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. 2012 Dec;23(2):59–65.

Length-weight and Length-length Relationship of Longsnouted Catfish, Plicofollis argyropleuron (Valenciennes, 1840) in the Northern Part of Peninsular Malaysia

Nor Aziella Mohd Rosli 1,*, Mansor Mat Isa 1,2
PMCID: PMC3799404  PMID: 24575234

Abstract

Scanty information exists pertaining to the length-weight relationship (LWR) and length-length relationship (LLR) parameters of longsnouted catfish, Plicofollis argyropleuron in lotic systems throughout the northern part of Peninsular Malaysia. It is vital to reveal these biological properties of P. argyropleuron in Kuala Muda and Merbok estuary for future management and to increase knowledge about this fish stocks. The fish samples were randomly collected in the estuary area of Kuala Muda and Merbok, Kedah for 10 months from March 2009 to December 2009. The values of the exponent b in the LWR equations (W = aLb) were approximately 3, indicating an isometric growth with high correlation coefficient (r2). The value of LLR (r2>0.9) indicated that they are highly significant and highly correlated. These parameters are essential for evaluating the relative condition of fish and species managements as well as their fisheries and stock assessment.

Keywords: Plicofollis argyropleuron, Length-weight Relationship, Length-length Relationship

INTRODUCTION

Plicofollis argyropleuron or longsnouted catfish is locally known as ikan duri in Malaysia. It belongs to the order Siluriformes and family Ariidae. The Ariidae family is comprised of 14 genera and 120 species of tropical and sub-tropical marine catfishes. P. argyropleuron feed on detritus, prawns, soft-bodied organisms and mud (Kailola 1999). Generally, these species attain large sizes, are long living, slow growing, have low fecundity and mouth-breed their egg (Velasco & Oddone 2004). The Malaysian waters recorded 17 species of Ariidae and 10 of that those were estuarine and coastal inhabitors (Mansor et al. 1998).

The length-weight relationship (LWR) and length-length relationship (LLR) have been applied for basic uses in order to make fish stocks and population assessment (Ricker 1968). In fish, size is generally more biologically relevant than age, mainly because several ecological and physiological factors are more size-dependent than age-dependent. Consequently, length-weight regressions have been used frequently to estimate weight from length because direct weight measurements can be time-consuming in the field (Sinovcic et al. 2004).

Present research attempted to provide baseline information for the growth of P. argyropleuron on the basis of the LWR and LLR studies. The estimated LWR and LLR of P. argyropleuron in this study could provide valuable information for future research in order to make comparison between years and locations.

MATERIALS AND METHODS

Monthly random samples of 5–7 kg of P. argyropleuron were collected from the fish landing sites in Northern Part of Peninsular Malaysia, specifically in Kuala Muda and Merbok, Kedah (Fig. 1). The samples were randomly collected for 10 months from March 2009 to December 2009. Fishes were caught using trammel net and barrier net.

Figure 1:

Figure 1:

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Map showing fishing area and sampling station at Kuala Muda and Merbok, Kedah.

After fish were collected, these samples were temporarily placed in cooling boxes filled with ice and transported to the research laboratory. The collected specimens were systematically identified using the available references (Kailola 1999; Hoese et al. 2006). The total length (TL) of each fish was taken from tip of snout to longest ray of the caudal fin. Then, standard length (SL) was measured from the snout to the end of the vertebral column. Caudal fork length (CFL) was measured from the tip of the snout to the end of the middle caudal fin rays. The TL, SL and CFL were measured in centimeters using a measuring board. Lastly, the body weight (BW) in grams was measured to the nearest 0.1 g using electronic weighing balance.

The LWR was determined by using the data on the measurement of length and weight of P. argyropleuron. The LWR is expressed by using the equation: W = aLb (Le Cren 1951; King 1995; Froese 2006), where W = weight of the samples in g, L = length of the sample in cm, a = constant (intercept), b = constant (slope of regression line). The LWR equation was then transformed into a linear form: ln W = ln (a) + b ln (L) (Arshad et al. 2008). Furthermore, relationships were estimated for: i) CFL/TL; ii) SL/TL; iii) CFL/SL; iv) TL/BW; v) CFL/BW; vi) SL/BW.

RESULTS AND DISCUSSION

A total of 539 specimens of P. argyropleuron were used in this study. The fish specimens ranged from 7.7–32.0 cm in total length and 4.0–455.3 g in body weight. The LWR was calculated by transforming the real data to the linear equation [ln W = ln (a) + b ln (L)]. The value of ln a = −4.873, −4.455, −4.109 and b = 3.089, 3.048, 3.015 were better fitted at r2 = 0.976, 0.9783, 0.9329 respectively. Then these value were transformed into parabolic form and equations obtained were W = 0.007L3.089, W = 0.012L3.048 and W = 0.016L3.015 respectively [Fig. 2(a), 2(b) and 2(c)]. The graph of linear equation of P. argyropleuron are shown in Figures 2(d), 2(e) and 2(f). The value of b<3 shows negative allometric growth, b = 0 shows isometric growth and b>3 shows positive allomeric growth (Morey et al. 2003). All the b values were almost 3, indicating that P. argyropleuron has an isometric form of growth in weight. In simple words, these fish increase in their length with increasing weight in cubic form. According to Pervin and Mortuza (2008), b values may range from 2.5 to 4.0 suggesting that the result of this study was valid. Furthermore, the r2 value of LWR of P. argyropleuron was relatively high. High correlation r2 proved a strong relationship between the length and weight in this species (Ahemad & Irman 2005).

Figure 2:

Figure 2:

Figure 2:

Figure 2:

Figure 2:

Figure 2:

Figure 2:

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Graph of LWR of P. argyropleuron showing (a) W = 0.007L3.089, (b) W = 0.012L3.048, (c) W = 0.016L3.089 and graph with regression equation for P. argyropleuron showing (d) ln BW = 3.089, ln TL – 4.873, (e) ln BW = 3.048, ln CFL – 4.455, (f) ln BW = 3.015, ln SL – 4.109.

The value of b greater than three indicates that the fish become plump as they increase in length and b value lower than three shows that the fish gets slimmer with increasing length (Jobling 2002). There were many factors affecting the value of b throughout the fish life. Several important factors such as gonad development and the availability of food in their natural habitats can greatly affect the b value. Froese (2006) stressed that the value of b can be used to compare the condition of fish at temporal and spatial level. The lotic and lentic environment, polluted and non-polluted environment would also determine the condition of the fish. Fish tend to be heavier in the lotic and lighter in the lentic environment (Mansor et al. 2010).

In this study LLR involved the relationships of TL, SL and CFL. The general equation is y = a + bX. The conversion factor of a and b was used to estimate the length needed. Regression equations for LLR are as follows:

SL      =      1.106 TL+1.667 [Fig.  3(a)]
CFL      =       1.059 TL+0.815 [Fig.  3(b)]
CFL      =      0.903 SL+0.363 [Fig.  3(c)]

Results for LLR indicated that the value of correlation coefficient (r2) are highly correlated, r2 > 0.9 at p < 0.05. Therefore, LLR is important in fisheries management for comparative growth studies (Moutopoulos & Stergiou 2002). The present study would provide baseline information for the growth of P. argyropleuron on the basis of length-length and length-weight. Results for all LLR indicated that the value of correlation coefficient (r2) are highly correlated, r2 > 0.9. The value for correlation coefficient (r2) were 0.929, 0.981 and 0.940 (Fig. 3). All these value were greater than 0.9, hence it is highly significant (p < 0.05).

Figure 3:

Figure 3:

Figure 3:

Figure 3:

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Graphs with regression equation and coefficient of determination (r2) for P. argyropleuron showing length-length relation: (a) SL = 1.106 TL + 1.667, (b) CFL = 1.059 TL + 0.815, (c) CFL = 0.903 SL + 0.363.

CONCLUSION

P. argyropleuron inhabiting Northern Part of Malaysia was between 7.7–32.0 cm in total length. All the LWR equation of P. argyropleuron showed an isometric form of growth and all the LLR of P. argyropleuron showed that all types of length measurement was significant and highly correlated between each other, r2 > 0.9 at p < 0.05. These information would be useful for the baseline of LWR and LLR of these fish stocks.

Acknowledgments

Authors would like to thank the fishermen who cooperated with us. Authors also acknowledge School of Biological Sciences, Universiti Sains Malaysia, Pulau Pinang, Malaysia for providing transport to the sampling location and the facilities to conduct this study.

REFERENCES

  1. Ahemad S, Irman I. 4th Technical Consultation Meeting on Information Collection for Sustainable Pelagic Fisheries in the South China Sea. Kuala Terengganu: Southeast Asian Fisheries Development Centre (SEAFDEC) and Marine Fishery Resources Development and Management Department (MFRDMD); 2005. Information collection for sustainable fisheries in the South China Sea. Country progress report III for Sabah, East Malaysia. Jakarta, Indonesia, November. [Google Scholar]
  2. Arshad A, Jimmy A, Nurul Amin SM, Japar BS, Harah ZM. Length-weight relationships of five fish collected from seagrass beds of the Sungai Pulai estuary, Peninsular Malaysia. Journal of Applied Ichthyology. 2008;24(3):328–329. [Google Scholar]
  3. Froese R. Cube law, condition factor and weight-length relationship: History, meta-analysis and recommendations. Journal of Applied Ichthyology. 2006;22(4):241–253. [Google Scholar]
  4. Hoese DF, Bray DJ, Paxton JR, Allen GR. Fishes. In: Beasley OL, Wells A, editors. Zoological Catalogue of Australia. Vol. 35. Australia: ABRS & CSIRO Publishing; 2006. [Google Scholar]
  5. Jobling M. Environmental factors and rates of development and growth. In: Hart PJB, Reynolds JD, editors. Handbook of fish biology and fisheries. Vol. 1. Oxford, UK: Blackwell Publishing; 2002. pp. 107–109. [Google Scholar]
  6. Kailola PJ. Ariidae (Tachysuridae): Sea catfishes (fork-tailed catfishes) In: Carpenter KE, Niem VH, editors. FAO species identification guide for fishery purposes The living marine resources of the Western Central Pacific, vol. 3 Batoid fishes, chimaeras and bony fishes part 1 (Elopidae to Linophrynidae) Rome: Food and Agriculture Organization; 1999. pp. 1827–1879. [Google Scholar]
  7. King M. Fisheries biology, assessment and management. Oxford, UK: Fishing News Books; 1995. pp. 79–192. [Google Scholar]
  8. Le Cren ED. The length weight relationship and seasonal cycle in gonad weight and condition in Perch (Perca fluvialitis) Journal of Animal Ecology. 1951;20:201–219. [Google Scholar]
  9. Mansor MI, Kohno H, Ida H, Nakamura HT, Aznan Z, Abdullah S. Field guide to important commercial marine fishes of the South China Sea (SEAFDEC MFRDMD/SP/2) Kuala Terengganu, Malaysia: Marine Fishery Resources Development and Management Department, Southeast Asian Fisheries Development Center; 1998. [Google Scholar]
  10. Mansor MI, Che Salmah MR, Rosalina R, Shahrul Anuar MS, Amir Shah Ruddin MS. Length-weight relationships of freshwater fish species in Kerian River Basin and Pedu Lake. Research Journal of Fisheries and Hydrobiology. 2010;5(1):1–8. [Google Scholar]
  11. Morey G, Moranta J, Massuti E, Grau A, Linde M, Riera F, Morales-Nin B. Weight-length relationships of littoral to lower slope fishes from the Western Mediterranean. Fisheries Research. 2003;62(1):89–96. [Google Scholar]
  12. Moutopoulos DK, Stergiou KI. Length-weight and length-length relationships of fish species from Aegean Sea (Greece) Journal of Applied Ichthyology. 2002;18(3):200–203. [Google Scholar]
  13. Pervin MR, Mortuza MG. Notes on length-weight relationship and condition factor of freshwater fish, Labeo boga(Hamilton) (Cypriniformes: Cyprinidae) University Journal of Zoology, Rajshahi University. 2008;27:97–98. [Google Scholar]
  14. Ricker WE. Methods for assessment of fish production in freshwaters. Oxford, UK: Blackwell Scientific Publications; 1968. [Google Scholar]
  15. Sinovcic G, Franicevic M, Zorica B, Ciles Kec V. Length-weight and length-length relationships for 10 pelagic fish species from the Adriatic Sea (Crotia) Journal of Applied Ichthyology. 2004;20:156–158. [Google Scholar]
  16. Velasco G, Oddone MC. Growth parameters and growth performance indexes for some populations of marine catfishes (Actinopterygii, Siluriformes, Ariidae) Acta Biologica Leopoldensia. 2004;26(2):307–313. [Google Scholar]

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