The Effect of Feed Frequency on Growth, Survival and Behaviour of Juvenile Spiny Lobster (Panulirus ornatus)

Abstract

Spiny lobsters have a range of complex chemical communication pathways that contribute to feeding behaviour. Feed intake is modulated by feed availability and feed characteristics, such as attractiveness and palatability, with behavioural factors, such as social competition and circadian rhythm, providing an extra layer of complexity. In this study, we investigated the effect of feed frequency on survival and growth of early-stage (instar 2–6) juvenile Palunirus ornatus. In addition, we investigated the interactive effect of feed frequency and circadian rhythm on lobster feed response. Lobsters were fed a set ration at a frequency of either one, two, four, eight, sixteen or thirty-two times per day over 49 days. The effect of feed frequency on growth and survival was determined. Circadian feeding activity under these feeding treatments was assessed by time-lapse photography. Increased feed frequency from one to sixteen feeds daily improved growth by increasing apparent feed intake (AFI) and feed attraction, as confirmed by the increased presence of lobsters in the feeding area. The rapid leaching of feed attractant, particularly free amino acid, suggests a beneficial effect of multiple feeding frequencies on feed intake and growth. However, more than sixteen feeds per day resulted in decreased feed intake and a subsequent reduction in growth. The decrease in feed intake is thought to be associated with saturation of the culture environment with attractants, resulting in a reduced behavioural response to feed supplies. This may indicate the need for depletion of attractants to retrigger a feeding response. As lobsters were grown communally, faster growth at sixteen rations per day was also coupled with increased cannibalism, likely driven by increased vulnerability with the occurrence of more frequent ecdysis events. Whereas circadian rhythm indicated more activity at night, an interaction between daytime activity and feed frequency was not observed.

Feeding management and appraisal of recirculating aquaculture system for spiny lobster Panulirus spp. weaning

“…Panulirus versicolor exhibited improved carapace length when fed four times, suggesting a recommendation for more night feeding due to its nocturnal behavior [10]. On the other hand, Panulirus ornatus showed increasing growth from one feeding session to sixteen feeding sessions throughout the day [11]. An unresolved issue in our study is the unidentified species of lobster fries, which hinders the analysis of each species' behavior.…”

“…In this research, examples of such ingredients include astaxanthin, cholesterol, and MOS (mannan oligosaccharides). Studies have shown that in adult P. ornatus, the highest concentration of astaxanthin and lower concentration of cholesterol result in optimal growth [11]. While these ingredients do not directly affect the growth and survival of P. ornatus in the juvenile stage, their accumulation in the lobster's body can enhance immunocompetence and potentially increase market price [12].…”

Effect of Feed Texture and Dimensions, on Feed Waste Type and Feeding Efficiency in Juvenile Sagmariasus verreauxi

“…Future research in feed development for juvenile lobsters should investigate solutions to improve feed intake by prolonging the attractiveness of feeds. Although, utilising multiple feeding frequencies of the feed ration may represent a good strategy to keep feed attractive over time and thus, promote feed intake [25].…”

Development of a two-current choice flume behavioural bioassay for juvenile Panulirus ornatus response to moulting cues

“…Additionally, we have seen inter-moult juveniles showing attraction to naïve moulting cues. This may imply an interest in locating the source, as attraction to cues can often correlate with an increase in foraging activity, consumption of exuvia and possibly cannibalism 24 , which is commonly observed in communally housed spiny lobsters 22 , 57 , 58 .…”