Mejri, Sahar

The distribution and intensity of hypoxia (low dissolved oxygen, DO) is increasing due to eutrophication and algal blooms in estuaries like those in the Gulf of Mexico and the Indian River Lagoon. The objective of this study is to determine how low DO affects the development and lipid utilization of the Florida Pompano (Trachinotus carolinus) and Red Drum (Sciaenops ocellatus). Fertilized eggs were incubated in two DO hypoxia treatments: severe (20% DO saturation, 1.6 mg/L), moderate (50% DO saturation, 3.9 mg/L), and normoxia (100% DO saturation, 7.6 mg/L). Eggs and larvae were sampled at 24-hours post-fertilization to assess hatch survival, larval development, and fatty acid (FA) lipids utilization. Results suggest hypoxia significantly impacts Florida Pompano development, with polar FAs most affected, while Red Drum shows greater tolerance to low DO. These findings provide insight into early fish larval stages to improve conservation and management strategies for their recruitment.

Existing brood fish research has ascertained that eggs are heavily influenced by broodstock diet but there is no information regarding this timeline of nutritional incorporation. The objective of this study is to determine duration of nutritional incorporation from diet to eggs through fatty acids. Nine California Yellowtail (Seriola dorsalis) broodstock were fed alternating diets of commercial pellets (Vitalis PRIMA: Skretting) and cutbait. Biochemical and biometric data from spawns were collected and analyzed for differences and similarities throughout the alternating diets. Eggs were observed to selectively incorporate higher sources of linolenic and linoleic acid from the pelleted diet, and eicosapentaenoic acid from the cutbait diet. Interestingly, results showed overall fatty acids from both diets were fully incorporated by eggs within 9 days following the diet switch. These findings provided new insight towards the selective incorporation of nutrients and will open new doors for future broodstock nutrition research.