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January 30, 2014
China, USA and Mexico
Recent Research Updates from the Journal Aquaculture
China–Comparing Carotenoid Sources in Shrimp Feeds
From Abstract: Two trials were conducted to determine the effect of carotenoid sources on shrimp (Penaeus monodon), first on growth performance, second on the immune response. In trial one, P. monodon (mean initial wet weight about 2.07 grams) were fed five diets in triplicate:
• Diet 1 = a basal diet without carotenoids
• Diet 2 = 0.1% astaxanthin alone
• Diet 3 = 0.1% astaxanthin and 1% cholesterol
• Diet 4 = 0.25% β-carotene alone
• Diet 5 = 0.25% β-carotene and 1% cholesterol
“In conclusion, all the data suggested that astaxanthin was better than β-carotene either as dietary pigment or as dietary antioxidant in the commercial diet of P. monodon, and the supplement of cholesterol could positively enhance the efficiency of astaxanthin, but not β-carotene.”
Source: Aquaculture. Comparison Effect of Dietary Astaxanthin and Β-Carotene in the Presence and Absence of Cholesterol Supplementation on Growth Performance, Antioxidant Capacity and Gene Expression of Penaeus Monodon Under Normoxia and Hypoxia Condition. Jin Niu (email email@example.com, Key Laboratory of Aquatic Product Processing, Ministry of Agriculture, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Science, Guangzhou 510300, PR China), Hua Wen, Chun-Hou Li, Yong-Jian Liu, Li-Xia Tian, Xu Chena, Zhong Huang and Hei-Zhao Lin. Volumes 422-423, Pages 8-17, February 20, 2014.
United States–Inorganic or Chelated Copper in Shrimp Feeds
From Abstract: Copper is an essential trace element for shrimp and plays important roles in growth, immune function, enzyme function, tissue integrity and as a component of the respiratory pigment hemocyanin. The presence of antagonists in feeds may result in reduced bioavailability and deficiency of copper, which could compromise the growth, and health of shrimp.
This study was conducted to evaluate the response of Pacific white shrimp (Penaeus vannamei) to inorganic or chelated sources of dietary copper. A semi-purified basal diet composed principally of casein, gelatin, soy protein isolate, squid muscle meal and wheat starch was formulated to be deficient in copper (8 parts per million). The diet contained 35% crude protein, and 8% lipid and supplied all other nutritional requirements of the shrimp.
Two sets of diets were formulated from the basal diet, one supplemented with copper from copper sulfate (55, 80, 116, 168, 243 and 363 ppm copper, respectively) and the other with copper from a chelated source of copper (chelated to hydroxy analog of methionine; 26, 39, 52, 65 and 83 ppm copper, respectively). All experimental diets contained 1.2% phytic acid. Groups of juvenile shrimp (N = 8; 0.4 g initial weight) were fed the different diets for a period of 6 weeks. At the end of 6 weeks, the average final weight of shrimp ranged from 8.75 to 10.11 grams and the growth rate ranged from 1.47 to 1.71 grams per week. In general shrimp required 3–4 times more dietary copper from copper sulfate than copper from a chelated copper source to promote comparable growth. Growth rates for treatment groups fed 168 and 243 ppm copper sulfate were significantly higher than the base group. Similarly, growth rates in shrimp fed 52 and 83 ppm copper from the chelated source were also significantly higher than observed for the basal group. Whole body and hepatopancreas copper concentrations varied in relation to dietary copper supplementation. Tissue copper concentrations were significantly lower in shrimp fed the basal diets.
Results from the study suggest that chelated copper is a safe, effective and highly available source of copper for the Pacific white shrimp.
Source: Aquaculture. Comparative Evaluation of an Inorganic and a Commercial Chelated Copper Source in Pacific White Shrimp Litopenaeus Vannamei (Boone) Fed Diets Containing Phytic Acid. Anant S. Bharadwaj (email firstname.lastname@example.org, Novus International Inc., 20 Research Park Drive, St. Charles, Missouri 63304, USA), Susmita Patnaik, Craig L. Browdy and Addison L. Lawrence. Volumes 422-423, Pages 63-68, February 20, 2014.
Mexico–Tolerance of Postlarval to Salinity Variations
From Abstract: The euryhaline white shrimp (Penaeus vannamei) lives in both coastal and oceanic areas through ontogeny. Its osmoregulation pattern and variations in its tolerance to salinity are partially known from several studies under different experimental conditions (developmental stages, salinities and acclimation procedures).
Although P. vannamei is recognized as one of the most euryhaline penaeid species, with adults and juveniles exhibiting a hyper–hypo-osmoregulatory pattern and being able to tolerate a wide salinity range, little is known about larval and early postlarval strategies to cope with salinity fluctuations. In order to establish their euryhalinity range and to fully understand the ontogenetic changes in vannamei’s osmoregulatory pattern, the effect of six salinities (5, 10, 20, 32, 45 and 60 practical salinity unit = psu) on 17 developmental stages were evaluated by directly exposing them to experimental salinities and conducting observations during the next 48 hours. At five hours post-osmotic shock, all developmental stages survived (greater than 20%) in 20, 32 and 45 psu.
The euryhalinity and osmoregulation pattern changed at some developmental stages of vannamei. The hyper–hypo osmoregulatory pattern exhibited by juvenile and adult appears to be established early in the first postlarval stage PL-1 (ontogenetic osmoregulation pattern type 3), with higher tolerance to salinity variations observed in PL-2, PL4 and PL-22 suggesting that vannamei shows a progressive increase in the efficiency of osmoregulatory mechanism following the last metamorphosis.
Source: Aquaculture. Osmoregulation Pattern and Salinity Tolerance of the White Shrimp Litopenaeus Vannamei (Boone, 1931) During Post-Embryonic Development. Osmoregulation Pattern and Salinity Tolerance of the White Shrimp Litopenaeus Vannamei (Boone, 1931) During Post-Embryonic Development. Jennyfers Chong-Robles (email email@example.com, Universidad Autónoma del Estado de Baja California, Laboratorio de Ecología Molecular, Kilómetro 103 Carretera Tijuana-Ensenada, Ensenada, Baja California, Mexico), Guy Charmantier, Viviane Boulo, Joel Lizárraga-Valdéz, Luis M. Enríquez-Paredes and Ivone Giffard-Mena. Volumes 422-423, Pages 261-267, February 20, 2014.
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