Physiology 45, 245-60. 

Sources are liver, salmon, and other cold-water fish, egg yolks, and fortified milk and dairy products. Beta Carotene... 

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. 

The two processes proceed together as the seasonal and age-induced changes in protein add up. The ratio between oscillating and progressive changes in protein is markedly higher in warm-water fish than in cold-water fish, so that the latter expend less protein in the winter compared with the former. 

In some species, like the cold-water fish of the Black Sea, protein and lipid accumulation may occur together, while in fish which prefer warmer water in the same sea, such as anchovy and horse-mackerel, they do not. Both the degree and duration of such concordance are important in the adaptation of fish. 

The activity of alkaline phosphatase in fish scales is relevant to the study of the biochemical characteristics of production (Senkevich, 1967 red mullet, round goby). This enzyme promotes calcification of bones and scales, and its activity correlates well with the linear growth of the fish (Figure 55), so it is most intense during the warm season. Data from cold-water fish are not available. 

It should be borne in mind that the lipid index cannot characterize the food supply over the whole annual cycle, but only that in the period when lipids are accumulated rather than consumed. For warm-water fish of the southern European seas, this is the summer and autumn, while for cold-water fish such as the Black Sea and Mediteranean sprat, it is spring and summer. The food... 

In fish which require cold water (sprat and whiting), the annual rhythms are not nearly so well defined. Their preferred temperature zone is in deep water, where the temperature is relatively stable throughout the year. The temperature of the regions of the Black Sea inhabited by warm-water fish may vary by as much as 10-15° over the year, but the habitat of cold-water fish varies by only 3-5°. The latter fish have not only a smaller metabolic variation throughout the year, but also a higher consumption of food in winter (sprats consume 7.3% of their body weight daily at that time) than that of the species requiring warm water. 

In the Black Sea, the production of protein and accumulation of lipid occur simultaneously in cold-water fish, while in the warm-water fish the activities are separated. Pickerel, which are intermediate as regards temperature preference, display similarities to both other forms. Like the warm-water fish, the major part of production occurs during the warm season, although the amplitude of the biological rhythms is not as pronounced. Like the cold-water whiting, the pickerel use protein, not lipid, as a main reserve. 

Methoxychlor is degraded in vivo by 0-dealkylation and excreted as mono-and bis-phenols. It is much less environmentally persistent also much less toxic to rats (oral LD q> 6000 mg/Kg compared with LD q 118 mg/Kg for DDT Metcalf, ref. 16). However, methoxychlor toxicity in fish approaches that of DDT, and in cold water fish, e.g., Atlantic salmon, it can accumulate to excessive levels. Although much less toxic in mammals than DDT it is similar in its estrogenic action. Methylchlor is less toxic to fish than methoxychlor, but also rather ineffectual as an insecticide. Comparison of the persistence characteristics of the methyl and methoxy analogs of DDT shows the microsomal side chain oxidation of the alkyl group to be more efficient than microsomal 0-dealkylation. 

Enzymes are proteins that catalyze reactions. Thousands of enzymes have been classified and there is no clear limit as to the number that exists in nature or that can be created artificially. Enzymes have one or more catalytic sites that are similar in principle to the active sites on a solid catalyst that are discussed in Chapter 10, but there are major differences in the nature of the sites and in the nature of the reactions they catalyze. Mass transport to the active site of an enzyme is usually done in the liquid phase. Reaction rates in moles per volume per time are several orders of magnitude lower than rates typical of solid-catalyzed gas reactions. Optimal temperatures for enzymatic reactions span the range typical of living organisms, from about 4°C for cold-water fish, to about 40°C for birds and mammals, to over 100°C for thermophilic bacteria. Enzymatic reactions require very specific molecular orientations before they can proceed. As compensation for the lower reaction rates, enzymatic reactions are highly selective. They often require specific stereoisomers as the reactant (termed the substrate in the jargon of biochemistry) and can generate stereospecific products. Enzymes are subject to inhibition and deactivation like other forms of catalysis. 

DeVries, A.L., and C.-H.C. Cheng (1992). The role of antifreeze glycopeptides and peptides in the survival of cold-water fishes. In Water and Life, pp. 301-315, ed. G.N. Somero, C.B. Osmond, and C.L. Bolis. Berlin Springer-Verlag. 

Cold-water fish like salmon are rich in omega-3 fatty acid.s, which have a double bond three carbons in from the noncarboxyl end of the chain and have been shown to lower blood cholesterol levels. Draw the structure of 5,8,1 l,i4,17-eicosapentaeiioic acid, a common example. (Eicosanc = C20H42-)... 

The feeding of soybean lecithin to cold-water fish and cold-water cmstaceans— as a source of choline, inositol, ethanolamine, and PUFA—has been promoted in recent years. Levels as high as 7-8% of diet dry weight have been recommended (40, 41). 

---