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CHAPTER NO. 5

HEPATOSOMATIC INDEX AND

GONADOSOMATIC INDEX

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INTRODUCTION

B.carnaticus plays important role in the diet as a source of proteins,

vitamins and minerals such as calcium, iron etc. which is essential for

healthy growth and development of man. In rural areas poor people can‟t

afford to buy vegetables and meat in their daily meal,so it is the fish

B.carnaticus which is easily available to them and fulfill their nutritional

requirement.

As the introduction on different aspects of biology of this species

is very scanty and considering its importance an attempt is made to study

the different aspects of gonadosomatic index (GSI) (ovary and testis ) and

hepatosomatic index ( HSI ) of this species.

Fish body weight and weight of gonad gives the gonadosomatic

index ( G.S.I. )It is the ratio of fish gonad weight to body weight , it is

particularly helpful in identifying days and seasons of spawning , as the

ovaries of gravid females swiftly increase in size just prior to spawning.

The development and growth of gonad simultaneously takes place in the

fish and fish grows and the G.S.I. is high. Present study insured that the

growth of fish, body weight and gonadal development is correlated.

Gonadosomatic index of fish is related to spawning and reproduction of

fish.B.carnaticus is a good source of food for poor people and hence they

must be reproduced in large number so that they are easily available to

poor people and hence the study of G.S.I. is important and essential. At

maturity stage fish has maximum G.S.I. value and after spawning G.S.I.

value declines. The G.S.I. value also related to amount of food available

to them in water and temperature of water also. So generally during the

breeding season of this B.carnaticus shows maximum G.S.I. value and

after spawaning it is reduced. In this study we have carried out G.S.I. of

male and female fish simultaneously. When G.S.I.. of both sexes were

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compared we came to know that maximum values of G.S.I. have occurred

almost at the same time in both sexes and after spawning it is recoreded

that there was a great decrease in G.S.I. values.

On the other hand study of Hepatosomatic index of B.carnaticus is

also carried out simultaneously. H.S.I. is associated with the liver

energetic reserves and metabolic activity. When the food is available in

large amount and conditions are favourable it causes increase in the H.S.I.

value. Increase in the daily weight of the body is related to the increase in

the H.S.I. value and it is also observed that H.S.I. also depends upon

seasonal cycle. As liver is vital organ in the body and it performs various

physiological functions such as it converts excess sugar into glycogen,it

detoxify the toxic substances, it also act as a haemopoietic organ,destroy

the old R.B.C.etc. So its healthy condition is essential for growth of fish.

As weight of body increases weight of liver also increases. The H.S.I.

gives us information about the condition of liver and body and also about

the impact of water pollution on it. H.S.I. also provides an indication on

status of energy reserve in fish. In poor environment fish usually have a

smaller liver with less energy reserved in the liver. H.S.I.has been

reported to decrease in fish exposed to water pollution. H.S.I. values are

indirect indices of energy status on a seasonal basis the H.S.I. values are

variable.

All the statistical analysis was performed by the use of Microsoft

Excell 2007. During study it is observed that there is a correlation in the

increase in the body weight and weight of the gonads i.e. the ovary and

testis in female and male fishes respectively. It results in the increase of

G.S.I. value . The knowledge about G.S.I. is essential for evaluating the

potentials of its stock life histories, practical culture and actual

management of the fishery.

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H.S.I. value also provides us information about the healthy

condition of fish and also about the quality of water, because higher

H.S.I. value means fishes are growing rapidly and have a good aquatic

environment and if H.S.I. value is less it means fish is not growing well

and it is facing unhealthy environmental problems. Thus both G.S.I. and

H.S.I. values gives us indications of development pattern of fishes

B.carnaticus which is a food of poor people and that‟s why they must be

reproduced in large number and must be made available to them

throughout the year. To know the breeding potentials of this fish it is

essential to know about their G.S.I. values.

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MATERIAL AND METHODS

Fish samples of B. carnaticuswere collected from Girna Dam ,

constructed on the Girna river at Nandgaon Dist. Nasik. Maharashtra

state. For the determination of HSI. And GSITen individual fish were

sampled randomly in each month for the experimental year 2011. Fish

samples B. carnaticus were brought to the laboratory and they were

blotted by blotting paper and there body weights were recorded to the

nearest milligram respectively. The HSI.and GSI. Values were calculated

from the ratio of total body weight and gonadal weight.After weighing,

fish were dissected to remove the liver and gonads from them for the

determination of HSI. and GSI. Moisture of the liver and gonads was

removed with the help of blotting paper and then weight of liver and

gonads was recorded in grams. The hepatosomatic index of the fish was

determined by the use of equation cited by Parmeswaran (1974).

H.S.I. =

Similarly the gonadosomatic index of the male fish( i.e. the weight

of testis) and female fish (i.e. the weight of ovaries) were determined by

equation cited by Parmeswaran (1974).

G.S.I. =

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In such a way weight of liver, and gonads (i.e. male and female ) of every

fish per month is recorded and the mean value of the liver and gonads

(testis and ovaries ) of ten fishes per month is given in the table

(no.28).The mean value of liver and gonads of every month of year 2011

gives an idea about the condition of the liver of the fish and maturity of

the fish. The health of fish is directly related to the condition of liver

because it is the organ related with the digestion of food and storage of

reserved food. So the good condition of the liver is the indication of the

good health of fish. Similarly the good and healthy condition of the

gonads is the indication of maturity of fish for the breeding season.

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RESULTS

In present investigation in B.carnaticus of equal weight variation was

found with liver, ovary and testis through out the year. B.carnaticus

follows the normal gonadal development and liver development and

possesses normal reproductive behavior. The mean G.S.I. value for testis

is (18.4317) observed higher in the month of June and low in month of

January 3.2995.The G.S.I. (Ovary) value observed higher in the month of

(June)and lower in month of January Similarly the higher mean H.S.I.

value observed in the month of June And lower mean H.S.I. value is

observed in the month of January (Table No.28). In the graph peak values

were observed in the month of June for mean G.S.I. (Testis)(Graph no.

89) and G.S.I. (Ovary) (Graph no.88) and for mean H.S.I. Peak values in

graph gives us an idea about energy level and metabolic activity of the

fish in that month. (Graph no,90).Similarly we get an information about

gonadal developmental stage and its maturity and reproduction cycle

throughout the year. It is observed that G.S.I. and H.S.I. variation is

common in fish and they are correlated with each other and some workers

have suggested that the reproductive capacity of fish varies according to

availability of space and food.

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Table No 28 Mean H.S.I., G.S.I. and S.T.D.V. of B.carnaticus

for the year 2011.

Month Mean

STDV

H.S.I

Mean

GSI

STDV

GSI

Mean

GSI

STDV

GSI

H.S.I Testis Testis ovary

Jan 0.5144 0.0495 3.2995 0.16436 3.6044 0.3059

Feb 0.7387 0.067 3.9493 0.0951 4.5361 0.0479

March 0.8281 0.0171 4.4275 0.4972 4.016 0.06886

April 0.9134 0.0261 4.9253 0.6341 4.3566 0.3217

May 0.9271 0.0604 9.6677 2.9328 9.5369 0.4384

June 1.4098 0.1209 18.4317 0.8431 18.5728 1.0046

July 1.2543 0.0556 17.4366 0.8272 15.8968 2.3929

Aug 1.2661 0.0425 14.4972 0.8375 13.2979 1.01584

Sep 1.2743 0.0184 12.8008 0.4746 13.1784 0.7537

Oct 0.9048 0.0425 8.4531 0.6451 8.3228 0.8012

nov 0.766 0.0424 7.8993 0.7819 6.1981 0.6195

Dec 0.6872 0.2313 4.1688 0.2182 4.8661 0.2453

* each value is a mean of ten fishesh per month.

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Graph no 88

Natural Changes in GSI values of female B.carnaticus During 2011

0

2

4

6

8

10

12

14

16

18

20

Ch

an

ge

in

GS

I

Months

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Graph No. 89

Natural Changes in GSI values of maleB.carnaticus During 2011

0

2

4

6

8

10

12

14

16

18

20

Ch

an

ge

in

GS

I

Months

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Graph No. 90

Natural Changes in HSI of B.carnaticus During 2011

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

Me

an

HS

I

Months

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DISCUSSION

In the present investigation maximum mean G.S.I. (Testis) value

(18.4317) was found in the month of June which indicates the period of

maximum growth in male fish. Similarly maximum mean G.S.I. (Ovary)

value (18.5728)was found in the month of Junewhich indicate the period

of maximum growth in female fish B.carnaticus. A sharp drop in mean

G.S.I. values of male and female fish takes place in the month of January

(3.2995) and (3.6044) respectively this indicates the spawning occurred

before this month. However the breeding season of B.carnaticus starts in

month of early June and it is extended until September.During monsoon

the development and growth of gonad of B.carnaticus simultaneously

took place and hence mean G.S.I. values of both male and female are

higher in breeding season. G.S.I. values increase with increasing mean

body weights and length during gametogenesis in females.

Another factor might be responsible for increase in G.S.I. values in

both male and female of B.carnaticus in the month of May and June is

significant rise in the temperature of water 26.5+-0.50c. Chmilevskiy and

Lavroa (1990) reported that during low temperature (200c) division of the

primary sex cells and gonia was inhibited completely stoping their to

early prophase meiosis.Chmilevsky (1995a) further showed that

differentiation of the female gonads was suppressed in low temperature.

Maximum G.S.I. values corresponds with the spawning season of fish.

Barnabe (1994) reported that high G.S.I. of seabass were found at peak of

its spawning season.

Reviews of oocyte development in teleost fish have been given by

de Vlaming (1983), Guraya (1986, 1994), Selman et al; (1993), Bromage

and Cumaranatumga (1988), Selman and Wallace (1989); West (1990)

and Tyler and Sumpter (1996). The development follows a similar pattern

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in most species. In cyprinid, Meyyen (1927, 1939, cited in Testis weight

and G.S.I clearly changed according to reproductive season reaching their

peak values in the prebreeding season coinciding with the large

accumulation of spermatozoa. Values decreased with spawning in the

breeding season and then rose again in the post breeding season.

Significant differences in testis weight and G.S.I value were found only

in the breeding season. Gonadosomatic index indicates gonadal

development and maturity of fish. It increases with the maturation of fish

declining abruptly thereafter (Parmeswaran et al, 1974).

Testis weight and G.S.I. clearly changed according to reproductive

season in all groups reaching their peak values in the preceding season

coinciding with the large accumulation of spermatozoa G.S.I. (Testis)

values decreased with spawning in the breeding season and then

increased again in the past breeding season. In males the decrease in

G.S.I. corresponds to the loss of gonad weight which is due to the

elimination of the spermatid residual bodies.

The condition of the liver and whole body, as measured with the

heptosomatic index (H.S.I.) can provide information on potential

pollution impacts. Although these parameters are not very sensitive, they

may serve as an initial screening bio meter to indicate exposure and

effects body condition is a practical tool for biologist and managers to

guess the overall health of fish population and a good indicator of fish

habitat quality and pollution levels. While some authors claimed that

H.S.I. might be useful as an indicator of chemical pollution of water,

others showed that it was inconsistent as a biomarker and that it is

dependent on the seasonal cycle. Prior to establishment of H.S.I. as a

pollution indicator standard ranges should be established, and the possible

effects of intestinal biological rhythms and environmental factors on this

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parameters must be accessed.The maximum value for H.S.I. was recorded

in October, while the minimum was in March. Varied between 1.14 and

6.67.In the females the decrease in G.S.I. is the result of ovulation and

characterizes the peak of spawning activity.Temporal changes in G.S.I.

has been used to provide rough estimation of spawning periods for fishes.

In B.carnaticus G.S.I. value peaked in earlyJune and decreased

through late September suggesting spawning period occurred from June

to September, which is similar to the results of Gaikwad M.V.et.al;

(2009), where the ratio between the body weight and the weight of the

gonad showing the status of the ovary in terms of maturity and denotes

the phase of reproduction cycle.The G.S.I. of air breathing fish Channa

gaucha (Ham)found increased with the maturation of the fish and gonad.

Where the G.S.I. was found lowest during post spawning phase and was

highest at the peak of maturity during spawning phase. There is intimate

relationship between the length of ovary and its relative weight.High

G.S.I. high fecundity , low G.S.I. low fecundity . The G.S.I. signifies the

varied number of oocytes observed during study. The peak of the

breeding phase was observed in June where the G.S.I. is higher and rest

of the months deserved for low egg production and low G.S.I. This

information can be helpful for better management of inland fisheries and

prevention of fish capture in breeding season to conserve the fish

diversity.The same result was reported by Lutfun Hussain et al; 2003 in

case of Dhela (Osteobrama cotiocotio). The maximum G.S.I. value was

found in the month of June which indicated the maximum gonadal

growth . A sharp drop in the G.S.I. value had taken place in September

which might have been caused by spawning .The peak value in G.S.I.

coincided with peak spawning period thus showing a close relationship

between the two. In the present study, high values of G.S.I. denoted

attainment of peak maturity of gonads. Hence the high G.S.I. values

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indicate that the peak spawning takes place during June to December.

Shaikh and Prakash Lohar, (2011) also reported that low G.S.I. of Labeo

rohita, Cyprinus mrigala, carp fish during October to January may be due

to dormancy of gonads in post breeding season. The G.S.I. values

correlated with increased amount of protein and lipids in both

prebreeding and postbreeding seasons may be due to augmented

vitellogenesis in ovary and spermatogenesis in testes that require large

amount of lipoproteins.Weight of the gonad followed regular cyclic

changes that were correlated with the reproductive activities of fish. The

lowest G.S.I. values indicated that during this period the weight of the

ovary in fish was minimum possibly due to dormancy of gonads in post

breeding season. Most of the fishes show seasonal variations in

reproductive physiology. Since the gain in weight was recorded in the

gonads of each fish species. During the months of June to September

every year it can be clearly correlated with the breeding season of fish.

On the basis of observed values of G.S.I. in adult fish a reproductive life

cycle of B.carnaticuscan be concluded.It is observed that February –May

is prebreeding season, June – September is breeding season and October

– January is post breeding season of B.carnaticusin each year. The G.S.I.

values also correlated with increased amount of protein and lipids it may

be due to augmented vitellogenesis in ovary and spermatogenesis in testes

that requires large amount of lipoproteins under impact of hormones.

Kingdom T. and Allison M.E., (2011) studied the fecundity and

gonadosomatic index ,hepatosomatic indices in Pellonula leonensis. In

case of B.carnaticus breeding commenced soon after the begining of

monsoon and continued until August with a peak in late June and early

July.Monsoon rain and flood triggers the spawning activity in this species

as amply evidenced during field studies.

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H.S.I. is associated with liver energetic reserves and metabolic

activity. H.S.I. had a maximum value in the month of June. Availability

of sufficient amount of food material in the above said month is

responsible for increase in H.S.I. from (0.5144) (January) to (1.4098)

(June). Yang and Bauman,(2006) stated that H.S.I. depends on seasonal

cycles. Difference in the H.S.I. values that were found in this study

ranging between 0.5144 and 1.4098 were probably also caused by diet in

natural conditions that differed throughout the year.

Mean G.S.I. and H.S.I. values increased with increasing mean body

weights and length‟s during gametogenesis in females.The peak value of

G.S.I. coincides with the peak values of the spawning period indicating

close relationship between G.S.I. and H.S.I. Gross indices are sometimes

indicative of toxicant effects. The condition of the liver and the whole

body as measured with H.S.I. can provide information on potential

pollution impacts. It is used to indicate exposure and effects.

Some authors claimed that H.S.I. might be useful as an indicator of

chemical water pollution, others showed that it was inconsistent as a bio

marker and it is dependent on the seasonal cycle prior to establishment of

H.S.I. As a pollution indicator standard ranges should be established and

the possible effects of internal biological rhythms and environmental

factors on this parameters must be assessed.

Slight increase in the H.S.I. values in the present data was reffered

to the accumulation of pollutants as suggested by many authors.(Kendall,

1977 and Mazhar et. al.,1986) Saleh ( 1982) reported that, liver is the

good indicator of the aquatic environmental pollution where one of the

important function of the liver is to clean any poisons or pollutants from

the blood coming from the intestine.The pollution of the aquatic

environment causes an increase in the heptosomatic index. This probably

227

means that the H.S.I. could be used as a quick indicator for detecting

pollution in the aquatic environments. As a matter of fact , the amount of

pollutants in the fish liver is directly proportional to the degree of

pollution in the aquatic environment by heavy metals and pesticides.

Accordingly the heptosomatic index may be considered as a valid

indicator for this type of pollution.

H.S.I. is most important because it describes stored energy in fish.

Low values of H.S.I. were found from to And in, the mean value was

significantly lower (p<0.05) in relation to other months. In January H.S.I.

increased suddenly and from February on the tendency of the values was

to rise with an exception for the month of April when a significant drop

was recorded. H.S.I. low values were found during receding and dry

period. This result is similar to the one found by Saint-Paul (1984) for

neotropical characoid fish Colossoma macropomum specimens collected

from Lago Manaquiri. The low values found may be due to the usage at

stores accumulated in the liver for supplying energetic requirements

during the time of scarce food items, sexual products elaboration and

spawning activity , which occur throughout the flooding and early rise

respectively . During receding and rising water periods most specimens

present little accumulation of fat in the abdominal cavity.

It is also observed that there is correlation in H.S.I. and G.S.I. i.e.

mean H.S.I. and G.S.I. values increase with increase in mean body

weights and length during gametogenesis in females. Changes in G.S.I.

and H.S.I. followed a similar pattern during gametogenesis. This finding

is similar to that reported for other species e.g. Awaji and Hanyu, 1987,

Delahunty and de vlaming, 1980, Htun-Hun, 1978. Asahina et al, 1990.

Since total fish length and weight are included in the calculation of G.S.I.

and H.S.I., they present an auto correlation.