The characteristics of the fish and prawn seed resources of the Gulf of Kutch are described. Results of experiments conducted in a primary low saline reservoir of a solar salt works to study their utility for aquaculture are reported. The prospective role of aquaculture in augmenting fish production along the coast is also discussed

Devmurari, H.L.

Gopalakrishnan, P.

Joshi, K.D.

Krishna Raju, V.

Madhusudhan Pillai, K.

Somaiya, V.J.

Aquatic Commons

Observations on e Fish and Seed Resources e 
Gu of and eir Uzation in uacu 
P. GOPALAKRlSHNAN, V. KRISHNA RAJU, K. MADHUSUDHAN PILLAI, 
K. D. JOSHI, V. J. SOMAIY A and H. L. DEVMURARl 
Tata Chemicals Limited, Mithapur - 361 345 
The characteristics of the fish and prawn seed resources of the Gulf of 
Kutch are described. Results of experiments conducted in a primary low saline 
reservoir of a solar salt works to study their utility for aquaculture are reported. 
The prospective role of aquaculture in augmenting :fish production along the 
coast is also discussed. 
Gopalakrishnan et al. (1975) and Trivedi 
et al. (1982) have studied the characteristics 
of the fish and prawn seed potential of the 
Gulf of Cambay region. Dave et al. (1982) 
conducted preliminary seed surveys along the 
south east coast of the Gulf of Kutch.In the 
present paper, a comprehensive account of 
the potential and seasonal abundance of the 
seed along the south west coast of the Gulf 
of Kutch and the cultivability of different 
species in a large seawater reservoir of a salt 
works is given. The scope of aquaculture 
along the coast is also discussed. 
Materials and Methods 
Fish seed was collected from creeks and 
mangrove channels using drag nets of 5 m 
length and 10 mm mesh and cast nets of 
2.5 m.dia and 10 mm mesh during both low 
and high tides between 0600-1800 h during 
1977 and 1978. Altogether 600 samples 
were studied. 
Prawn seed was collected by funnel shaped 
monofilament l mm mesh shooting net in 
the seawater channels and creeks for 60 -
90 min during high and low tides between 
0600-1800 h, duringl979and1980. Altogether 
400 samples were analysed. The influence 
of tide and lunar periodicity was worked 
out by pooling together collections sep1rately 
for respective high tide, low tide, full moon 
and newmoon periods. 
Experiments on the salinity tolerance and 
growth rate were conducted by stocking the 
Vol. 24, 1987 
seed of prawns in small ponds as well as the 
reservoirs and sampling periodically. 
Fishing in the reservoirs was done by 
210/1/3, 210/2/3, 210/3/3 nylon gillnets of 
units having 350 m length, 3 m hung depth 
and mesh sizes oi 65 to 90 mm. The data 
on the species composition is based on 600 
fishes collected throughout 1980-84. 
Prawns were harvested from the reservoir 
using nylon cast nets of 2.5 m dia. having 
10 mm mesh size, for 8 days around each 
full moon· and newmoon from 12th phase 
of the ascent to 4th phase of the descent. 
Data on the species composition and lunar 
periodicity was recorded from 192 samples 
during 1980-84. 
Hydrological data of salinity and tem-
perature were recorded regularly and data 
on rainfall obtained from the records of the 
factory. 
Topography and locality 
The area of study was a 29 km landstrip 
along the mouth of the Gulf of Kutch near 
Port Okha (Lat 22° 28' N Long 69° 05' E). 
The land is arid with no rivers flowing into 
the Gulf. The tidal range is 4.94 m, expo-
sing vast intertidal areas during ebb tides. 
Rich faunal and floral growth occur in the 
intertidal and subtidal areas (Gopala-
krishnan, 1970). 
Sparse population of dwarf mangroves 
of species A vicinnia provide litter, forming 
6 P. GOPALAKRISHNAN, V. KRISHNA RAJU, K. MADHUSUDHAN PILLAI, 
K. D. JOSHI, V. J. SOMAIY A AND H. L. DEVMURARI 
detritus along the bottom. The sea has also 
abundant phyto and zoo plankton produ-
ction (Bhaskaran & Gopalakrishnan, 1971). 
Layout of the reservoir 
The reservoir is constructed by bundhing 
up the intertidal rann area of a mangrove 
mudflat. The water depth is 25-60 cm with 
20-40 cm thick silt along the bottom. Tidal 
water was pumped into the reservoir by 
vertical pumps from a seawater channel for 
onward fl.ow to connected series of reser-
voirs. AH reservoirs were non-drainable. 
Fresh seawater was pumped into the first 
reservoir for 8-12 h daily, round the year 
except for the monsoon months of August-
September. The inlet of the reservoir was 
screened with 20 mm mesh monofi.lament 
webbing to restrict entry of large predators. 
Results and Discussion 
Hydrology 
The seawater temperature ranged from 
l 8.5°C in January to 35.3 °C in June. The sali-
~ity varie.d from 30 %0 in August to 39.8 %0 
m June m the seawater channel; however, 
the range was 15 to 44 %
0 
in the reservoir. 
The annual rainfall was 400 mm. 
However in 1979 and 1980 unprecedented 
rainfall of 800 mm and 1000 mm. were recor-
ded due to cyclonic conditions. Dissolved 
oxygen in the reservoir ranged from 4.1 to 
6.8 p p.m. and the pH ranged from 7.6 
to 8.2. 
Fish seed 
An annual seed potential of 2.2 million 
fries and fingerlings of mullets (74.5 %), milk 
fish ( 4.1 %), seabreams (18.4 %) and grunters 
(3.0 %) was estimated. The catch/net/h 
(number) ranged from 1636 in August to 
11,415 in January (Table 1). Mullets were 
represented by Mugil cephalus, Mugil parsia, 
Mugil macrolepis, Mugil cunnesius, Mugil 
tade, Mugil seheli, Mugil carinatus and Mugil 
waigiensis. The seabreams consisted of 
non-predatory Gerres setifer and Gerres 
filamentosus and the predatory grunters were 
Pomadasys spp and Chrysophrys spp. The 
collections made during the early phase of 
ebb tides were richer. The average size 
observed was 15-90 mm for mullets, 70-160 
mm for milk fish and 50-75 mm for sea-
breams and grunters. 
Salinity, growth and production trend 
The fishes were abundant upto 40 %0 
salinity and beyond that, predatory perches 
were more common. An average growth 
of 300 mm (330g) in respect of Chanos chanos, 
240 mm (300 g) in respect of M. ceplalus 
and 160 mm (125 g) in respect of lesser 
mullets was observed. The non-predatory 
seabream, Gerres spp recorded 120 mm 
(60-70 g) growth in one year. Largest Mugil 
cephalus (2.5 kg), M. tade (2.0 kg), M. parsia 
(350 g), M. macrolepis (200 g), Lates calcari-
fer (7.0 kg), Chanos chanos (13 kg), Chryso-
phrys sp (1.0 kg), Pomadasys spp (1.4 kg) 
and Gerres spp (350 g) were also recorded 
during the study. 
The production from daily fishing, showed 
an annual average catch of 8470 kg from 
436 hectare area with a catch/hectare/yr of 
19.4 kg and 4.8 kg/h. Monthly :fluctuations 
of the landings are given in Table 2. The 
production showed two peaks, in January 
and June. The catch comprised of 21 species 
of fish contributing 94% and the crabs 6 %-
It was observed that the mullets of all 
species carried ripening ovaries in maturity 
stages III and IV during January-February 
and July-August period. Experiments to 
mature them fully and spawn in controlled 
hboratory conditions with mullet pitutary 
hormones showed encouraging results in 
Mugil parsia in 34 days. However fertilisa-
tion could not take place as male spawner 
was not available during the final stages of 
experiment. 
Prawn seed 
An annual potential of 47.6 million prawn 
seed, of which 69.6 % penaeids, was estimated. 
Penaeus merguensis (54 %), Metapenaeus 
kutchensis (27.5 %), Metapenaeus brevicornis 
(18.5 %), and occasionally Metapenaeus 
monoceros were represented. The catch/net/h 
(number) of total seed observed was 159.5 in 
January to 20876.5 in August. Their monthly 
fluctuations are given in Table l. 
Dave et al. (1982) noted a penaeid prawn 
seed abundance in the south east coast of Gulf 
FISHERY TECHNOLOGY 
~ 
Cll 
B l:I:: 
:-""' > 
N e '~ 
...... 
'i::I \Cl 
00 Table 1. Monthly fluctuations of major fish and prawn seed dw·ing 1977-1980, catch/net/h (nos) ~ 
-..] > 
Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec. ~ 
Fish seed 7231 
Cll 
nos 11415 6890 4735 5762 4798 1499 2103 1636 4865 5600 7297 ~ Mugil cephalus % 12.0 15.0 39.0 20.0 27.5 25.1 - - - - 1.0 1.5 
Other mullets % 51.0 63.4 61.0 80.0 72.5 60.2 77.8 60.0 80.0 21.2 53.1 72.3 ~ 
Perches ~,:i 37.0 21.6 - - - 14.7 10.0 15.0 10.3 76.3 45.9 26.2 tn Cll 
ChanoJ chanos % - - - - - - 12.2 25.0 9.7 2.5 - - 0 ~ 
Prawn seed. nos 159.5 372.0 760.0 476.5 849.0 525.0 4005.0 20876.5 5460.5 4325.0 1003.5 303.0 (") 
Penaeus 
tn 
Cll 
merguensis % 43.7 41.0 17.0 26.0 31.0 42.0 48.5 29.0 22.0 24.0 56.0 66.0 0 
Metapenaeus 
"1j 
kutchensis % 49.0 37.0 59.0 28.0 47.0 37.0 27.5 37.0 45.0 39.0 24.0 20.0 CJ c: Metapenaeus I:""' 
brevicornis % 3.0 8.0 19.0 21.0 4.0 5.0 8.0 25.0 14.0 16.0 9.0 11.0 "1j 
Palaemon spp. % 4.3 14.0 5.0 25.0 18.0 16.0 16.0 9.0 19.0 21.0 11.0 3.0 0 "1j 
~ 
c: § 
-...) 
8 P. GOPALAKRISHNAN, V. KRISHNA RAJU, K. MADHUSUDHAN PILLAI, 
K. D. JOSHI, V. J. SOMAIYA AND H. L. DEVMURARI 
of Kutch from May to July during high tide 
periods. Whereas, the present investigations 
showed that this peak extended upto Novem-
ber and that 56.3 % of the penaeid seed were 
collected during low tides indicating a ten-
dency of the juveniles to stay longer in the 
mangrove areas. The lunar periodicity in 
relation to juvenile abundance was 52.13 % 
for new moon to 47.87 % for full moon. A 
size range of 05-120 mm for P. merguensis, 
06-105 mm in respect of M. kutchensis and 
06-75 mm for M. brevicornis was noted. 
The average model size of the seed was 
however 37 mm, 35 mm and 28 mm respecti-
vely. 
Salinity tolerance, growth and production 
trend 
The overall tolerance to varying salinities 
of the reservoir for different seasons, was 
34 % for M. kutchensis, 0.5 % for P. merguen-
sis and 0.02 % for M. brevicornis. P. mer-
guensis showed 38 % survival upto 36 %
0 
salinity and beyond it only 2 % survived upto 
40 %0 salinity. In case of M-. kutchensis the 
survival was 36-40 % and M. brevicornis 
showed survival trend similar to P. merguen-
sis upto 38 % and thereafter succumbed to 
increasing salinities quickly. A growth rate 
of 22-24 mm/month upto 33 %0 salinity 
14-15 mm upto 36 %0 salinity, and 5-6 mm/ 
month upto 38 %0 salinity was observed in 
case of P. merguensis. M. kutchensis showed 
14-15 mm/month, 6-8 mm/month and 3-4 
mm/month and M. brevicornis showed 7 mm/ 
month and 3 mm/month (upto 38 %0 salinity) 
for respective salinity gradients. 
Batch harvests during 1980-84 yielded 
an average annual catch of 5670 kg prawns 
from the reservoir area of 336 hectare with 
a catch/hectare of 16.9 kg and catch/h 
effort value of 3.4 kg. The fluctuations of 
landings showed two distinct peacks, in 
February-May and August-November 
(Table 2). 
The catch was more during the newmoon 
fortnights (55.25%). It was seen that during 
February - May, 79.5% catch was 
during new moon fortnights, whereas during 
Au.gu.st - Novemb~r, the fullmoon fort-
nights, accounted for 64.5% prawns. The 
species composit:i.on was M. kutchensis 
(96.2%) followed by P. merguensis (2.7%) 
and rest comprised of M. brevicornis and 
M. monoceros. The size range observed 
was 90-150 mm in respect of P. merguensis, 
80-120 mm in respect of M. kutchensis and 
70-90 mm in resp:::ct of M. brevicornis and 
M. monoceros. Another interesting obser-
vation was the availability of maturing 
females of P. merguensis, M. kutchensis 
and M. brevicornis in stage 3 and 4 during 
the peak harvests. Successful spiwning of 
P. merguensis, M. kutchensis and M. 
brevicornis was carried out in laboratory. 
Prospects for aquaculture develop1nent 
The estimate of 35.2 million quality fish 
and prawn seed for the small strip of coastal 
area, suggests massive seed potential along 
the Gulf of Kutch and Saurashtra coast as 
similar ecological and topographic features 
exist. Extensive surveys to assess the massive 
realistic seed resource potential for the whole 
area is however essential. It is estimated 
that 42200 hectares of coastal area in Gujarat 
state is covered under salt works and most 
of them are in the Saurashtra - Kutch belt. 
About 4000 hectares of primary reservoir 
areas can be suitably harnessed .for fish and 
prawn production. Autostocking would 
reduce the seeding expenditure though the 
productivity of prime foh and prawns would 
be reduced due to predation and competition. 
Since most of the predators. and competitors 
are also good edible varieties., daily fishing 
for their removal would ensure steady supply 
of material to consumers. Despite the 
shallowness of reservoir and heavy silting 
which tends to create anaerobic conditions 
during summer in the too shallow areas, 
and the avain predation by migratory birds 
like herons, pelicans etc. conspecous in 
the salt works, the fish and prawn stock was 
free from diseases like 'soft shell' and parasi-
tic infections and the production was fairly 
economic (Table 3) to suggest application 
of similar activity in other areas. 
Natural maturation of prawns and pros-
pects of induced maturation of mullets pro-
mise opportunities. to utilise them for arti-
ficial seed production programme to subs-
tantially supp:'.ement the natural resources 
of prime varieties. Bes.ides the programme 
FISHERY TECHNOLOGY 
< 'Tl 0 F-1 
:--' Cf) 
N ::i:: 
~..{::>. Table 2. Monthly fish and prawn production and composition of species > 
,_. z 
\0 Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. v 00 
-..] Fd 
Fish kg 1437.5 906.9 421.0 627.0 489.1 1076.4 312.0 152.0 342.4 570.0 986.4 1200.0 ~ 
lYJugil cephalus % 2.6 8.5 5.1 3.4 22.6 17.2 25.6 5.3 10.l 40.0 11.8 11.2 ~ Mugi! tade % 4.7 1.2 7.6 - 0.5 - - 2.0 6.1 1.8 2.6 1.1 
Mugil parsia % 2.8 3.9 0.9 0.7 16.4 3.3 17.1 - 2.0 0.7 1.2 Cf) tTJ Mugi! tTJ 
macrolepis % 20.8 45.9 20.3 7.2 2.6 8.6 3.4 8.9 7.6 l.6 2.1 22.9 v 
Chan.as chanos % 4.3 0.7 0.8 4.6 9.2 1.2 - 1.0 3.6 2.7 3.9 2.6 id 
Lates calcarifer % 0.5 I. 7 4.1 3.3 0.7 1.4 0.5 2.3 1.1 1.9 7.7 5.2 tr! en 
Chrysophrys 0 
cuvieri % 1.0 - 0.7 0.8 2.0 3.3 - - - 6.5 0.9 1.6 e 
Chrysophrys ~ 
be rd a % 2.4 2.7 1.4 - 2.7 6.4 1.0 2.6 13.9 16.2 25.3 15.6 tTJ 
Argyrops Cf) 
spinifer % - - - - - - - - 2.7 0.3 2.9 2.0 0 'Tl 
Pomadasys 0 maculatus % 2.3 2.7 7.2 11.3 8.8 24.1 0.7 0.8 2.3 5.4 11.3 1.4 e Gerres setifer % 47 .. 6 15.6 27.7 5.0 14.5 5.0 21.4 1.0 18.4 1.3 0.7 22.0 r 
Gerres 'Tl 
filamentosus % - - - - - - - - - - 1.2 - 0 
Si!lago sihama % 1.8 'Tl - - - - - - - - - -
Elops sawrus % 7.8 9.2 16.4 34.8 10.2 12.1 9.3 9.0 18.8 12.8 12.7 7.0 P'1 e P!atycephalus r..:; 
insidator % 2.2 2.0 - - - 0.8 - - - - 0.8 1.2 (J 
Pseudo rhombus ::i:: 
arsius % - 1.8 1.0 7.7 3.5 2.0 - - - - 11.6 1.0 
Muraenosax 
cine re us % - - - - - - - - - 1.0 1.0 
Eleutheronema 
tetradactylum % - 1.3 2.0 - - - - - 10.5 
Scatephagus 
arsius % - - 1.2 0.7 - - - - 3.8 
\0 
>-' 
0 
Table 2. (Contd.) 
Jan. Feb. Mar. Apr. May June July Aug. Sept. Oct. Nov. Dec. 
Nematalosa ;d 
nasus % 0.6 - - 0.9 2.3 - 55.9 - 2.5 - -- 0 Epinephelus 0 
merra % - - - 2.9 1.3 - - 1.5 "'d 
Miscellaneous % 0.4 2.8 1.9 1.5 0.4 0.9 1.7 1.4 0.5 1.0 0.8 2.0 > r 
Crab kg 2.7 1.2 7.2 119.2 23.5 91.2 55.2 12.0 5.5 17.7 29.9 22.9 > ~ 
Scylla serrata % 1.7 19.0 5.0 8.5 18.0 8.0 1.6 3.0 3.0 0.5 ~ 
Prawns kg 107.0 257.5 764.9 877.3 601.3 38.9 21.3 202.7 861.8 1340.0 670.9 212.2 Cl'.l ::0 Penaeus z 
merguensis % 3.0 2.0 1.6 3.0 8.5 2.3 - 1.0 4.0 2.3 1.2 4.0 ~> 
Metapenaeus t:J;.Z 
kutchensis % 96.0 97. l 98.0 96.3 90.5 95.1 100.0 98.7 96.0 96.3 96.3 94.0 '<! 
Metapenaeus '-9 • o~ brevicornis % 1.0 0.4 0.4 0.5 0.7 2.6 - - - 1.4 2.5 1.0 (/) :;:d 
Metapenaeus ::0 1-j ~Cl'.l 
monoceros ~ 0.5 - 0.2 0.3 - 0.3 - - - 1.0 <::o , 0 
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FISH AND PRAWN SEED RESOURCES OF GULF OF KUTCH 
Table 3. Fish and prawn production pattern 
of salt works reservoir 
Item 1980 1981 1982 1983 1984 
Fish(kg) 5600 7450 11500 7400 10400 
Market 
value (Rs.) 18800 27600 31800 46400 81430 
Prawn 
(kg) 4209 4644 7591 4343 7566 
Market 
value (Rs.) 52186 58821 65427 44756 78806 
of aquaculture also would generate rural 
employment in this traditionally drought 
prone area. The most significant contri-
bution from the programme would be pro-
duction of massive quantities of good fish 
of price within the reach of the economically 
weaker sections of the society. 
At present there is a wide gap between the 
production and demand of seafood in the 
Saurashtra-Kutch region. The coastal fishing 
limited for a period from August to May, 
produced 1144 t at an average of 2.5 
kg/h catch rate in 1981 compared to 1590 t 
at 4.4 kg/h of 1980. Except during 
May and October months, the catch was 
bvlow 100 t/month (George et al., 1982). 
In this declining trend, the prawn, Metapena-
eus kutchensis, the main contributor in the 
present aquaculture study, contributed 7.8 
to 10.0%. Iyer et al. (1981) estimated the 
idle capacity of freezing plants in this zone 
at an alarming 84.6%, due to shortfall in 
raw material supply, among other reasons, 
accounting for 89.6% .It is thereafore obvious 
that concerted efforts by Government and 
Vol. 24, 1987 
private agencies to develop aquaculture 
utilising the vast expanse of tidal waste lands 
available, adopting suitable technology would 
be greatly helpful to combat this deficit of 
raw material for export industry and indi-
genous consumption by masses. 
The authors express their deep gratitude to Mr. 
D.S. Seth, Chairman of Tata Chemicals Limited and 
the Management of the company for their keen 
interest and generous encouragement during the 
course of the study. 
References 
Bhaskaran, M. & Gopalakrishnan, P. (1971) 
Indian J. Fish. 18, 99 
Dave, H. B., Bhaskaran, M., Chhaya, N.D. 
& Mu.lia, K. D. (1982) Proc. Symp. 
Coastal Aquaculture l, 183 
George, N. J., Suseelan, C., Thomas, M. M., 
Kakati, V. S. & Nalini, 0. (1982) Mar. 
Fish. Infor. Serv. T & Ser. 43, 8 
Gopalakrishnan, P. (1970) J. Mar. Biol. 
Ass. India, U, 15 
Gopalakrishnan, P., Koshy, P.K.&Mukund, 
M. Jani (1975) J. Mar. Biol. Ass. 
India, 17, 653 
Iyer, Krishna H., Srinivasa RaD, P., Unnithan, 
G. R., Kesavan Nair, A. K. & Nair, 
R. G. (1981) Fish. Technol. 18, 109 
Trivedi, Y. A., Chhaya, N. D. & Koshy, 
P. K. (1982) Proc. Symp. Coastal Aqua-
culture 1, 187 


Observations on the fish and prawn seed resources of the Gulf of Kutch and their utilization in aquaculture

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Observations on the fish and prawn seed resources of the Gulf of Kutch and their utilization in aquaculture

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