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  • 1
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: We report the results of controlled feeding trials on the tiger shrimp, Penaeus monodon (Fabricius). The desired colour was obtained by feeding a diet supplemented with astaxanthin (50 p.p.m) for 7–8 weeks before harvest. Similar coloration was achieved, however, by including in the feed an algal material (Dunaliella salina) that contains β-carotene but no astaxanthin. Feed containing β-carotene at 125 p.p.m also gave the required coloration at 7–8 weeks, whereas the same results was obtained after only 5–6 weeks when feed containing 175 p.p.m β-carotene was used. Irrespective of whether the shrimp were fed astaxanthin or β-carotene, the main carotenoid accumulation was astaxanthin, in free and esterified form, showing that P. monodon has the metabolic ability to convert β-carotene into astaxanthin. The supplementation with β-carotene or astaxanthin had no significant effect on growth, average final weight, survival rate or feed conversion ratio, nor on the immune response of the shrimp in terms of production of haemocytes phenoloxidase in the cytoplasmic granules of the haemocytes, microbial clearance ability and resistance to infectious diseases. This is a highly significant development for commercial aquaculture, because it shows that supplementing diets with β-carotene can achieve the same result as doing so with much more expensive astaxanthin.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 38 (1991), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Sphaerospora epinepheli n. sp. is described from grouper, Epinephelus malabaricus, in cage-cultured and wild fish collected from both coastal lines of southern Thailand. Subspherical to spherical spores and mono- or disporous pseudoplasmodia were observed in the lumen of kidney tubules. Pseudoplasmodia were round to elongate, size range 15.6–22.9 μm (length) × 8.4–21.6 μm (width). Spores were 7.8–10.0 μm (length) × 12.3–14.5 μm (thickness), and 7.0–9.5 μm (width) with two spherical polar capsules of equal size measuring 2.9–4.4 μm in diameter and containing polar filaments with six or seven windings. Two uninucleate sporoplasms showed iodine vacuoles. Blood stages, similar to C-blood protozoans observed from freshwater fish in Europe, were found from peripheral blood smears of grouper. Ultrastructural studies of blood stages showed a similar structure to unidentified mobile protozoans from the blood of carp. Electron dense bodies were observed in the cytoplasm of the primary cell blood stages. Infected proximal-tubular epithelial cells showed highly vacuolated cytoplasm and pycnotic nuclei.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1365-2761
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Aflatoxin B1 was studied in juvenile black tiger shrimp (Penaeus monodon Fabricius) (1–2 g) to see the effects on growth performance and histopathology, and in adult shrimp (10–12 g) to study the effects on immuno-physiological function, histopathology and aflatoxin residue. Feeds supplemented with 0, 50, 100, 500, 1000 and 2500 p.p.b. aflatoxin B1 were given to test groups for an 8-week period. Aflatoxin B1 in the diet showed highly negative correlation to average weight, weight gain and survival (r = − 0.99, −0.96 and −0.95 at P 〈 0.05, respectively). Aflatoxin B1 at 50–100 p.p.b. produced no effect on growth in juvenile shrimps; however, growth was reduced when aflatoxin B1 concentrations were elevated to 500–2500 p.p.b. Survival dropped to 26.32% when 2500 p.p.b. aflatoxin B1 was given, whereas concentrations of 50–1000 p.p.b. had no effect on survival.Total haemocyte count and phenoloxidase activity increased by the fourth week in shrimp receiving the highest concentration of aflatoxin B1 and gradually declined from the sixth to eighth week. Alkaline phosphatase and cholesterol in serum have no correlation to aflatoxin in the diet after 4 weeks of the feeding but have a high correlation after 6 weeks of feeding. Calcium and phosphorus levels in the blood have no correlation with the aflatoxin concentration in diet.There were marked histological changes in the hepatopancreas of shrimp fed diet containing aflatoxin B1 at a concentration of 100–2500 p.p.b. for 8 weeks, as noted by atrophic changes, followed by necrosis of the tubular epithelial cells. Severe degeneration of hepatopancreatic tubules was common in shrimp fed high concentrations of aflatoxin B1. Infiltration of connective tissue into interstitial tissue of the hepatopancreas, as well as encapsulation of necrotic tissue/cells, was also observed. The residue detected in muscle was higher than in the head and shell after 4 weeks of feeding. After 6 weeks, the residue found in muscle was very low and the residue found in the mixture of head and shell decreased compared to the 4-week sample.
    Type of Medium: Electronic Resource
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