The dietary substitution effect of fishmeal (FM) with tunic meal of sea squirt (SS) on growth and body composition of juvenile abalone, Haliotis discus, was evaluated. A total of 1470 juvenile abalone were distributed into 21 70‐L plastic rectangular containers. Six experimental diets in triplicate were prepared, and 20% FM was included in the FM0 diet. The treatments consisted of 20, 40, 60, 80, and 100% of FM substituted with tunic meal of SS, referred to as the FM20, FM40, FM60, FM80, and FM100 diets, respectively. Undaria was also prepared to compare the effect of the formulated diets on performance of abalone. The experimental diets were fed to abalone once a day at a satiation level for 16 wk. Weight gain of abalone fed the FM0 diet was higher than that of abalone fed the FM100 diet and Undaria, but not different from that of abalone fed the FM80 diet. Crude protein, crude lipid, and ash contents of the soft body of abalone fed all formulated diets were higher than those of abalone fed the Undaria diet. In conclusion, FM up to 80% could be replaced with tunic meal of SS without retardation in growth of abalone. The best growth was obtained in abalone fed the FM20 diet.

Olive flounder, Paralichthys olivaceus, is one of the highest valued finfish species for aquaculture in Korea, Japan and China due to its good flavour and excellent growth. Its annual aquaculture production in 2018 ranked the highest (43,245 metric tons) among the annual production of marine finfish in Korea (KOSIS, 2020). To date, many feeding trials, such as dietary protein and lipid re

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Effects of dietary inclusion of yacon, Polymnia sonchifolia (YC), ginger, Zingiber officinale (GG), and blueberry, Vaccinium ashei (BB), on growth, body composition and challenge test of rockfish against Edwardsiella tarda compared to ethoxyquin were investigated. Three hundred and sixty fish were randomly distributed into 12 flowthrough tanks. Four experimental diets were prepared: the control diet (Con) with 0.1 g/kg ethoxyquin, and YC, GG and BB diets. Each diet was assigned to triplicate tanks of fish and hand-fed for 8 weeks. Externally normal fish after fourth and eighth weeks of feeding trial were infected with Edwardsiella tarda for challenge test. Weight gain and specific growth rate (SGR) of fish fed the YC diet were greater than those of fish fed all other diets. Feed efficiency, protein efficiency ratio and protein retention of fish fed the YC diet were higher than those of fish fed all other diets. In the both fourth and eighth weeks of infection trials, mortality of fish fed the Con diet was higher than that of fish fed all other diets. In conclusion, dietary inclusion of YC, GG and BB increased weight gain and SGR of fish. YC, GG and BB for 4 and 8 weeks lowered mortality of fish at occurrence of E. tarda. K E Y W O R D Sblueberry, challenge test, Edwardsiella tarda, ginger, rockfish (Sebastes schlegeli), yacon

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Substitution effect of white radish' by-product (WRB) and tunic of sea squirt (TSS) for Undaria in feed on growth and carcass composition of abalone was determined. Eight-hundred forty juveniles were distributed into 12 containers. Three formulated diets were prepared in triplicate. A 15% Undaria was included in the control diet. The 15% Undaria was substituted with a same amount of WRB and TSS, referred to as the DRG and TSS diets, respectively. Finally, dry Undaria was also prepared to compare effect of the formulated diets on performance of abalone. The experimental diets were fed to abalone once a day at a satiation level with a little leftover. The feeding trial lasted for 16 weeks. Crude protein, crude lipid, and ash content of the experimental diets changed over all period of time. Higher crude protein and lipid and ash contents retained in all formulated diets compared to the Undaria were observed at 24 and 48 h after seawater immersion. Survival of abalone was not affected by the experimental diets. Weight gain and specific growth rate (SGR) of abalone fed the TSS diet was greater than all other diets. Weight gain and SGR of abalone fed the control diet was not different from those of abalone fed the WRB diet. Proximates of the soft body of abalone was affected by the diets. In conclusion, WRB and TSS are the promising feed ingredients to replace Undaria in abalone feed; especially, TSS is superior to either Undaria or WRB. The formulated diets produced improved growth performance of abalone over the single Undaria.

The effects of fish meal (FM ) and macroalgae (M A) substitution with fermented soybean meal and rice bran were tested on a commercial diet in juvenile abalone. Abalone (21600) individuals were distributed equally to four diet treatments. Four experimental diets were prepared: a Std diet, FM 50, FM50+M A50 and FM50+MA100. The standard diet (Std) consists of FM (140 g/kg), fermented soybean meal (250 g/kg), corn gluten meal (34 g/kg), shrimp meal (30 g/kg), wheat flour (200 g/kg), dextrin (50 g/kg) and M A (250 g/kg). Undaria and Laminaria were also prepared. The feeding trial lasted for 16 weeks. Survival of abalone fed the formulated diets was higher than that of abalone fed the Undaria and Laminaria. Weight gain and specific growth rate of abalone fed the Std diet were higher than all other diets. Substitutability of the fermented soybean meal for FM seemed to be rather limited in the commercial diet for abalone farms. However, another 500 g/kg M A in the commercial diet could be substituted with rice bran as long as 500 g/kg M A were substituted with rice bran. The FM 50+M A50 diet is the most recommendable for abalone farm in considering feed cost.