Present study describes the length-weight (LWR) and length-length (LLR) relationships of a freshwater catfish Eutropiichthyes vacha Hamilton from Indus River, Sindh, Pakistan. A total of 281 specimen of E. vacha were collected from fisherman?s catch from February 2005 to January 2006, are used for this study. The parameters a and b of the length-weight relationship were calculated as W= aLb are presented. 

The values for allometric coefficient b of the LWR were close to isometric value for male (b = 3.159) and combined values for both sexes (b = 3.053). However, it suggested negative allometric growth for females (b = 2.973). Results for LLRs indicated that these are highly correlated (r2 > 0.9) 

P< 0.0001

Baloch, W.A.

Jafri, S.I.H.

Soomro, A.N.

Suzuki, H.

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Online version is available on http://research.guilan.ac.ir/cjes or www.cjes.net CJES  Caspian Journal of Environmental Sciences Caspian J. Env. Sci. 2007, Vol. 5 No. 2 pp. 143~145  ©Copyright by The University of Guilan, Printed in I.R. Iran   [Research]   Studies on length-weight and length-length relationships of a catfish Eutropiichthyes vacha Hamilton (Schilbeidae: Silurifo- rmes) from Indus river, Sindh, Pakistan  A.N. Soomro1, 2*, W.A. Baloch1, S.I.H. Jafri1 and H. Suzuki2  1- Department of Fresh Water Biology and Fisheries, University of Sindh, Jamshoro-76080, Sindh, Pakistan 2- Laboratory of Aquatic Resource Science, Fisheries Faculty, Shimoarata 4-50-20 Kagoshima University, Kagoshima 890-0056 Japan * Corresponding author’s E-mail: anilaalisoomro@yahoo.com   ABSTRACT Present study describes the length-weight (LWR) and length-length (LLR) relationships of a freshwater catfish Eutropiichthyes vacha Hamilton from Indus River, Sindh, Pakistan. A total of 281 specimen of E. vacha were collected from fisherman’s catch from February 2005 to January 2006, are used for this study. The parameters a and b of the length-weight relationship were calculated as W= aLb are presented.  The values for allometric coefficient b of the LWR were close to isometric value for male (b = 3.159) and combined values for both sexes (b = 3.053). However, it suggested negative allometric growth for females (b = 2.973). Results for LLRs indicated that these are highly correlated (r2 > 0.9) P< 0.0001.  Keywords: catfish, Eutropiichthyes vacha, Indus river, length-weight, length-length, relationships.   INTODUCTION Catfish are most abundant group of fish.  Eutropiichthyes vacha Hamilton, locally called as Challi, is one of the most important freshwater catfish of Pakistan. It belongs to order Siluriformes and family Schilbeidae. Among the small sized fishes it has high economic importance and market value. Locally it is sold from Rs.120-150/ Kg because of its export to Middle East countries like UAE (personnel survey). In Pakistan it is found in all type of freshwaters in warm areas (Mirza & Bhatti 1999). From Pakistan no work has yet been reported on any aspect of E. vacha.  The mathematical relationship between length and weight of fishes is a practical index suitable for understanding their survival, growth, maturity, reproduction and general well being (Le Cren 1951). Length-weight relationships are useful in fishery management for both applied and basic use (Pitcher & Hart 1982) to (i) estimate weight from length observations; (ii) calc- ulate production and biomass of fish population; and/or (iii) provide information on stock or organism condition at the corporal level. Length-length relationships (LLRs) are also important in fisheries management for comparative growth studies (Moutopoulos & Stergiou 2002). Present work will provide baseline information for the growth of catfish from Indus River and it can be supportive in future for the management of catfishes in Pakistan.  MATERIALS AND METHODS In total 270 fish specimen used for present study, were collected from River Indus, near G.M Barrage (Kotri Barrage) Jamshoro, Sindh, Pakistan. Regular monthly samples were obtained from fishermen’s catch at fish landing center near Kotri Barrage during February 2005 to January 2006. Specimens were brought to the laboratory of the Department of Fresh Water Biology and Fisheries, University of Sindh, Jamshoro. Total length (TL) fork length (FL) and Studies on length-weight and length-length relationships of a catfish 144 Standard length (SL) were measured using measuring board (cm), while body weight was determined as total weight including gut and gonads, using a digital balance to the nearest 1g. Fish were dissected to determine their sexes on the basis of gonads. Minimum length of mature male was 15 cm, while for females it was >14 cm, hence smaller than 14 cm (females) and 15 cm (males) were considered immature and were not included in present study. The values of constants aand b were estimated from the log transformed values of length and weight i.e. log W = log a + b log L, via least square linear regression (Zar, 1984). The coefficient a is the intercept, and the regression of coefficient b is an exponent, indicating isometric growth when equal to 3.0, a value larger or smaller than 3.0 shows allometric growth (Bagenal & Tesch 1978). Furthermore, relationships in between (i) TL v/s SL (ii) SL v/s FL (iii) FL v/s TL were also estimated by using the above least square linear regression equation.  RESULTS AND AND DISCUSSIONS From the total of 270 specimens of E. vacha used for the length-weight and length-length relationship studies 142 were males, while 128 were females, contributing (52.6%) and (47.4%) respectively. The results of length weight relationship (Table 1) indicated close to isometric growth for males (BW = 0.0039 TL 3.159, r2 = 0.955) and negative allometric growth for females (BW = 0.0072 TL 2.958, r2 = 0.976). The results for combine values of both sexes also indicated the positive allometric growth (BW = 0.0054 TL 3.053, r2 = 0.964). The results of length-weight relationship are indicating difference between the male, females and combined values (Fig. 1). The value of b for females is below 3.0 that show the rate of increase in body length is not in proportional to the rate of increase in body weight. This change may be because of various factors which effect the growth of fish, those may be including season, habitat, gonadal maturity, sex, stomach fullness, health and preservation techniques (Tesch 1971; Begenal & Tesch1978). The b values for male and combined LWR were > 3.0 (Table 1), it indicates that the male E. vacha grow as the cube of the length. All allometric coefficients (b) estimated in this study were within the expected range 2.5-3.5. According to Pauly and Gayanilo (1997), b values may range from 2.5 to 3.5 suggesting that result of this study is valid. All the LLRs values are given in table 2. The values for coefficient of determination (r2) for all the length-length parameters of male, female and combine were > 0.9, and were highly significant (P< 0.0001). The present study provides baseline information on LWRs and LLRs for E. vacha Hamilton, that will be useful for researchers and fishery managers in future.                                           Fig 1. Relationship between standard length (mm) and body weight (g) for male (a), female (b) and combined of E. vacha (c). Malesn =142y = 3.1593x - 5.554R2 = 0.955201234560 0.5 1 1.5 2 2.5 3 3.5 4ln Lln WFemalesn =128y = 2.9577x - 4.9347R2 = 0.97601234560 0.5 1 1.5 2 2.5 3 3.5 4ln Lln WBoth sexesn =270y = 3.0528x - 5.228R2 = 0.964301234560 0.5 1 1.5 2 2.5 3 3.5 4ln Lln Wa b c Soomro et al., 145  Table 1. Regression coefficient for length-weight relationships for some Siluriformes fishes. Species Sex n a b r2 Authors Mystus baramensis B 41 0.004 2.875 0.917 Martin-Smith (1996) Mystus vittatus M 1407 0.023 2.959 0.953 Hossain et al., (2006) Mystus vittatus F 1031 0.018 3.134 0.965 Hossain et al., (2006) Mystus vittatus B 2438 0.020 3.058 0.958 Hossain et al., (2006) Eutropiichthyes vacha M 142 0.0039 3.159 0.955 present study* Eutropiichthyes vacha F 128 0.0072 2.958 0.976 present study* Eitropiichthyes vacha B 270 0.0054 3.053 0.964 present study* B= both sexes; M= male; F= female; n= number of individuals; a= intercept; b= slope; r2= coefficient of determination; *= p<0.0001.  Table 2. Length-length relationships between total length (TL), fork length (FL) and standard length (SL) of Eutropiichthyes vacha. Sex Equation n a b r2 Male TL= a+bSL 142 1.2048 0.9062 0.9651*  FL= a+bTL  0.9379 1.0145 0.9711*  SL= a+bFL  0.9181 1.0489 0.9921* Female TL= a+bSL 128 1.1581 0.9377 0.9770*  FL= a+bTL  0.9412 1.0113 0.9817*  SL= a+bFL  0.9499 1.0230 0.9810* Combined TL= a+bSL 270 1.0167 0.9226 0.9712*  FL= a+bTL  0.9403 1.0124 0.9767*  SL= a+bFL  0.9342 1.0357 0.9864* n= number of individuals; r2= coefficient of determination; a= intercept; b= slope; *= p<0.0001.  REFERENCES Agarwal, N.K. (1996) Fish reproduction. APH Publishing Corporation, N. Delhi. pp. 157. Begenal, T. and Tesch, F.W. (1978) Age and Growth. Method for assessment of fish production in freshwater. (ed. Bagenal T.), IBP Hand book, Blackwell Scientific Press, Oxford. Hossain, M.Y., Ahmed, Z. F., Leunda, P. M., Jasmine, S., Oscoz, J. Miranda, R. and Ohtomi, J. (2006) Condition, length-weight and length-length relationship of the Asian striped catfish Mystus vittatus (Bloch, 1794) (Siluriformes: Bagridae) in the Mathb- hanga River, southwestern Bangladesh. J. Appl. Ichthyol. 22, 304-307. Le Cren, E.D. (1951) The length-weight relationships and seasonal cycle in gonad weight and condition in the perch (Perca fluviatilis). J. Anim. Ecol. 20, 201-219. Martin-Smith, K.M. (1996) Legth-weight relationships of fishes in diverse tropical fresh-water community, Sabah, Malaysia. J. Fish. Biol. 49, 297-298. Mirza, M.R. and Bhatti, M.N. (1999) Biodiversity of the freshwater fishes of Pakistan and Azad Kashmir. Proc. Aq. Biodiversity, Pakistan (eds. Q.B. Kazmi and N.A. Kazmi). pp. 177-184.  Moutopoulos, D.K. and Stergiou, K.I. (2002) Length-weight and length-length relation- ships of fish species from Aegean Sea (Greece). J. Appl. Ichthyol. 18, 200-2003. Pauly D, Gayanilo Jr. F.C. (1997) A Bee: An alternative approach to estimating the parameters of a length-weight relationship from length frequency samples and their bulk weights. NAGA ICLARM, Manila, Phili- ppines. Pitcher, T.J. and Hart, P.J. (1982) Fisheries Ecology. Chapman and Hall, London.   Tesch, F., W. (1971) Age and Growth. Methods for assessment of fish production in fresh waters. (ed. Ricker W. E.). pp. 99-130. Blackwell Scientific Publications, Oxford. Zar, J.H. (1984) Biostatistical analysis. Prentice Hall, New Jersey. pp. 718. 

Studies on length-weight and length-length relationships of a catfish Eutropiichthyes vacha Hamilton (Schilbeidae: Silurifo)

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Studies on length-weight and length-length relationships of a catfish Eutropiichthyes vacha Hamilton (Schilbeidae: Silurifo)

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