Optimal dietary methionine requirement for juvenile sea cucumber Apostichopus japonicus selenka

Abstract

This trial was conducted to determine the optimal dietary methionine requirement for juvenile sea cucumber Apostichopus japonicus selenka. Six isonitrogenous and isoenergetic experimental diets were formulated with graded methionine levels (0.18%, 0.37%, 0.57%, 0.78%, 0.96%, 1.10% dry matter). Each diet was assigned randomly to triplicate groups with 30 sea cucumbers juveniles with initial body weight 12.14 g in a recirculated aquaculture system for 56 days. Survival rate was not affected by dietary methionine. With the increase of dietary methionine levels, both weight gain and specific growth rate were significantly increased initially and then decreased afterwards. Both crude protein and crude lipid contents of body wall were evaluated firstly and dropped afterwards. meanwhile, contents of methionine, cystine, aspartic acid and total amino acids of body wall were all increased. Both total antioxidant capacity and total superoxide dismutase activities of intestine were increased, while malondialdehyde contents were decreased with the increase of dietary methionine. All of activities of protease and lipase were increased initially and then decreased afterwards; however, there was no significantly effect on amylase. In conclusion, analysis by a linear regression equation of WG or methionine contents in body wall indicated that the optimum requirement of methionine for juvenile sea cucumber (initial body weight 12.14 g) was 0.58%–0.72% diet (2.77%–3.42% diet protein).

Influence of Dietary Phosphorus on the Growth, Feed Utilization, Proximate Composition, Intestinal Enzymes, and Oxidation Resistance of Sea Cucumber Apostichopus japonicus

“…The predicted dietary phosphorus level is 0.63% for maximum growth. Aquaculture Nutrition compared to the growth data from other studies [17,[48][49][50]. These positive growth responses fit quadratic regression models and thus confirm that phosphorus deficiency or excess could hinder the growth of A. japonicus as reported in a previous study on tiger shrimp [26].…”

“…During the feeding trial, A. japonicus grew from 9.99 g to 14.67–21.60 g with an acceptable SGR (0.71–1.11%/d), as compared to the growth data from other studies [ 17 , 48 – 50 ]. These positive growth responses fit quadratic regression models and thus confirm that phosphorus deficiency or excess could hinder the growth of A. japonicus as reported in a previous study on tiger shrimp [ 26 ].…”

“…Carrageenan was used to coat sodium dihydrogen phosphate to reduce phosphorus loss in water due to its low solubility loss [ 32 ]. The coated sodium dihydrogen phosphate was prepared using the methods of Li et al [ 17 ] with some modifications: in brief, sodium dihydrogen phosphate was dissolved in distilled water and then equivalent carrageenan was added, following a complete mixing into paste. The mixture was heated in a water bath (95°C) and stirred continuously for 30 min.…”

“…These studies demonstrate that A. japonicus has a low protein (11-17%) and lipid (1.3%) requirement ( [9][10][11]) but high carbohydrate requirement (48.56-49.30%) [12]. In addition, several studies indicated that sea cucumber also required specific vitamins and amino acids for maximizing its growth, including ascorbic acid (100-105.3 mg/kg; [13]), α-tocopherol (23.1-44.0 mg/kg; [14]), riboflavin (9.73-17.9 mg/kg; [15]), lysine (0.58-0.72%; [16]), and methionine (0.76-1.19%; [17]). Up to now, there has been no reports published on phosphorus requirement of A. japonicus.…”

Effects of Three Feed Additives in Low Fish Meal Diet on Growth, Antioxidant Capacity and Intestinal Microbiota of Penaeus monodon

“…Studies have reported that vitamin B 6 can enhance the secretion of digestive enzymes by promoting the growth and development of digestive organs, thereby improving the digestion and absorption capacity [37]. It has been reported that adding vitamin B6 into the diet of Apostichopus japonicus can improve the expression of intestinal amylase [38]. A study by Wei showed that vitamin B 6 can improve the ability of Rhodeus sinensis Gunther to resist hypoxia [39].…”