Resistance to pathogen Agent Species Route of exposure Length of administration Mechanism of action/results References Aeromonas hydrophila Yeast glucan Tilapia and grass carp i.p 14 days ↑ protection in both species and number of NTB-positive staining cells [219]   Glucan Rohu Oral 7 days ↑ phagocytotic activity, bactericidal activity, antibody titre and agglutinin level [220]   Glucan Rohu i.p 28 days ↑ phagocytotic activity, lysozyme activity, bactericidal activity, complement activity and resistance [221]   Garlic Rohi i.p 10 days ↑superoxide production, lysozyme activity and resistance [222]   Glucan Catla i.p 30 days ↑ antibody titre and macrophage activating factor [223]   Glucan from S. cerevisiae Carp (25-30 g) i.p (0, 100, 500 and 1000 µg fish-1) 14 days ↑ total leukocyte count and neutrophil and monocytes, increase survival in a challenge experiment with Aeromonas hydrophila [224]   Glucan from S. cerevisiae Carp (25-30 g) i.p (0, 100, 500 and 1000 µg fish-1) 14 days ↑ total leukocyte count and neutrophil and monocytes, superoxide anion production by kidney macrophages and resistance (500 µg) against A. hydrophila [225]   β-glucan in combination with LPS Carp (25-30 g) i.p, bathing and oral ad-ministration 14 ↑ total blood leukocyte count and neutrophil and monocytes and resistance against A. hydrophila when i.p and oral administration were used [226]   Levamisole carp Diet (0, 125, 250 and 500 mg kg-1) 70 days ↑ resistance and erythrocyte count, haemoglobin content, haematocrit, total serum protein, albumin and globulin of fish fed 250 mg kg-1 [227]   β-glucan and S. uvarum Carp i.p 15 days ↑ resistance and serum lysozyme activity [228]   Glucan Asian catfish Oral 30 days ↑ antibody titre and protection [229]   Glucan Blue gourami i.p (5, 10, 20 and 40 mg kg-1) 22 days ↑ chemiluminescent response of head-kidney phagocytic cell isolated from fish i.p with a dose of 20 mg kg-1 and resistance [230]   Glucan Indian major carp i.p 1 week ↑superoxide production and phagocytic activity resistance unclear [231]   S. cerevisiae zebrafish i.p (0.5, 2 and 5 mg ml-1) 6 + 4 days ↑ resistance (5 mg), myelomonocytic cells in kidney and enhanced the ability of kidney cells to kill the pathogen [232]   S. cerevisiae Nile tilapia Oral (0, 0.25, 0.5, 1, 2 and 5 g kg-1) and i.p 12 weeks + 10 days 12 weeks ↑ growth, feed utiliza-tion and protein turn-over (1-5 g kg-1) and resistance (5 g kg-1) [233]   S. cerevisiae Nile tilapia Oral (2 % autolyzed yeast; 0.3 % cell wall) 70 days ↑thrombocytes and nonspecific acute inflammatory response ↓neutrophils, macro-phages an lymphocytes [234]   Green tea (Camellia sinensis) Nile tilapia Oral (0, 0.125, 0.25, 0.5, 1 and 2 g kg-1) 12 weeks + 10 days (i.p challenge) ↑ growth and feed utilization (highest at 0.5 G kg-1), haematological and biochemical parameters (0.25-2 g kg-1) and resistance with increasing inclusion levels [235]   Debaryomyces hansenii Leopard grouper Oral (106 yeast g-1) 5 weeks ↑ resistance and growth → immunological para-meters after 4 weeks [236]   Macrogard Tench Oral (0, 0.5, 1 and 2 g    kg-1) 1 month ↑ resistance and phagocytic activity (1 and 2 g kg-1) [237]   Schizophyllan Two orna- mental fish species i.p (108 cells ml-1) 24 days ↑ resistance against both pathogens [238] A.hydrophila and Pseudomonas fluorescens Glucan Brook trout i.p and 30 min immersion 4 weeks ↑ resistance (up to 7  days). By day 14 no resistance was reduced [239] Aeromonas salmonicida Macrogard Trout Oral 1 week ↑ MPO activity, phagocytic activity, superoxide production and Ig level [240] Aeromonas salmonicida and Vibrio salmonicida Laminaran Atlantic salmon i.p (23.6 mg kg-1) 35 days ↑resistance against V. salmonicida → resistance against A. salmonicida [241] Aphanomyces invadans Ergosan Striped snakehead Injected intramuscularly 2 weeks ↑ inhibitory effect of  Serum and macrophage activating factor [57] Edwardsiella ictaluri Yeast glucan Channel catfish i.p  2 weeks ↑ resistance and phagocytic activity [153]   Glucan Channel catfish Oral 2 weeks ↑ macrophage and  neutrophil migration → resistance   [242] Edwardsiella tarda Glucan Carp i.p 12 days ↑ resistance [152]   Glucan Rohu i.p 10 days ↑ bactericidal activity  ↑resistance   [243]   Glucan Rohu i.p 28 days ↑ phagocytotic activity, lysozyme activity, bactericidal activity, complement activity and resistance [221]   Glucan - injections Rohu i.p 28 days ↑ phagocytotic activity, lysozyme activity, bactericidal activity, complement activity and resistance [222]   Yeast glucan Tilapia and grass carp i.p 14 days ↑ protection in both species and number of NTB-positive staining cells [219] Pasteurella piscicida Glucan Yellowtail i.p 10 days → resistance [244] Photobacterium damselae ssp. piscicida Glucan Gilthead sea bream Immersion (107 cells l-1) 10 days ↑ resistance (10 g kg-1) → resistance (5 g kg-1) and phagocytic activity [245] Vibrio alginolyticus Glucan White shrimp Oral 120 hours ↑ resistance, phenol- oxidase and respiratory burst [246]   Glucan Fresh-water prawn Bath exposure with glucan. 4 hours + 1 week immersion with the pathogen ↑ haemocyte lysate supernatant, lysozyme and phosphatase active-ties and increased resistance → total protein content [247] Vibrio anguillarum Yeast glucan Salmon i.p 20 days ↑ resistance [183]   High-M alginate Turbot Immersion (105 cells ml-1) 1 week ↑ resistance [53]   High-M alginate Atlantic halibut Immersion (5x105 or 1.4x107 cells ml-1) Different periods during initial feeding ↑ resistance at the highest dose → resistance at lowest dose [215]   Cationic cod milt protein Atlantic cod (5 g) Bath challenge (5x106 cells ml-1) 4 weeks ↑ resistance [248] Vibrio anguill-arum and Vibrio campbellii Glucan from S. cerevisiae Gnoto-biotic Artemia Immersion (5x106 cells ml-1) 6 days ↑ resistance against both pathogens [249] Vibrio campbellii Glucan from S. cerevisiae Artemia Immersion (5x106cells ml-1) 5 days Protection against Vibrio campbellii when supplied in advance of the challenge [250]   Glucan from S. cerevisiae Artemia Immersion (5x106 cells ml-1) 6 days ↑ survival and resistance against V. campbellii [251] Vibrio damsela Yeast glucan Turbot Yeast glucan was used as adjuvant 42 days ↑ activities of the immune parameters when glucan was injected after the bacterin [252] Vibrio harvei Glucan Croaker i.p 8 weeks ↑ lysozyme activity, phagocytic activity and resistance (0.09%) → resistance (0.18%) [253] Vibrio vulnificus Glucan Tiger shrimp Immerse 43 days ↑ resistance in shrimp treated with 0.5 and 1 mg/ ml glucan but no in groups treated with 0.25 and 2 mg/ ml glucan [194] Vibrio sp. 90-69B3 Yeast Culture Pacific white shrimp Oral i.p after 4 weeks ↑ resistance [254] Yersinia ruckeri Yeast glucan Salmon i.p 20 days ↑ resistance [183]   S. cerevisiae Rainbow trout i.p 14 days ↑ resistance, growth, lysozyme and comple-ment activities [255] Lactococcus garviae Alginate micro- particles Trout i.p 3 weeks → resistance [256] Streptococcus sp. Glucan Yellowtail i.p 10 days ↑ resistance and serum complement ↑ lysozyme activity [244]   Sodium alginate Grouper i.p 6 days ↑ lysozyme activity, respiratory bursts, phagocytic activity and resistance [257] Streptococcus iniae Glucan Hybrid striped bass Oral 3 weeks → resistance [258]   Glucan Nile tilapia Oral 14 weeks ↑ resistance when fish were fed 100 and 200 mg glucan [259]   Glucan Shark Oral 2 weeks ↑ resistance [260] Virus             IHNV Glucan Rainbow trout i.p 18 days ↑ resistance → respiratory bursts and TNF-α-expression [39] WSSV β-1,3-glucan Penaeus monodon Oral (0 and 2g kg-1) 15 days ↑ resistance [261]   β-1,3-glucan Penaeus monodon i.p 20 days ↑ resistance and the Immune system [262]   Marine yeast (Candida sake) White prawn Oral (10 %) 40 + 10 days ↑ immunity index and resistance [263]   Marine yeast glucan Penaeus monodon Oral 21 days ↑ resistance, but higher molecular weight and lower degree of branching acts better [264] Parasite             Loma morhua Glucan Atlantic cod Oral n.i ↑ lymphocyte density [265] Loma salmonae β-1,3/1,6 glucan Rainbow trout i.p (0, 50, 100, 500 and 1000 µg) 10 weeks During week 8-9 post exposure a significant reduction in no. of xenoma-positive fish was noticed. [266] Symbols represent an increase (↑) in the specified response; no change (→); decrease (↓); n.i – no information given. i.p – intraperitoneal injection n.i – no information given IHNV – infectious hematopoietic necrosis virus IHNV – infectious hematopoietic necrosis virus WSSV - White spot syndrome virus

Table 3: Immunostimulants and disease susceptibility in fish and shrimps.