title: Physiological response, blood chemistry profile and mucus secretion of red sea bream (Pagrus major) fed diets supplemented with Lactobacillus rhamnosus under low salinity stress.
abstract: Environmental stressors caused by inadequate aquaculture management strategies suppress the immune response of fish and make them more susceptible to diseases. Therefore, efforts have been made to relieve stress in fish by using various functional feed additives in the diet, including probiotics. The present work evaluates the effects of Lactobacillus rhamnosus (LR) on physiological stress response, blood chemistry and mucus secretion of red sea bream (Pagrus major) under low salinity stress. Fish were fed four diets supplemented with LR at [0 (LR0), 1 × 102(LR1), 1 × 104(LR2) and 1 × 106(LR3) cells g-1] for 56 days. Before stress, blood cortisol, urea nitrogen (BUN) and total bilirubin (T-BIL) showed no significant difference (P > 0.05), whereas plasma glucose and triglyceride (TG) of fish-fed LR2 and LR3 diets were significantly lower (P < 0.05) than those of the other groups. Plasma total cholesterol (T-CHO) of fish-fed LR3 diet was significantly (P < 0.05) lower than that of the other groups. Furthermore, total plasma protein, mucus myeloperoxidase activity and the amount of mucus secretion were significantly enhanced in LR-supplemented groups when compared with the control group (P < 0.05). After the application of the low salinity stress test, plasma cortisol, glucose, T-CHO and TG contents in all groups showed an increased trend significantly (P < 0.01) compared to the fish before the stress challenge. However, plasma total protein and the amount of secreted mucus showed a decreased trend in all groups. On the other hand, BUN, T-BIL and mucus myeloperoxidase activity showed no significant difference after exposure to the low salinity stress (P > 0.05). In addition, the fish that received LR-supplemented diets showed significantly higher tolerance against low salinity stress than the fish-fed LR-free diet (P < 0.05). The physiological status and the detected immune responses, including total plasma protein and mucus myeloperoxidase activity in red sea bream, will provide a more comprehensive outlook of the effects of probiotics to relieve stress in fish.
authors.affiliation: The United Graduate School of Agriculture Sciences, Kagoshima University, 1-21-24 Korimoto, Kagoshima, 890-0056, Japan. mahmouddawood55@gmail.com.|Laboratory of Aquatic Animal Nutrition, Faculty of Fisheries, Kagoshima University, 4-50-20, Kagoshima, 890-0056, Japan. mahmouddawood55@gmail.com.|Department of Aquaculture, Faculty of Aquatic and Fisheries Sciences, Kafrelsheikh University, Kafrelsheikh, 33516, Egypt. mahmouddawood55@gmail.com.
authors.forename: Mahmoud A O
authors.initials: MA
authors.lastname: Dawood
authors.affiliation: Laboratory of Aquatic Animal Nutrition, Faculty of Fisheries, Kagoshima University, 4-50-20, Kagoshima, 890-0056, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Koshio
authors.affiliation: Laboratory of Aquatic Animal Nutrition, Faculty of Fisheries, Kagoshima University, 4-50-20, Kagoshima, 890-0056, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Ishikawa
authors.affiliation: Department of Nutrition and clinical nutrition, Faculty of Veterinary Medicine, Kafrelsheikh University, Kafrelsheikh, 33516, Egypt.
authors.forename: Mabrouk
authors.initials: M
authors.lastname: El-Sabagh
authors.affiliation: Laboratory of Aquatic Animal Nutrition, Faculty of Fisheries, Kagoshima University, 4-50-20, Kagoshima, 890-0056, Japan.
authors.forename: Saichiro
authors.initials: S
authors.lastname: Yokoyama
authors.affiliation: Laboratory of Aquatic Animal Nutrition, Faculty of Fisheries, Kagoshima University, 4-50-20, Kagoshima, 890-0056, Japan.
authors.forename: Wei-Long
authors.initials: WL
authors.lastname: Wang
authors.affiliation: Laboratory of Aquatic Animal Nutrition, Faculty of Fisheries, Kagoshima University, 4-50-20, Kagoshima, 890-0056, Japan.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Yukun
authors.affiliation: Laboratory of Aquatic Animal Nutrition, Faculty of Fisheries, Kagoshima University, 4-50-20, Kagoshima, 890-0056, Japan.
authors.forename: Adissin
authors.initials: A
authors.lastname: Olivier
mesh_terms: D000818:Animals; D001663:Bilirubin / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D001798:Blood Proteins / Q000378:metabolism; D001806:Blood Urea Nitrogen; D002784:Cholesterol / Q000097:blood; D029941:Fish Proteins / Q000378:metabolism; D006854:Hydrocortisone / Q000097:blood; D052201:Lacticaseibacillus rhamnosus; D009093:Mucus / Q000201:enzymology / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D019936:Probiotics / Q000494:pharmacology*; D054712:Salinity; D021541:Sea Bream / Q000097:blood / Q000378:metabolism*; D013312:Stress, Physiological; D014280:Triglycerides / Q000097:blood
chemical_list: D001786:Blood Glucose; D001798:Blood Proteins; D029941:Fish Proteins; D014280:Triglycerides; D002784:Cholesterol; D009195:Peroxidase; D001663:Bilirubin; D006854:Hydrocortisone
keywords: Lactobacillus rhamnosus; Low salinity stress; Mucus secretion; Myeloperoxidase; Physiological response