Shelter selection by juvenile Pacific abalone ( Haliotis discus hannai Ino) as a function of food distribution and water flow velocity

Abstract

Juvenile Pacific abalone (Haliotis discus hannai Ino) are currently reared in land‐based aquaculture systems until they reach the necessary size for seeding in the sea. One problem that this industry faces is that an uneven distribution of juveniles in tanks can lead to variations in the growth rate. Understanding the cues that affect the sheltering behaviours exhibited by juvenile Pacific abalone—namely, the food distribution and the water flow velocity—will help optimize abalone culture settings. In this study, a group of 1,000 juvenile Pacific abalone (distributed across three tanks) was visually observed and enumerated during six experiments that were conducted over a 5‐month study period. It was found that juvenile Pacific abalone preferred to shelter close to food sources when the food was unevenly distributed. When the food was evenly distributed, the juveniles tended to avoid areas of rapid water flow and distributed evenly across the sheltered areas receiving the equal water velocity. This distribution might be the confounding effects between water flow velocity and food stimulus. Based on these findings, it was recommend that the food and water velocity be evenly distributed in an abalone aquaculture system.

A review of influencing factors on a recirculating aquaculture system: Environmental conditions, feeding strategies, and disinfection methods

“…In natural environments, fish are sensitive to flow rates of water and will choose areas with proper flow rates to reduce energy consumption (Hockley et al, 2014). Meanwhile, the appropriate flow rate is beneficial to improve the growth rate, survival rate, feeding ability, and environmental adaptability of fish (DePasquale & Leri, 2018; Hou et al, 2020; Li, Ji, et al, 2019; Li, Yang, et al, 2019; Mrnak et al, 2020). The differences in living habits and ecological niche determine the difference of organism requirements for optimal flow rate (Domenici et al, 2008).…”