Lifetime energy budget in the sea hare Aplysia oculifera

We studied energy budget and resource allocation through the entire postmetamorphic life span, under controlled laboratory conditions, in the sea hare Aplysia oculifera from the Red Sea. Growth of sea hares was according to the Gompertz equation: Body live mass (BLM) t = 105 exp[- exp{ - 0.053(t - 43.04)}]. Maximum postmetamorphic life span was 162 days. Sea hares began to spawn at 8 g BLM. Egg production (Pr) was related to BLM by the equation Pr(egg live mass, g · d^-1 · ind^-1) = 0.0048(BLM)^1.32. Oxygen consumption rates of sea hares at 24 ± 0.5°C were related to BLM by the equation V_O2(ml · ^h-1 · ind^-1) = 0.111(BLM)^0.78. Food consumption (C) and feces production (F) were related to BLM by the equations C(g dry mass · d^-1 · ind^-1) = 0.063(BLM)^0.84 and F(g dry mass · d^-1 · ind^-1) = 0.047(BLM)^0.44, respectively. The results were transformed to energetic values, and energy budget and resource allocation of the sea hares were calculated. A. oculifera invested 8-16% of the absorbed energy in metabolism (respiration). At BLM < 8 g, all the remaining energy was used for growth. From 8 g BLM on, sea hares began to reproduce and the energy allocated for reproduction increased with BLM, while the energy allocated for growth decreased. Growth stopped at mean BLM of 105 g. Comparison of the results with field data suggest high potential productivity that usually is not utilized in the field.