Optimum weaning method for pharaoh cuttlefish, Sepia pharaonis Ehrenberg, 1831, in small‐ and large‐scale aquaculture

Abstract

Two scale trials were conducted to determine the optimum weaning protocols cuttlefish (Sepia pharaonis) juvenile for understanding the feeding habits of cuttlefish and the development of effective aqua‐cultural practices. Three experimental weaning protocols (i.e. cuttlefish size, feeding frequency and culture density) on the growth, survival and muscle proximate composition of cuttlefish juveniles were performed in a small‐scale trial. Then, the optimal weaning protocols were applied to a large‐scale trial for validation. The weaning period lasted 2 weeks. The results showed that larger individuals showed better growth performance than smaller individuals, especially in terms of juvenile survival and specific growth rate (SGR), indicating that larger individuals were more receptive to frozen prey. Increased feeding frequency did stimulate the appetite of animals raised during feeding conversion, and enhance survival, growth and protein deposition compared to low feeding frequency. Moreover, the weight gain (WG) and SGR in the 60 and 70 cuttlefish/m2 culture density groups were much higher than those in the 80 cuttlefish/m2 group; however, there was no significant difference in survival among the culture density groups. The validation results of optimal weaning protocols in the large‐scale trial indicated that, according to growth performance, the optimum culture density for juvenile cuttlefish weaning was 70 cuttlefish/m2. These results indicate that the optimal weaning protocols for cuttlefish juvenile are as follows: a dorsal mantle length of 24.0 mm or more, the feeding frequency of 4 meals/day and the culture density of 70 cuttlefish/m2. These findings have important implications for understanding the feeding habits of cuttlefish and for the development of effective aqua‐cultural practices.

Potential Plasticity of Artificial Feed Preference in Juvenile Pharaoh Cuttlefish (Sepia pharaonis) Through Progressive Training Programs

“…As a member of the cephalopod family, the pharaoh cuttlefish has been proven to have number sense and excellent learning ability (Yang and Chiao, 2016;Yasumuro and Ikeda, 2018;Huang et al, 2019). Studies have verified several methods of pharaoh cuttlefish weaning, providing us with reliable message training methods that enable cuttlefish to become accustomed to eating artificial feed (Jiang et al, 2018(Jiang et al, , 2020(Jiang et al, , 2021. Our cultural experience (we weaned more than 5000 juveniles per year between 2015 and 2021) suggests that the key challenge is not the weaning process but the reduction of rearing cost and preparation of nutritional diets.…”

“…Studies have reported positive results after feeding surimi to S. officinalis and highlighted that the protein content of the mantle muscle is a valuable indicator in long-term rearing (Castro et al, 1993;Castro and Lee, 1994). Numerous studies have reported that the higher the percentage of protein (35-50%) in an artificial diet, the better the growth performance of the fed cuttlefish (Domingues et al, 2005(Domingues et al, , 2008Ferreira et al, 2010;Gao et al, 2014;Han et al, 2017;Jiang et al, 2021). Some studies have highlighted the crucial role of fatty acids for cuttlefish, particularly eicosapentaenoic acid and docosahexaenoic acid, with cuttlefish requiring high amounts of these nutrients (Perrin et al, 2004;Ferreira et al, 2010;Gao et al, 2014;Wen et al, 2014;Jiang et al, 2018).…”

“…Although pharaoh cuttlefish can be reared for multiple generations, its mass production remains difficult. Jiang et al (2021) proposed an optimum weaning method for pharaoh cuttlefish in mass culture and a specific culture protocol. However, the high cost and unstable quality of the live or fresh diet required for rearing pharaoh cuttlefish limit their mass production (Han et al, 2017;Jiang et al, 2018).…”

Effects of feed transition on digestive tract digestive enzyme, morphology and intestinal community in cuttlefish (Sepia pharaonis)

“…Frozen food was provided to juveniles from 30 DPH, following previously prescribed weaning protocols (Jiang et al, 2021). We followed the optimal weaning protocols, with the ideal prepared food of frozen shrimp (Leptochela gracilis), the feeding frequency was 4 meals d -1 , the food ratio was 35% b.w.day -1 , and the culture density was 70 cuttlefish m -2 .…”

“…Cuttlefish accept frozen food (shrimp, fish, or crabs) after the initial hatchling stage (DeRusha et al, 1989;Forsythe et al, 1994;Jiang et al, 2018). Our latest research on optimal weaning protocols for cuttlefish juveniles has validated this on a commercial scale and represents a major step towards improving rearing techniques for S. pharaonis (Jiang et al, 2021). However, the dynamic changes in the digestive gland and the adaptability of the intestine from pre-feed transition to post-feed transition remain largely unexplored.…”