Optimal feeding frequency for bigfin reef squid (Sepioteuthis lessoniana)

Abstract

Bigfin reef squid (Sepioteuthis lessoniana) has been successively cultured through multiple generations, but little is known about the factors affecting feeding regimens. In the current study, optimal feeding frequency of five‐week‐old bigfin reef squids was investigated in laboratory conditions. The squids (1.48 ± 0.03 g initial weight) were assigned to four feeding frequencies: two (2TD), three (3TD), four (4TD) or five (5TD) times daily, and they were fed with post‐larval stage of Pacific white shrimp (Litopenaeus vannamei) over the three weeks of experiment. At the end of the feeding trial, the squids receiving 4TD and 5TD had the highest growth and feed utilization, and the least size variation among the treatment groups. Significant decrease in chymotrypsin‐specific activity was observed in squids receiving 5TD relative to 2TD (p < 0.05), while a moderate level was observed across the remaining treatments. This matched the available and unavailable nutrients present in faeces, assessed from thermal responses. Mantle quality, in terms of RNA concentration, was the highest in squids fed 4TD or 5TD, while protein concentration and RNA/protein ratio did not differ across the four feeding frequencies tested. Also, the most crude lipid was observed in squids fed 5TD, followed by 4TD that were superior to 2TD or 3TD treatments, while crude protein and ash did not differ. These findings indicate that feeding four or five times daily is most appropriate. This practical feeding protocol can be used for mariculture of this species.

Effects of Rearing Density, Substrate Height, and Feeding Frequency on Growth and Biomass Production of Hediste diversicolor

“…a clear pattern was not found for medium and large worms; in any case, the frequency of three times per week could be used to optimize labor without major effects on growth or survival. To date, this aspect has not been studied in worms, but some works have investigated this in other invertebrates, such as reef squid juveniles [26] or sea cucumber juveniles [24], for which feeding frequency affects growth and coefficients of variation. We found no differences in CV, which may be due to the short cultivation period.…”

“…Feeding frequency modulates aggression and cannibalism in aquatic animals [25]. The optimal feeding frequency may vary according to age, size, feed quality, water temperature, and culture system [23,26]. Different feeding frequencies have been applied in H. diversicolor [4,9,16,18,19] but not experimentally investigated.…”