International Journal of Aquaculture, 2025, Vol.15, No.6, 275-286 http://www.aquapublisher.com/index.php/ija 283 3.5 Implications for fisheries management The length–weight relationship (LWR) revealed that Ethmalosa fimbriata mostly exhibited negative allometric growth, meaning weight increased more slowly than length, while Chrysichthys macropogon showed a mix of isometric and positive allometry depending on location. Growth constants varied with season and site, reflecting environmental influences. Higher b-values at Bijimi and Idiogba suggest better feeding conditions and reduced fishing stress, whereas lower values at Asumogha point to environmental pressures or resource limitations (Adepoju et al., 2023; Oladipo et al., 2023; Ibrahim et al., 2024). 4 Discussion The morphometric analysis showed notable disparities in the length and weight of Ethmalosa fimbriata and Chrysichthys macropogon across the four sampling sites shows a clear evidence of environmental variability shaping growth in Ilaje LGA (Oladipo et al., 2023; Yakubu et al., 2023). For E. fimbriata, lengths varied from 16.72 ± 4.40 cm at Bijimi to 20.20 ± 4.94 cm at Idiogba, with weights ranging from 62.18 ± 34.30 g to 92.78 ± 52.31 g, respectively. Larger sizes at Idiogba suggest better habitat quality and reduced fishing pressure, whereas smaller fish at Bijimi may reflect high human disturbance or diminished prey availability (Ekunwe et al., 2021). For C. macropogon, length spanned 16.82 ± 4.97 cm (Asumogha) to 19.19 ± 6.53 cm (Idiogba), with weight ranging from 65.28 ±41.28 g to 94.94 ±57.49 g at Bijimi, underlining site-driven growth dynamics influenced by water quality and anthropogenic stressors (Bolarinwa and Popoola, 2022; Oladipo et al., 2023). Allometric growth patterns were evident in both species: E. fimbriata b-values ranged from 1.09 to 2.68, indicating negative allometry, often a response to environmental stress or limited feeding (Adepoju et al., 2023); C. macropogon showed a broader range (1.56~3.18), indicating both negative and positive allometry depending on habitat conditions. Positive allometry suggests favorable feeding or reduced competition, while negative indicates stress or resource limitation—textbook predictors of fish growth in heterogeneous tropical environments (Etim et al., 2020). Condition factors (K) further supported this: E. fimbriata ranged from 0.92 to 1.56, and C. macropogon from 0.74 to 1.70. Higher K values at Idiogba and Bijimi imply healthier fish in better habitats; lower values at Asumogha point to environmental stress, possibly from pollution or habitat degradation (Ibrahim et al., 2024). These results reinforce K as a reliable bioindicator of fish health (Oladipo et al., 2023; Ibrahim et al., 2024). These patterns support the assertion that environmental stressors such as oil residues, nutrient loading, and heavy metal contamination impair fish health and condition (Nwani et al., 2020; Ayanda et al., 2022). Pollutant exposure reduces feeding efficiency and energy allocation, leading to lower growth performance and condition factors. Negative allometric growth observed in both species indicates that energy is diverted toward survival and detoxification rather than somatic growth (Okomoda et al., 2021). Such findings are consistent with studies in other polluted Nigerian waters, where fish in degraded habitats show reduced condition compared to those in cleaner environments (Oladimeji and Akinyemi, 2023; Musa and Yakubu, 2024). This highlights that LWR and K are sensitive indicators of ecological stress and can be employed for rapid assessment of aquatic ecosystem health. Overall, the combined morphometric, LWR, and condition factor data clearly illustrate how environmental variation influences fish growth and condition. Idiogba consistently supported healthier, larger fish, whereas Asumogha showed signs of ecological stress insights crucial for guiding habitat restoration and fisheries management in Ilaje coastal waters. 5 Conclusion This study demonstrated that pollution significantly influences growth patterns and condition factors of E. fimbriata and C. macropogon in Ilaje waters. The lowest K values were recorded at Idiogba (0.74 and 0.92), while the highest
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