LENGTH-WEIGHT RELATIONSHIP AND CONDITIONAL FACTOR OF 16 IMPORTANT FISH SPECIES IN THE MEKONG DELTA, VIETNAM

The length-weight relationship (LWR) constitutes a fundamental analytical tool in ichthyological research, facilitating the assessment of growth dynamics, health status, and morphometric variations within fish communities. The present investigation was conducted to analyze the LWRs of economically and ecologically important fish species, which are predominantly exploited by small-scale fisheries within the Mekong Delta, Vietnam. Between January 2019 and March 2020, a total of 1,546 specimens, encompassing 16 species across 11 taxonomic families, were systematically collected. Morphometric data, specifically total length (TL) and body weight (W), were meticulously recorded for each individual, and sex was identified wherever feasible to enhance biological interpretation. The length-weight relationship was estimated using the equation W=a*TLb, where a and b represent species-specific constants. To enable statistical inference, a logarithmic transformation was applied, yielding a linear form: log(W) = log(a) + b*log(TL), which was subsequently analyzed using least-squares linear regression. All length-weight relationships deviations fell within the range of 2.72 to 3.28, of which eight species exhibited positive allometry (b > 3), seven species demonstrated negative allometry (b < 3), and one species showed isometric growth (b = 3). In addition, Fulton’s condition factor (K) was utilized as an indicator of fish health status. With the exception of two species from the genus Coilia, all estimated fish species showed comparatively high K-values, suggesting a generally favorable physiological condition among the studied fish populations. Collectively, these results highlight the overall health resilience and adaptive potential of fish communities inhabiting the dynamic aquatic habitats of the Mekong Delta.