Various physical properties (viscosity, fluidity, surface tension and specific gravity) have been determined for muscle lipids of Ophicephalus striatus and Clarias batrachus. Results are presented and the methods used in determination noted. The physical parameters studied are found to be species-specific

Ishraq, A.

Jafri, A.K.

Mustafa, S.

Aquatic Commons

NOTE: II 
SOME PHYSICAL PROPERTIES OF THE MUSCLE LIPID OF 
TWO FRESHWATER TELEOSTS, OPHICEPHALUS STRIATUS 
(BLOCH,) AND CLARJAS BATRACHUS (UNN.) 
Though there is a considerable body 
of literature on the chemical qualities of 
fish lipids (Brocklesby, 1941; Lovern, 
1964; Ackman and Eaton, 1966; 1970; 
Ackman eta!., 1967; Addison et al., 1969; 
Malins and Wekell, 1969), information 
on the physical properties of the lipids 
of freshwater fishes is almost lacking. 
The present work is intended to report 
some important physical properties like 
specific gravity, viscosity, fluidity and 
surface tension of the muscle lip:d of two 
common Indian teleosts, namely Ophice-
phalus striatus (Bloch ), a freshwater murrel, 
and Clarias batrachus (Linn.), a freshwater 
cat-fish. 
The evaluation of the interspecific 
differences in these properties has been 
one of the interesting results of the pre-
sent study. 
Ophicephalus striatus of the size range 
380 - 520 mm. and Clarius batrachus of 
180 - 260 mm. were obtained live from the 
local fish market. The muscle lipid was 
extracted using a soxhlet extractor. 
The specific gravity of the .lipid was 
estimated by the method as given in the 
A. 0. A. C. (1960). The viscosity was 
determined with an OstwalJ Viscometer 
using the following equation: 
VoL 13 No. 1 1976 
dl tl 
fJ - dw tw 
where, 1J is the coefficient of viscosity 
of the lipid 
dl is the density of lipid (g/cc), 
dw is the density of water (gfcc), 
tl is the time of descent of lipid (sec.), 
and tw is the time of descent of water (sec.). 
The fluidity (if>) of the lipid was 
determined as the reciprocal of the coem 
fficient of viscosity, 
1 
1J 
The surface tension C\) of the lipid 
was estimated by the capillary-height 
method using the following equation: 
1 
-2- r.h.d.g. 
where, r is the radius of the capillary (em), 
h is the height to which the lipid 
ascended (em), 
d is the density of the lipid 
(g/cc), and 
g is the acceleration due to 
gravity (981 em. per sec.z) 
73 
Some pfl!)sical ]Jro)ledies of tfie muscle lipid of tmo [l·esfitvater teleosts 
TABLE I 
Physical properties of the muscle lipid of 0. saiatus and C. batrachus 
Specific 
gravity 
Viscosity 
dynes/ em 2 ;unit 
vebcity 
gradient 
Fluidity 
dynes/em 2junit 
velocity 
gradient 
Surface tension 
dynesjcm.~ 
Oplzicephalus striatus O.R94 
C larius bat raclws 0 947 
The values of specific gravity, visco-
sity, fluidity and surface tension of the 
muscle lipid of Ophicephalus striatus and 
Clarius batrachus have been given in 
Table I. · It may be evident from the 
Table that the specific gravity of the muscle 
lipid was higher in the cat-fish, C. batrachus 
than in the murre], 0. striatus. The 
specific gravity of the lipid of the two 
species was, however, lower than that of 
the water and this might be of advantage 
to the fish in its active movement in 
water. It was taken as established fact 
that like any liquid, the lipid also con-
sisted of a number of molecular layers 
arranged one over the other. The move-
ment of these different molecular layers 
relative to one another, was opposed by 
the internal friction or the viscosity of 
the lipid. The force per unit area requ-
ired to maintain unit difference of velocity 
between each _set of two parallel layers 
in the lipid, one centimetre apart, as 
expressed by the coefficient of viscosity, 
was found to be higher in C. batrachus 
as compared to that in 0. striatus. 
74 
5.190 0.192 12.058 
7.576 0.131 25.083 
As was evident from tte reciprocal 
relationship between the fluidity and 
coefficient of viscosity, the fluidity of the 
muscle lipid of 0. strtatus was higher-
than that of C. batrachus. 
The surface tension of any liquid, 
and so also of the lipid has been known 
to be the seat of a special force as a 
result of which the molecules in the sur-
face were bound together, forming a 
stretched layer tending to compress the 
molecules below to the sma:lest possible 
volume. This force in dynes acting upon 
a line of 1.0 em. length of the surface 
of the lipid, as expressed by the surface 
tension, was found to be greater in the 
muscle lipid of C. batrachus as compared 
to that of 0. striatus. 
Tt was, therefore, evident that the 
specific gravity, viscosity, fluidity and 
surface tension of the muscle lipid of fishes 
are species specific. 
We thank Prof. S. M. Alam, Head 
' 
Fish. Techno!. 
Some pftysical properties of tf?te muscle lipid of two fresfzwate.,. fisli.es. 
Department of Zoology, Aligarh Muslim 
University, Aligarh, for encouragement 
and providing research facilities. The 
last two authors are grateful to the 
Council of Scientific and Industrial Rese-
arch, New Delhi, for the award of research 
fellowship. 
REFERENCES 
Ackman, R. G. and C. A. Eaton. I 966. 
J. Fish. Res. Bd Canada., 23: 991. 
Ackman, R. G. and C. A. Eaton. 1970. 
J Fish. Res. Bd Canada , 27 : 1669. 
Acknnn, R. G., C A Eaton & P. J. Ke. 
1967. J. Fish. Res. Bd Canada. 
24: 2563. 
Section of Ichthyology & Fisheries, 
Department of Zoology, 
Aligarh Muslim University, 
Aligarh, India. 
Addison, R. F .. ·R. G. Ackman and J. 
Ringley. 1969. J. Fish. Res. Bd 
Canada., 26: 1577. 
A. 0. A. C., 1970. Association of Official 
Agricultural Chemists,. 9th edn., 
Washingcon. 
Brocklesby, H. N. 1941. Fish. Res. Bd 
Canada Bull., 59 : 442. 
Lovern, J. A. 1964. Oceanogr. mar. Biol. 
l : 169. 
Malins, D. C. and J. C. Wekkel. 1969 
The lipid biochemistry of marine 
organism. In "Progress in the Chemi-
stry of fats and other lipids" (R. T. 
Holman edn.) Pergamon Press, Oxford, 
*A. K. Jafri, 
Saleem Mustafa, 
Ishraq Ahmad. 
* Present address: Department of Biology, 
University of Mosul, Mosul, 
College of Science, 
Iraq. 
VoL 13 No. 1 1976 75 


Some physical properties of the muscle lipid of two freshwater teleosts, Ophicephalus striatus (Bloch.) and Clarias batrachus (Linn.)

http://aquaticcommons.org/18305/1/FT13.1_073.pdf

Some physical properties of the muscle lipid of two freshwater teleosts, Ophicephalus striatus (Bloch.) and Clarias batrachus (Linn.)

Abstract

Similar works

Full text

Available Versions

Aquatic Commons