This study investigates the impact of fishmeal replacement by soybean meal (SM) and improved SM known as EnzoMeal (EZ) on fish growth performance. The SM and EZ were used in five experimental diets: fishmeal (600 g/kg) as the control diet, 50% fishmeal replaced with soybean meal (SM50), 50% fishmeal replaced with EnzoMeal (EZ50), 100% fishmeal replaced with soybean meal (SM100) and 100% fishmeal replaced with EnzoMeal (EZ100). Fish in the control group gained the most weight, followed by those under the SM50 and EZ50 diets, while the least weight gain was observed in fish fed the SM100 and EZ100 diets. The specific growth rate (SGR) was higher in the control, but was not different between fish fed SM50 and EZ50, or between SM100 and EZ100. The highest feed intake occurred in the control but decreased sequentially from fish fed SM50 to fish fed EZ50, EZ100 and SM100. Protein digestibility was best in SM50, poorest in EZ100, but no difference between the control, EZ50 and SM100 diets. This study indicates that EnzoMeal, containing high crude protein (56%), is a potential source of plant meal to replace fishmeal in the barramundi diet, but low feed intake is a challenge when EnzoMeal is >300 g/kg. K E Y W O R D Sbarramundi Lates calcarifer, EnzoMeal, fishmeal replacement, rearing performance, soybean meal

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Carbon dioxide levels in many estuaries fluctuate and, in several cases, reach extremes much higher than those predicted for oceans by the end of the century. Moreover, estuaries are characterized by natural fluctuations in salinity, and reduced pH, from increased pCO 2 , exposes estuarine organisms to multiple stresses. Although the effects of low pH on the reproduction of several marine copepod species have been assessed, studies examining effects of pH in estuarine copepod species are extremely scarce. Here, we aim at understanding the reproductive response of Gladioferens pectinatus to the stress posed by both salinity and pH. G. pectinatus was exposed to salinities 2 and 10, at four different pH levels each. Our results show no impairment in the brood size, embryonic development time and hatching success under low pH levels at either salinities. However, at salinity 2, the percentage of nauplii growing into adults significantly decreased at low pH, whereas at salinity 10, no major effect was observed. We argue that the combination of osmoregulation and acidity induced stress response can affect the development of nauplii and copepodites, as well as adult recruitment, likely due to energy reallocation and molting impairment. We also argue that resilience and phenotypic plasticity highly influence the ability of different copepod species and populations to reproduce and grow under stressful combinations of environmental parameters. This study points out the importance of understanding the effects of multiple stresses or parameters on the adaptability of organisms to water acidification.