GUDUSIA CHAPRA

M O R P H O M E T R I C C H A R A C T E R S A N D T H E I R R E L A T I O N S H I P I N

G U D U S I A C H A P R A ( H A M . )

S. L. CHONDAR* Received September, 29, 1973

ABSTRACT

Mathematical relationships of different morphometric characters of Gudusia chapra are dealt with in this paper. The relationships determined by least squares method, by fitting straight line y = a + bx, are found to be linear. The ratio and the percentage of measttroments of the various body parts are computed and described systematically in a comparative form. A new finding regarding the origin and positio~ of lhe dorsal and pelvic fins at different stages of life of the species is recorded.

INTRODUCTION

MORPHOMETRIC characters are very important so far as identification of a species of fish, and they have been commonly employed by several authors for such study. The present paper deals with the studies on the morphometric characters with their various mathematical relationships of Gudusia chapra. In identification of this species, the various morphometrical characters described by Day (1878, 1889), Shaw and Shebbeare (1937), Fowler (1941), Misra (1959) and Srivastava (1968), are found to be varying. Moreover, detailed studies on the various morphometric mathematical relationships of the species have not probably been made before by any previous workers. The equations, relating to the various morphometric relationship of the fish derived here, can be fruitfully utilised in the con- version of one measure into the other. The present communication is thus considered to be essential to see how far the morphometric characters observed by the author differ from those of the previous workers, and at the same time to determine the general equations of various relationships of the different body parts measurements of the species.

* Present address : Regional Trainin8 Centre for Inland Fisheries Operatives, Agra (India).

51 B 1--August 74

52 S . L . CHONDAR

MATERIAL AND METHODS

The specimens used for this investigation were obtained from the commercial catches of the Keetham reservoir. The reservoir is situated about 22 km north of Agra in Uttar Pradesh (India). It has an area of about 254 hectares and is connected with the river Jamuna by the Agra canal near Delhi.

Samples were first taken at random from the catches and then various detailed studies were done only on the specimens selected for the particular aspect of the study. Specimens were collected at regular fifteen days inter- val during the period from March to June, 1969. Fish measuring upto 192 mm in total length could be recorded during the period of investigation, although Day (1878) and Misra (1959) reported the length of the species as being at least 8 inches (or 203 mm). Only fresh specimens were utilised in this work.

Specimens having a total length between 71 and 192 max were treated for various body measurements. Excepting the eye and the snout, all other body measurements were taken on millimetre scale of a modified type of measuring board (Unpublished), and the measurements were rounded to the nearest 0" 5 mm on eye estimation. The eye and the snout length were measured by Vernier Callipers, and the least count was made to 0" 1 ram.

All scale-measurements were sufficiently and accurately taken as lateral distances, keeping them perpendicular to the reference axis. The line of intersection of the plane of the measuring board and the end wall which passes through the reference point had been considered as a reference line, and the tip of the snout as the reference point.

The measurements were taken on the left side of the fish. The following measurements were made on each specimen:

1. Total length, from premaxillary symphysis, when the mouth is closed, to the tip of the lower lobe of caudal fin when stretched out (T.L.).

2. Standard length, from premaxillary symphysis, when the mouth is closed, to the base of the centre rays of caudal fin (S.L.).

3. Head length, from premaxillary symphysis, when the mouth is closed, to the posteriormost point of operculum (H.L.).

4. Snout length, from premaxillary symphysis, when the mouth is closed, to the anteriormost point of the anterior border of eye (S).

Morphometric Characters of Gudusia chapra (Ham.) 53

5. Eye diameter, the maximum longitudinal distance across the eye (E). 6. Predorsal length, from premaxillary symphysis, when the mouth

is closed, to origin of dorsal fin (PD.L.). 7. Prepelvic length, from premaxillary symphysis, when the mouth

is closed, to origin of pelvic fin (PP.L). 8. Preanal length, from premaxillary symphysis, when the mouth

is closed, to origin of anal fin (PA.L.). 9. Body depth, the maximum distance between the dorsal and ventral

lines of the body (D). 10. Caudal length, from the base of the centre rays of caudal fin to

the tip of its lower lobe, when stretched out. 11. Preorbital length, from premaxillary symphysis, when the mouth

is closed to the posteriormost point of eye. 12. Postorbital length, from the posteriormost point of eye to the

posteriormost point of operculum.

OBSERVATIONS AND RESULTS

The comparative data relating to the various body measurements of the fish are presented in Table !. Measurements on total length; standard length; head length; the length of the eye and the snout; predorsal, prepelvic and preanal lengths; and the maximum body depth of 24 selected specimens of various sizes ranging from 71 to 192 mm were computed in the table in order to study the various morphometric relationships.

Origin and Position of Dorsal and Pelvic Fin at Different Length Groups

Observations of Table I would indicate that upto 140 mm in total length of the fish, the origin of the dorsal fin, excepting in one case, was anterior to that of the pelvic fin; and above 140 mm length, the dorsal fin in most cases commenced posterior to the pelvic (Fig. 1). Further, in the specimens below 140 mm total length, the average percentage value of the predorsal length (37"0) was found to be less than that,, of the prepelvic length (38"4), and this showed the position of the dorsal fin being anterior to the pelvic. In the fishes above 140 mm length, the average percentage value of the predorsal length (37"9) being more than that of the prepelvic length (37" 5) indicated the dorsal fin to be posterior to the pelvic. The positions of the dorsal and the pelvic fins appeared to be nearly or just opposite each other on 140 mm length of the fish. The straight line relationship between

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Morphometrie Characters of Gudusia chapra (Ham.) 55

the total length-predorsal length and the total length-prepelvic length plotted on the basis of calculated values indicated the crossing of the lines at 140 mm of the total length of the fish (see Fig. 2), and this could be produced in support of the view. However, a detailed investigation is needed for the confirmation of these observations. But according to Day (1878) the origin of the dorsal fin is opposite or slightly before that of the pelvic; and Whitehead (1965) stated 'pelvic origin below unbranched dorsal rays or just in front.'

Ratio and Percentage Values of Body Parts and Their Relationship

The various body parts measurements in the ratio and percentage of total, standard and head lengths of the fish have been computed in Tables II and IlI. The ratio and percentage values of various morphometric measurements of this species as indicated by the previous investigators have also been denoted in the footnote of the tables so as to compare those with the present data. The tables would themselves give a clear picture of a comparative account of various relationships between the morphometric characters dealt with here.

Predorsal and prepelvic lengths.--Although the findings in the fore- going results indicated the varying positions of the dorsal and pelvic fins at different length groups, the ratio and percentage values of the predorsal and prepelvic lengths for the entire length group of the fish under study (see Tables II and III) showed that the dorsal fin is just anterior to the pelvic.

Head length and caudal length.--Irrespective of sizes of the fish, the length of the head was greater, in about 92 ~o, than that of the caudal fin. Out of these 92 ~ cases, the head in most cases was only a little more than that of the caudal fin. The average length of the head (28" 97 mm) was more than that of the caudal (26-31 mm). The average ratio of head (4"22 in T.L. and 3'31 in S.L.) and the caudal fin (4"71 in T.L. and 3"72 in S.L.) also revealed that the head was slightly greater than the caudal fin ('caudal fin just less than head length'--Whitehead, 1965). The average percentage values of the head (23"6 in T.L. and 30"2 in S.L.) and the caudal fin (21"5 in T.L. and 27"6 in S.L.) also indicated that the length of the former was slightly greater than that of the latter. So it could be safely concluded that in G. ehapra head is 'Usually' just bigger than the caudal fin.

56 S . L . CHONDAR

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Head length and body depth.--Maximum depth of the body was found to be always more than the length of the head, and the differences in the size dimensions of these two measurements were relatively more in bigger sizes of the fish. Fishes of 120 mm or above had this difference, excepting in one case, 5" 0 mm or more and those beiow 120 mm had less than 5" 0 ram. The average ratio values--3"68 in T.L. and 2" 86 in S.L. for body depth, and4 '22 in T.L. and 3"31 in S.L. for head length--proved that the maximum depth of the body was greater than the length of the head. The average percentage values on the measurements of maximum body depth and the head length being 27'1 and 23"6 in T.L. and 34"6 and 30"2 in S.L. respectively, showed that the body depth was greater than the head length.

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FIG. 2. The relation between total length and two body pa~t measurements, viz., M, Predorsal length; N, Prepelvic length of Gudusia chapra. Straight lines drawn on calculated values. Arrow indicated the crossing of the two regressions at 140 mm of total length.

Snout length and eye diameter.--The snout was smaller than the eye in all the individual specimens studied. The eye was fairly large in comparison to the snout and is at the anterior half of the head. In percentage values, the eye showed to be relatively larger being 27"3 as against the snout which was 20"0 per cent in head length,

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Morphometric Characters of Gudusia ehapra (Ham.) 59

Pre-and postorbital lengths.--The postorbital length was in almost all cases more than the preorbital length. The ratio of the postorbital length with the head length was calculated to be between 1 "78 and 2"02, the average being 1" 90. The fact that the average ratio of the preorbital length (2" 10) was a little more than that of the postorbital length (1"90) proved that the preorbital length was just less than the postorbital length. The preorbital length which thus came as 47" 5 percent was found to be slightly less than the postorbital length being 52" 5 percent in the head length. These findings also support the statement of Whitehead (1965)--"preorbital length, including eye, just less than the postorbitat length."

REGRESSION ANALYSIS OF BODY MEASUREMENTS AND THEIR RELATIONSHIP

Regressions of the various body measurements (Table IV) have been calculated from the data of Table I. In various body measurements relationship study, the dependable variables as standard length, head length, predorsal length, prepelvic length, preanal length, and the maximum body depth are found highly correlated with the independable variable, the total length of the fish. The comparative study of the eye or the snout (the dependable variables) with the head length (the independable variable) also showed a high degree of correlationship. The relationships for all the measurements were determined by least squares method by fitting the straight line equation, y = a + bx.

Total Length and Standard Length

In Gudusia chapra the standard length in most cases relatively increases with the increase of the total length. The total length-standard length relationship in this species can be expressed by the equation:

SL = 1"818 q- 0"7717 TL,

where 'SL' is the standard length and 'TL' is the total length of fish in ram. The constant values were to be 1"818 and 0"7717, and the relationship was found to be linear (see 'A ' of Fig. 3).

The coefficient of correlation, ' r ' , was 0"9374, showing a high degree of positive correlation between the two lengths.

Total Length and Head Length

A straight line relationship between the total length and the head length was established (Fig. 4). The constant values were determined as

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Morphometric Characters of Oudusia chapra (Ham.) 61

0"2078 and 0"2183. The total length and the head length indicated a positive correlation ( r = 0"3137), the relationship being,

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where 'HL' and 'TL' denote head length and total length of fish in mm respectively.

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The markings (see Fig. 4) plotted for the head length as percentage of total length against the total length are rather scattered, but the graph suggests that the head length was relatively bigger in fishes below 90 ram.

62 S . L . CHONDAR

Total Length and Predorsal Length

Total length and predorsal length were highly correlated. Total length was increased with the increase of the predorsal length. A linear relationship between the total length and the predorsal length was yielded (see 'M' of Fig. 2), and an equation was calculated which gave the following values :

PDL ---- --2"1633 + 0'3918 TL,

where 'PDL' and 'TL' represent the predorsal length and the total length in mm respectively. The constant values were - -2"1633 and 0"3918.

The coefficient of correlation (r ~-- 0'9998) showed a very high degree of positive correlation.

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Total Length and Prepelvic Length

The relationship between the total length and the prepelvic length may be expressed by the equation:

PPL = 1" 608 + 0" 3667 TL,

where 'PPL' = prepelvic length and ' T L ' = total length of fish in mm, and 1'608 and 0'3667 wore the constant values. The relationship was


found to be linear and has been graphically depicted in Fig. 2 (See 'N ' of Fig. 2). The total length and the prepelvic length showed also a very high degree of positive coefficient of correlation (r = 0"9953).

Total Length and Preanal Length The relationship between the total length and the preanal length was

linear (see 'B ' of Fig. 3). The straight line equation was found out to be,

PAL = -- 0"6003 + 0'5515 TL,

where 'PAL' is the preanal length and 'TL ' is the total length in ram. -- 0"6003 ano + 0"5515 were the constant values. The above relationship indicated that the preanal length did increase as the square of the total length of fish.

The coefficient of correlation, ' r ' , was calculated as 0'9951, indicating a very high degree of correlation between the two lengths.

Total Length and Maximum Body Depth The depth of body is highly correlated with the total length and the

former was relatively increased with the increase of the latter. A linear relationship was obtained between the total length and the maximum body depth when the data for body depth was plotted against the total length of the fish (see ' C ' of Fig. 3). The relationship was found to be,

D = -- 2"435 + 0' 2926 TL,

where ' D ' = maximum depth of body and ' T L ' = total length of fish in ram, and - -2"435 and 0"2926 were constant values.

The body depth and the fish length showed a high degree of positive correlation (r = 0"9912).

Head Length and Snout The head and snout lengths, which have been plotted as a scatter dia-

gram (see 'a ' of Fig. 5), showed a straight line relationship between the two measurements. The relationship between the head length, HL, and the snout length, S, may be expressed as:

S = 0"2244 + 0" 1930 HL,

where 0"2244 and 0" 1930 were the constant values. The correlation coefficient, ' r ', was calculated to be 0'9863, showing

a high degree of correlation between the two lengths.

64 S . L . CHONDAR

Head Length and Eye

There is a direct proportional increase in diameter of eye with the increase in head length. The relation between the diameter of eye and the head length was determined and a regression line fitted to the data (see ' b ' of Fig. 5). The eye and the head length showed a high degree of positive correlation (r = 0'9778), the relationship being,

E = 1 "036 + 0"2354 HL,

where E = Eye, HL = Head length, and 1"036 and 0"2354 were constant values.

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FI~. 5. The relationships of Snout (a) and Eye (b) showed against the head length of Uudusia chapra.

Morplwmetric Characters of Gudusia chapra (Ham.) 65

DISCUSSION

The comparative account represented in this article regarding the study on morphometric relationships of Gudusia chapra gives a clear idea about the variations recorded by different previous authors and the present author. The variations found in the percentage values of the various body measurements as described by Whitehead (I965) and those by the author are not major, excepting in the range of the caudal length measurement. The long range of the caudal length (15"8 to 38"8 in percentage of standard length) could be recorded here owing to the availability of three such specimens which do not have normal sized caudal fins. "Ibis may be due to abnormal growth of the caudal fin in proportion to the rate of growth of other body parts. But the average percentage value of the caudal fin, calculated as 27"6, shows its measurement to be not much different from the measurement range, 30" 0-30" 3 in percentage of standard length, as recorded by Whitehead (1965). Similarly, excepting in the case of caudal length, the ratio values of the morphometric relationships between the various body parts does not show any marked difference in the descriptions of the authors under reference. q~he variability in the mor phometric characters of the fish and their relationships found in the descriptions of the different authors is due to the variations in the size range as well as in the number of the specimens recorded by them. Moreover, for the morphometric study of the fish, different workers had collected their specimens from different waters of various places, which might have different ecological conditions. It is not unlikely that the ecological conditions have an influence on the proportionate growth of the various body parts, and the variations in the morphometric relationship of the specimens collected from different waters may probably be owing to the differences in the environment.

Whitehead's description about the measurement o f ' h e a d more than 28 per cent of standard length in G. chapra' does not fully tally with the findings of the present author in two individual specimens where the head length appeared to be 26'4 and 27"8 per cent respectively (i.e., less than 28 per cent), but his observation could be true if the average percentage value of the head estimated here as 30" 2 is taken into account.

SUMMARY

Twenty-four selected specimens of Gudusia chapra 71-192 mm were studied for various morphometrical relationships.

long

66 S, L. CttONDAR

The origin of the dorsal fin was found to be opposite to that of the pelvic on 140 mm in total length of the fish. Whereas in the fish below 140 mm length the dorsal was generally anterior to the pelvic fin and above 140 mm posterior to it.

The ratio and the percentage of measurements of the various body parts were computed and described systematically in the comparative account of the morphometrical relationships.

Morphometric characters like total length, standard length and head length; predorsal, prepelvic and preanal lengths; snout length; diameter of eye and maximum depth of the fish were compared by the method of regression analysis. Various relationships involving different body measurements were determined by least squares method by fitting straight line, y ----- a + bx . The relationships are governed by the formulae:

1. Total

2. Total 3. Total 4. Total 5. Total

6. Total 7. Head 8. Head

length--Standard length: SL = 1"818 ÷ 0"7717 TL

length--Head length: HL = 0"2078 ÷ 0"2183 TL length--Predorsal length: PDL = -- 2" 1633 ÷ 0"3918 TL length--Prepelvic length: PPL =- 1" 608 + 0" 3667 TL

length--Preanal length: PAL = -- 0"6003 + 0"5515 TL length--Body depth: D = -- 2"435 ÷ 0"2926 TL length--Snout: S = 0'2244 + 0" 1930 HL length--Eye: E =- 1" 036 q- 0' 2354 HL.

ACKNOWLEDGEMENT

The author is indebted to Shri N. K. Velankar, Director, Central Insti- tute of Fisheries Education, for kind constant encouragement; to Dr. C. P. Singh, Head of the Department of Zoology, Agra College, for kind advice and to Shri B. K. Lehri, Lecturer of Statistics, Institute of Social Science, Agra University, for help in the statistical treatment of the data. To Shri P. K. Sen, Senior Instructor, Regional Training Centre for Inland Fisheries Operatives, my thanks are due for assistance in compiling the data.

Day, F.

REFERENCES

The Fishes o f India, William Dawson and Sons Ltd., London, 1878, 1, 639--40 (Printed photo-litho offset, 1958).

The Fauna of British India fncluding Ceylon and Burma, London, 1889, 1, 375.

S. L. Chondar Proc. Ind. Acad. Sci., 13, Vol. LXXX, PI. III

Fie. 1. A Gudusia chapra of 175-0 mm in total length, showing the pelvic fin being anterior to dorsal. The origin of dorsal fin at 66.5 mm and pelvic below 65" 0 mm.

Morphometric Characters of Gudusia chapra (Ham.) Fowler, H. W.

67

.. "Co.qtributions to the biology of the Philippine Archipelago and adjacent regions," Bnll. U.S. Nat. Mus., 194~, 13 (100), 634.

Hamilton, F. .. Fishes of Ganges, Edinburg, 1822, 1, 248, 383, 182.

Misra, K . S . .. "An aid to the identification of the common commercial fishes of India and Pakistan," Rec. Indian Mus., 1959, 57 (1-4), 119.

PiUay, T. V .R . .. "A morphometric study of Hilsa, Hilsa ilisha (Ham.) of the river Hooghly and the Chilka lake," Indian d. Fish., 1957, 4, 344-86.

Schaefer MiMer, B. .. "Morphometric comparison of yellow-fin tuna from south- east Polynesia, Central America and Hawaii," Inter. Amer. Trop. Tuna Com. Bull., 1955, 1 (4), 61.

Shaw, G. E. and Shebbeare, E. O. "The fishes of Northern Bengal," J. Asiat. Soc. Bengal Sci., 1937, 3, 12.

Srivastava, G. .. Fishes of Eastern Uttar Pradesh, Vishwavidyalaya Praka- shan, Varanasi, 1968, 4-5.

Whitehead, P. J .P . .. "A preliminary revision of the Indo-Pacific Alosinae (Pisces: Clupeidae)," Bull. Brit. Mus. Nat. Hist., 1965, 12(4), 115-56.

S z--August 74

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