Effect of salinity on metabolism and growth in juvenile flounder Paralichthys adspersus

Acuache-Villegas A.V.; Francia-Quiroz J.C. · Marine and Fishery Sciences (2026) · DOI: 10.47193/mafis.3932026010705

Resumen

Salinity is a key environmental factor influencing osmoregulatory processes and energy metabolism in marine fish; however, in euryhaline species such as Paralichthys adspersus, the magnitude of these effects on metabolism and somatic growth during juvenile stages remains insufficiently understood. This energetic cost, essential for maintaining homeostasis, not only regulates metabolic rate but may also affect key biological functions such as growth, reproduction, and immune response. The effect of salinity (16 and 33) on aerobic metabolism and somatic growth was evaluated in juvenile P. adspersus, classified into three body size categories (small, medium, and large). Fish were cultured for 30 days under a 3 × 2 factorial design (size × salinity), and individual oxygen consumption (COI), specific oxygen consumption (CEO), weight gain (GP), specific growth rate (TCE), condition factor (K), and survival were assessed. The COI did not show significant differences between salinity levels (F1.10 = 0.844; p = 0.379), but increased significantly with body size (F2.10 = 6.906; p = 0.006). The CEO did not differ significantly as a function of salinity or size (p > 0.05), although a decreasing trend with increasing body mass was observed. Body weight was significantly influenced by culture time (p < 0.001) and size (F2.53 = 111.53; p < 0.001), while salinity had no significant effect (F1.53 = 2.566; p = 0.115). The GP and TCE showed no significant differences as a function of salinity or size (p > 0.05), although slightly higher values were observed at 16. The condition factor remained stable and survival reached 100% in all treatments. Overall, results indicate that the evaluated salinity does not significantly affect aerobic metabolism or somatic growth in juvenile P. adspersus, whereas body size represents the main determinant of individual metabolic rate and growth performance.

Instituciones: Universidad Científica del Sur