Fishing experiments were conducted with buffalo horn, wooden and galvanised iron jigs of different lengths and weights rigged in troll lines. It was observed that jigs with 12 cm length and 60 g weight were superior to others in luring seer fish. Fish head jigs of 60 g weight showed a higher efficiency index than those of 50 and 70 g tried in these studies

Manoharadoss, R.S.

Subramonia Pillai, N.

Sulochanan, P.

Aquatic Commons

FO 
fFE 
N. SUBRAMONIA PILLAlf, R. S. MANOHARADOSS AND P. SULOCHANAN 
Central Institute of Fisheries Technology, Craft & Gear Wing, Cochin-5 
Fishing experiments were conducted with buffalo horn, wooden 
and galvanised iron jigs of different lengths and weights rigged in 
troll lines. It was observed that jigs with 12 em length and 60 g 
weight were superior to others in luring seer fish. Fish head jigs 
of 60 g weight showed a higher efficiency index than those of 
50 and 70 g tried in these studies. 
INTRODUCTION. 
Simplicity in construction and effect-
iveness in operation of troll lines with 
artificial lures (jigs) for the capture of 
predatory fishes such as seer, tunny, bara-
cuda etc have been emphasised by ear-
lier workers (Deshpande and Sivan, 1969, 
Subramonia PiUai et a!, 1971). A careful 
observation on the behaviour pattern of fish 
caught in troll lines indicate a certain degree 
of preferential bites to the different lures 
(Milne 1955; Sivan and Panikar, 1969). Si-
milarly, jigs with different dimensions and 
weights are likely to exert an influence 
on the catches, as on the one hand they 
would be apparently different in appearance 
and visibility and on the other there would 
be differences in the degree of sinking. Since 
investigations on these and similar aspects 
have not yet been conducted, studies were 
initiated with jigs of different physical 
specifications, thereby bringing about a 
further improvement in the luring effect of 
these jigs. The present communication 
deals with the results obtained on the 
studies conducted with buffalo horn and 
68 
wooden jigs having nine different specifi-
cations in each, galvanised iron jigs in 
six different specifications and fish head 
jigs in three different specifications. 
MATERIALS AND METHODS: 
The rigging of the gear imd mode of 
operations were similar to those described 
by Deshpande et a! (op cit). The brass 
BRASS SWIVEl; 
!]'.!:!: 
Wiight. !!Hh;m. 
Br~ald~ 
Stfl'il'ifitl'i.'~~ Kg. 
1 
FISHERY TECHNOLOGY 
'Pillai et al: Standardisation o/ speci~cations for different t?-olling lures. 
swivels used for the rigging of the lines 
were of uniform specification, the details 
of which are shown in Fig 1. The design 
details of 12.5 em long jig3 are as given 
by Subramonia Pillai et a! ~op cit). The 
details of nine different specifications of 
buffalo horn and wooden jigs, six diffe-
erent specifications of glavanised iron jigs 
and three different specifications of fish 
head jigs are given in Table 1. 
TABLE I SPECIFICATIONS OF JIGS 
Jigs Length: Weight of the jigs: g 
Buffalo horn 
Wooden 
Galvanised 
em. 
10.0 50, 
12.5 
15.0 
Same specifi-
cations as above 
60, 
-do-
-do-
70 
iron 12.5 
15.0 
Fish head type -
50, 60, 70 
-do-
-do-
The 10 em and 15 em long jigs 
(Fig 1 A) were fabricated on the basis 
of the design of 12.5 em jigs, by adjusting 
the different dimensions. 
For jigs of indenticallength, differences 
in weight were brought about by adding 
lead pieces at their lower surfaces. The 
galvanised iron jigs and fish head jigs 
were got fabricated in their specified weights. 
Initially a series of twelve valid ope-
rations were carried out with nine different 
specifications of buffalo horn jigs. Sub-
sequently, another series of twenty valid 
operations were carried out with six different 
specifications of buffalo horn jigs, elimi-
nating the three specifications of jigs of 
10 em length which were found to be less 
effective during the initial triaL Wooden 
jigs were operated in nine specifications 
BOFFALO HORN J!GS 
·r\ 0 
~w~ N , __ , 
I 
3 Dio 
Ali Dimensions ore in mm. 
-----~·---·--------------------11 
VoL IX No 1 1972 
'Pillai et al: .Standardisation of specifications (or different trolling lures. 
as in the first series of buffalo horn jigs. 
Seventeen valid operations were carried 
out with six different specifications of 
. galvanised iron jigs, in the same manner 
as the second series of buffalo horn jigs. 
In the case of fish head jigs, a series of 
nine valid operations were carried out 
using all the three specifications of weight. 
The arrangement of the different specifi-
cations of jigs for all operations were 
statistically designed in order to minimise 
the effect of chance factor. 
RESULTS: 
The results of the first series of ope-
rations with all nine different specifications 
and second series with six specifications 
of buffalo horn jigs are given in Table II. 
TABLE U CATCHES BY DIFFERENT SPECIFICATIONS OF BUFFALO HORN JIGS 
Specifications of jigs No. of fish caught Weight: % of the to tal catch by number 
Length: kg. For each Total for 
em. Weight: g Jig each length 
group of jigs 
50 7 6.6 
10.0 60 8 7.6 23.7 
70 10 9.5 
,_. 
r:/J 50 10 9.5 ,.... 
Ul 12.5 60 26 24.8 45.8 
(D 70 12 ll.5 .-; 
...... 
(D 
Cfl 50 8 7.6 
15.0 60 14 13.4 30.5 
70 10 9.5 
50 10 43.5 7.3 
N 12.5 60 46 191.5 33.8 51.5 l:i 
0... 70 14 60.0 10.4 
Ul 50 18 68.5 13.2 (D 
.-; 
(D" 15.0 60 28 131.5 20.6 48.5 r:/J 
70 20 91.5 14.7 
The catch details of the wooden jigs are shown in Table III· 
TABLE HI CATCH DETAILS OF WOODEN JIGS 
Specification of jigs No. of fish % of the total catch by number 
caught For each For each 
Length: em. Weight: g. Jig length group of jigs 
50 2 2.9 
10.0 60 6 8.8 22.0 
70 7 10.3 
50 3 4.4 
12.5 60 17 25.0 42.6 
70 9 13.2 
50 6 8.8 
15.0 60 11 16.2 35.3 
70 7 10.3 
70 FISHERY TECHNOLOGY 
Pillai et al: Standardisation of specifications [or different trolling lures. 
Table IV shows catch details of the galvanised iron jigs in six different specifications. 
TABLE IV CATCH DETAILS OF GAL VANISED IRON JIGS. 
Specifications of 
the jigs 
Length: em. Weight: g. 
No. of fish 
caught 
Weight of 
fish: kg. 
% of 
For each 
Jig 
the total catch 
For each length 
group of jigs 
-----------------------------------------------------12.5 50 12 
" 
60 62 
" 
70 15 
15.0 50 5 
" 
60 22 
" 
70 14 
Fig II shows the frequency of catch 
m the different specifications of the fish 
head jigs. 
140 
120 
"' iooo 
~ so 
0 Gt> 
0 
z 40 
20 
Cl'J 70c.:;!s 
Oh'fer~mt wo-tgM.:a Gf Jir.Dlll 
F!Q.2. NO. OF SEr£115 CtiUGMT 1tJ DIFFERENT SPECIF~ 
OF FISM MEAD JIG 
Table V shows the comparison of 
catch in different specifications of buffalo 
horn and wooden ji5s and buffalo horn 
and galvanised iron jigs separately. 
Source 
Total 
Blocks (ignoring 
treatments) 
Treatments 
(eliminating block) 
Error 
ss 
3.7145 
0.4447 
1.0929 
2.1769 
TABLE 
42.25 9.2 
181.00 47.7 68.4 
50.00 U.S 
. 14.50 3.9 
67.50 17.0 31.6 
35.25 10.7 
DISCUSSION: 
As evidenced from the results in 
Table II, buffalo horn jig of 12.5 em length 
having 60 g weight was superior to the 
other specifications of jigs, in catching seer. 
Of the total catch, the above jig landed 
24.8%, whereas the catch for the other 
specifications of jigs was more or less 
half or even less. Taking into conside-
ration the jigs of different length groups, 
irrespective of weights, the jigs of 12.5 em 
length landed 45.8% of the total catch 
(by number). In general, the jigs of 10 em 
length were found to be less effective. 
Table II also clearly reveals the superi-
ority of buffalo horn jigs of 12.5 em length 
having 60g weight by landing 33.8% of 
the total catch by number. 
The data were statistically analysed 
by taking into account the number of 
fishes caught in different specifications of 
jigs. The analysis of variance of the data 
is given in Table VI. 
VI 
DF 
71 
8 
52 
MS 
0.0404 
0.1366 
0.0418 
F 
21 
3.27* 
-----------------------------------------------::: Sigai:ficant at l% level 
VoL IX No 1 1972 
-....) 
N 
F:rj 
..... 
Vl ; 
...:! 
~ 
@ 
~ 
~ 
Specifica- ! Length: 
tion of 1 em jigs Weight: g 50 
Buffalo horn jigs 6.6 
Wooden jigs 2.9 
*Bnffalo horn jigs 
Galvanised iron jigs 
TABLE V 
CATCH INDICES IN PERCENTAGES OF THE TOTAL FOR THE DIFFERENT 
SPECIFICATIONS OF BUFFALO HORN, WOODEN AND 
GAL V ANISED IRON JIGS 
10.0 12.5 15.0 Total No. 
of fish 
60 70 50 60 70 50 60 70 caught 
-
7.6 9.5 9.5 24.8 11.5 7.6 13.4 9.5 105 
-
8.8 10.3 4.4 25 13.2 8.8 16.2 10.3 68 
-
7.3 33.8 10.4 13.2 20.6 14.7 136 
9.2 47.7 11.5 3.9 17.0 10.71 131 
* The second series of operation of B. H. jigs, 
No. of Catch/ days of 
opera- day 
tions 
20 5.2, ie; 5 
13 5.2, ie; 5 
16 8.5, ie; 8 
15 8.7, ie; 9 
---
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Pillai et al: {)tanclardisation of specifications for different trolling lures. 
From the above table, it follows that 
the treatment combinations are significant 
at 1% level. An examination of the ave-
rage of the treatment combination shows 
that the jigs with 12.5 em length and 60g 
weight catch more fish, compared to the 
other combinations, with the 15cm length and 
60g weight jigs coming next in effectiveness. 
Analysis of the weights of fish taken by 
each specification of jigs showed that even 
quantitatively the jigs with 12.5 em length 
and 60g weight catch more than the other 
combinations at 5% level of significance. 
Analysis of the data collected during the se-
cond cycle of operation (Table H) was done 
taking into consideration the weight of the 
fish caught in the six different combina-
tions of the jigs by the analysis of vari-
ance technique. (Table VII) 
TABLE 
Source ss 
Total 7516.58 
Between SIZeS 62.75 
Between weights 1088.64 
B::twcen operations 3287.58 
Size x weight 5.94 
Size x operation 600.21 
Weight x operation 1808.71 
Eroor 666.35 
their degree of effectiveness. However, it 
may be added in this connection that the 
durability of the wooden jig is much less 
compared to other types. 
Tabl IV shows comparative catching 
efficiency of different specifications of gal-
vanised iron jigs. It is clear that jigs with 
12.5 em length having 60 g weight are supe-
rior in their catching rate to the other spe-
cifications of jigs by landing 47.7% ofthe 
total catch. The catching rate of the other 
sp::cifications of jigs are comparatively 
poor except for the jigs having 15cm length 
and 60 g weight (17 .0%). 
The data on the weight of the fish 
were analysed using the analysis of vari-
ance technique after converting them into 
VII 
DF MS F 
101 
1 62.75 3.01 
2 592.52 26.06* 
16 205.47 9.81* 
2 2.97 0.14 
16 37.51 1.80 
32 56.52 2.71* 
32 20.82 
* Indicates significance ab l <>£. level. 
Significant difference in catch is obse-
rved in jigs having 60 g weight compared 
to others. 
Table III shows the details of catch 
in different specifications of wooden jigs. 
The 12.5 em long jigs having weights of 
60 g were superior to the other specifi-
cation of jigs, fcJlowed by the jigs having 
15 em length and 60 g weight. In general 
the catching rate of aU jigs of 50 g weight 
was found to be poor. The jigs of 12.5 em 
length groups landed 42.6% of the total 
catch by number. Thus it may be noted 
that there was noteworthy difference in 
VoL IX No 1 1972 
their logarithmic values. The results are 
given in Table VIII 
The critical difference was formed for 
comparing the average logarithmic catch of 
fish landed by the jigs of different weights. 
It could be seen that jigs of 12.5 em 
length with 60 g weight were catching more 
fish by weights compared to jigs of 50 and 
70 g. In the case of jigs with 15 em length 
no significant difference can be attributed 
to the catch rate of jigs of 60 and 70g 
73 
Pillai et al: Standardisation of specifications for different trolling lures. 
Table VIII 
For jigs with 12.5 em. length and 50, 60 & 70 g. weights. 
Source of variation ss DF MS 
Total 7.2039 38 
Between weights 2.5630 2 1.2815 
Error 4.6409 36 0.]289 
* Significant at l% level 
Critical difference : 0.2816 
For jigs with 15 em. length and 50, 60 & 70 g. weights. 
Source of variation 
Total 
Between weights 
Error 
ss 
5.8889 
1.0237 
4.8652 
DF 
38 
2 
36 
*Indicates significance at 5% level 
Critical difference : 0.2885 
MS 
0.5119 
0.1351 
F 
9.94* 
F 
3.791('. 
weights. Hewever, significantly lower catch 
was reported for jigs of 50 g weight. 
landed by jigs of different weights is given 
in table IX after converting the figures 
Fig clearly :reveals the superiority 
of the fish head jigs having 60 g weight 
in its catching rate. Out of the total 
catch, jigs of 60 g weight alone account 
for 54%. 
Analysis of variance technique was 
used for comparing the catch efficiency of 
of the jigs of different weights. The ana-
lysis of variance of the number of fish 
Table 
Source ss 
Total 5.6336 
Weights 0.8925 
Error 4.7411 
into their corresponding logarithmic 
values. 
It could be seen from the table that 
between weights variations were significant 
at 5% level and jigs with 60 g weight, 
landed significantly higher number of fish. 
The analysis of variance for the wei-
ghts of fish landed by jigs of different 
weights is given in table X. 
IX 
DF MS F 
53 
2 0.4462 4.80"' 
51 0.0930 
Critical difference : 0.2030 
* Significance at 5% lBveL 
Mean logarithmic catch - 50 g 
0.4070 
60 g 
0.7107 
70 g 
0.4867 
FISHERY TECHNOLOGY 
Pillai et al: Standardisation of specifications for different trolling lures. 
Table X 
Source SS DF MS F 
Total 8.3999 53 
Weight 2.2120 2 1.1060 9.12* 
Error ______________ ~6~.1~8~79~ ___________ 5_I ____________ o._I_2_13 _________ __ 
Critical difference : 0.2324 
* Significance at 1% level. 
Here too between weights, variations 
are significant at 1 % level indicating that 
the catch rates of jigs of different weights 
were not similar. The mean logarithmic 
weights of fish landed by jigs weighing 
50 g, 60 g, and 70 g, are 0.5204, 1.0161 
and 0.7646 kg respectively. It is quite evi-
dent from these figures that jigs weighing 
60g weight landed significantly higher catch. 
Table V is a comparative statement 
of the efficiency indices of different spe-
cifications of buffalo horn jigs with those 
of wooden jigs and galvanised iron jigs. 
A study of the table would reveal that jigs 
having 12.5 em length and 60 g weight 
are superior to jigs of other specifications 
in their catching efficiency. 
Fig.3 shows the catch rate of buffalo horn 
jigs of different lengths irrespective of 
weight and jigs of different weights irres-
~50 
i 40 
.; 30 
;: 
~ 
10 
Speclficctiatt of Jto 
F;g.:S. CATCH COMPOSITION OF BUFFALO HORIO JIGS OF DlFI"Eiiii!!NT 
L!NQTM AND WEIGHT. 
pective of length. Of the three length spe-
cifications, 12.5 em and of three weight 
speeifications 60 g weight jigs were found 
superior to those of the other specifications. 
VoL IX No 1 1972 
SUMMARY 
Fishing operations carried out with 
buffalo horn, wooden and galvanised iron 
jigs of different physical specifications 
rigged up in troll lines, revealed that jigs 
of 12.5 em length having 60 g weight are 
superior to those of other specifications 
in luring seer fish. Fish head jigs when 
tried in their three specifications of wei-
ghts, viz, 50, 60 and 70 g, showed that 
jigs of 60 g have a higher efficiency index 
than those of 50 and 70 g weights. 
ACKNOWLEDGEMENT 
The authors express their sincere thanks 
to Dr. V. K. Pillai, Director, Central Ins-
titute of Fisheries Technology, for gran-
ting permission for publicatiDn of this 
paper, to Shri G. K. Kuriyan, Senior Fis-
hery Scientist for his valuable guidance 
in the course of the experiments and for 
suggestions for its presentation and to 
Shri H. Krishna Iyer, Assistant Fishery 
Scientist (Statistics), for statistical analysis 
of the data. 
REFERENCES 
Deshpande, S. D. and Sivan, T. M. 1969. 
Fish Techno!; (1), 26-34. 
Milne, D. J. 1955. Progress report of the 
Pacific Coast Stations No. 103, pp. 3-5. 
Sivan, T. M. and Panikar, P. Appukutta. 
1969. Fish Techno!; (l), 117-119. 
Subramonia Pillai, N., Manohardoss, R.S. 
and Hameed, M. ShahuL 1970. Ibid, 
(1), 20-22. 
75 


Standardisation of specification for different trolling lures

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Standardisation of specification for different trolling lures

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