Consumption, absorption efficiency, respiration and excretion in the South African abalone haliotis midae

Abstract

Feeding periodicity, consumption rate, absorption efficiency, respiration rate and ammonia excretion were measured as functions of wet body mass in abalone collected from the western and southern Cape coasts. A well developed diel feeding rhythm was evident, consumption being restricted to the period 16h00–08h00. Food intake averaged 8, 1 per cent of wet flesh mass·d−1 at 14°C and 11, 4 percent at 19°C. The daily consumption rate was related to body mass by the relationships C(g) = 0, 54 W(g)0, 67 at 14°C and C(g) = 0, 35 W(g)0, 77 at 19°C. Absorption efficiency averaged 37 per cent and was independent of body size. Equations relating respiration rate to wet body mass were R(mℓ O2·h−1) = 0, 03 W(g)0, 83 at 14°C and R = 0, 03 W(g)0, 94 at 19°C. No significant differences were detected between day and night rates or between fed and starved individuals. The rate of ammonia excretion (μmole·h−1) was related to wet body mass (g) by the equations U = 0, 22 W0, 43 at 14°C and U = 0, 03 W0, 85 at 19°C. © 1987 Taylor & Francis Group, LLC.