This is at the extreme margin of relevancy for pond owners and is simply passing on info in that context. If you are feeding BG , HSB or LMB (carnivores) as opposed to CC , carp , tilapia or shads etc (omnivores or herbivores) then lipids from fish or natural diets (eaten) provide the ideal lipid structure for rapid temp (cold water) change survival. Pellets do not provided that as well as natural foods except that pellets with substantial quality fish meal in high % come close to providing that. Here is some text from a study about the matter using HSB. Same concept for other similar fish.

Cold Tolerance and Fatty Acid Composition of
Striped Bass, White Bass, and Their Hybrids
ANITA M. KELLY*1 AND CHRISTOPHER C. KOHLER

Fish fed the prepared diet also died at higher temperatures
than fish fed the natural diet (Figure 1).
Striped bass fed the prepared diet had the highest
lower incipient lethal temperature (LILT; 5.98C),
followed by palmetto bass (4.88C), sunshine bass
(2.58C), and white bass (1.98C). Fish fed the natural
diet had considerably lower LILT, with all taxa
being near 0.08C, except palmetto bass, which had
a LILT of 1.88C. Palmetto bass was the only taxon
in which disease became a problem at lower temperatures.

The phospholipid fatty acid composition
for the muscle lipids for all four taxa were reflective
of the diets they received (i.e., the natural diet
had a higher percentage of unsaturated fatty acids,
as did the muscle tissue of the fish that consumed
the natural diet;

We demonstrated that diet-induced muscle fatty
acid composition directly affects cold tolerance of
striped bass, white bass, and their hybrids. Fish
fed fathead minnows had U : S fatty acid ratios 10–
25% higher than fish fed a prepared diet. When
subjected to a simulated cold front, all groups of
fish fed the prepared diet suffered high mortality
(50–90%) whereas the groups fed the natural diet
experienced zero mortalities.

Diets influence the fatty acid composition in several
species of fish (Henderson and Tocher 1987;
Lovell 1989; Seo et al. 1994), and the ability of a
fish to alter its lipid composition when placed in
colder water is one factor that determines survival.
For example, summer harvest syndrome is an anomaly
seen in goldfish Carassius auratus when they
are harvested in the summer and placed in tanks
containing water that is colder than the pond water
(Mitchell 1990). The death of these fish is thought
to be a result of the fat that the goldfish consume
or produce (Mitchell 1990). Goldfish with high concentrations
of saturated body fat are less tolerant of
temperature change than fish with high concentrations
of unsaturated body fat. Similarly, rainbow
trout Oncorhynhcus mykiss that have been fed diets
high in saturated fats stiffen and die when placed
in cold water (Mitchell 1990). In these fish, the fat
apparently hardens in the colder water, causing the
fat-impregnated muscles to stiffen and the fish to
become exhausted and lose movement.
The amount of unsaturated fatty acids in the
muscle is believed to affect a fish’s ability to tolerate
lower temperatures (Hoar and Dorchester
1949; Hoar and Cottle 1952a, 1952b). In general,
the tissue temperature of fish is within 18C of the
ambient water temperature (Carey et al. 1971;
Reynolds et al. 1976). Physiologically, fish are affected
by variations in water temperature in two
ways (Hochachka and Somero 1984). First, temperature
determines the rate of chemical reactions,
and secondly, temperature dictates the point of
equilibrium between the formation and disruption
of the macromolecular structures in biological
membranes. Structural flexibility, therefore, is a
requirement for integrity of biological membranes
(Hazel 1993). Cold temperatures constrain this
flexibility and, as a result, stabilize less active conformations.
The rate of increase in the ability of
fish to tolerate higher temperatures usually requires
less than 24 h at temperatures above 208C,
whereas the gain in resistance to lower temperatures
is a much slower process, requiring up to 20
d in some species (Doudoroff 1942; Brett 1944).
The rate of resistance to lower temperatures is governed
in part by the rate of metabolism, which is
depressed at lower environmental temperatures.
The simulated cold front in this study resulted in
higher mortalities in the striped bass and the palmetto
bass when compared with the white bass
and the sunshine bass. Although no studies have
been conducted to determine the amount of time
required to gain resistance to lower temperatures
in striped bass, white bass, or their hybrids, this
study suggests that when these fish receive a natural
diet they are well suited to sudden changes in
water temperature. However, when these fish are
fed a prepared diet, this ability to adapt to sudden decreases in water temperature is less apparent.
This suggests that diet influences the fish’s ability
to adapt to sudden water changes.

Last edited by ewest; 05/08/18 01:12 PM.