Interaction of temperature and photoperiod on growth of Atlantic halibut Hippoglossus hippoglossus L.

Abstract

The combined effect of temperature and photoperiod on the growth of juvenile Atlantic halibut Hippoglossus hippoglossus (initial weight 11.6 g) was investigated under different temperature (6 °C and 12 °C) and photoperiod (continuous light and simulated natural photoperiod) combinations by studying the effects on fish weight, specific growth rate (SGR), feed consumption (F%), feed conversion (FCE) and oxygen consumption and ammonia excretion under routine and fasting conditions. SGR was greater at the higher temperature, and growth was faster under continuous light than under natural photoperiod, irrespective of temperature, SGRs being 0.83% and 0.98%, and 1.61% and 1.71% at 6 °C and 12 °C respectively. The weight data revealed a significant interaction between temperature and light, and provided evidence of a stronger growth‐enhancing effect of continuous light at the lower temperature. F% increased with temperature but was independent of photoperiod, whereas FCE was higher among fish exposed to continuous light, irrespective of temperature. Independently of photoperiod, oxygen consumption and ammonia excretion increased with temperature, but the differences in these rates in relation to photoperiod became more pronounced at the lower temperature, where continuous light gave the highest rates. Higher oxygen consumption during darkness suggested that light may suppress activity in halibut. It was proposed that reduced activity and anabolic effects of photoperiod contribute to explain the increased growth and growth efficiency in fish subjected to continuous light.

The effect of temperature and fish size on growth of juvenile lumpfish (Cyclopterus lumpus L.)

“…This causes more developed specimens to allocate energy mainly for maintenance purposes (R maint ), while younger have a larger capacity for distributing energy towards growth. At higher temperatures the increased metabolic rates will eventually exceed that of possible gain by the means of increased food intake (Hallaraker et al 1995;Jonassen et al 2000b) which in the end will reduce the final possible growth rate (Jonassen et al 1999). These factors yield the dome shaped curve for T opt FCE and T opt SGR observed for juvenile fish of several marine species (Fonds et al 1992;Bjornsson & Tryggvadottir 1996;Jonassen et al 1999;Otterlei et al 1999;Bjornsson et al 2001;Imsland et al 2005;Imsland et al 2006).…”

“…Despite consistency in the findings of increased final weight with increasing temperature, these comparisons of final weight between studies do not take into consideration possible effects of different photoperiods (Jonassen et al 2000b;Imsland & Jonassen 2001;Lohne et al 2012), feeding regimes (Brown et al 1997) and time scopes (Björnsson et al 2007;Arnason et al 2009). …”

“…The fish used in both experiments were graded according to weight prior to the experiment (TABLE III, Appendix II) to reduce the effects of size hierarchies on feeding and growth, as observed in previous studies of juvenile lumpfish (Hallaraker et al 1995;Killen et al 2007) and other juvenile marine fish (Hallaraker et al 1995;Imsland et al 1996;Aune et al 1997;Jonassen et al 2000b;Imsland et al 2005). Results from size ranking (initial versus final weight) indicate that size hierarchies in fact did form in all groups of experiment 1 (TABLE LX, Appendix II), but it is unknown to which extent this may have had an effect on growth and feeding behavior.…”

“…Temperatures have a secondary effect in terms of increasing oxygen consumption at high temperatures (Hallaraker et al 1995;Jonassen et al 2000b), and causes energy costs to decrease at continuous light and at lower temperatures (Imsland & Jonassen 2001). In terms of feed costs a maximum-and maintenance ration (R max and R maint , respectively) can be established, defining the available energy for somatic growth and metabolic functions.…”

Manipulation of photoperiod in growth factors of beluga sturgeon Huso huso

“…In addition to temperature, photoperiod is an important factor that affects living organisms including fishes. Effects of photoperiod on growth rate and other variables has been studied in various species (Saunders and Harmon, 1988;Krakenes et al, 1991;Imsland et al, 1995;Davis et al, 1999;Jonassen et al, 2000;Kissil et al, 2001;Petit et al, 2003;Trippel and Neil, 2003;Norberg et al, 2004;Bayarri et al, 2004;Blancas-Arroyo et al, 2004;Taylor et al, 2006;Valenzuela et al, 2006;Bonnet et al, 2007;Ruchin, 2007). Very little information exists regarding effects of photoperiods on growth of beluga Huso huso, especially considering the species is the most commonly cultured sturgeon in Iran and its caviar as the most expensive product in the world.…”