Temperature-Dependent Feed Consumption Patterns for Greenlip (Haliotis laevigata) and Hybrid (H. laevigata × Haliotis rubra) Abalone Fed Fresh Macroalgae or a Formulated Diet

ABSTRACT Because of the nocturnal and slow feeding activity of abalone, farmed abalone are typically provided with feed throughout the night. Understanding the nocturnal feeding patterns of abalone is fundamental to feed management and productive abalone farming. In this study, the apparent feed consumption for greenlip abalone (Haliotis laevigata) and hybrid abalone (H. laevigata3Haliotis rubra) fed fresh Ulva sp. or a commercial formulated diet at 18°C or 22°C were investigated at night. Abalone were exposed to low light intensity (3.4 Lux) from 7:00 AM to 7:00 PM and darkness from 7:00 PM to 7:00 AM. Abalone were fed to excess daily at 4:00 PM and feed intake was determined at 7:00 PM, 10:00 PM, 1:00 AM, 4:00 AM, and 8:00 AM. When Ulva sp. was added to the tank, greenlip and hybrid abalone immediately displayed a feeding response, which was not observed in abalone fed the formulated diet. Abalone consumed Ulva sp. at a linear rate from 4:00 PM to 8:00 AM. In contrast, the apparent feed consumption rate...