Effects of egg size on length, weight, growth and survival of prelarval and early feeding stage of Persian sturgeon (Acipenser persicus)

A study was conducted on the effects of egg size on length, weight, growth and survival of prelarval and early feeding stages of 19 female breeders of Persian sturgeon. The results showed that egg size can affect the total length and weight of prelarvae and there were positive and significant correlation between egg size and total length of prelarvae at the hatching stage and at 2,4,6,8 and 10 days post hatching (P<0.05). There were also positive and significant correlation between egg size and volume of yolk sac at hatching (P<0.05). However, during the first feeding stage the correlation between egg size and survival was very weak

Biological decolorization of xanthene dyes by anaerobic granular biomass

Biodegradation of a xanthene dyes was investigated for the first time using anaerobic granular sludge. On a first screening, biomass was able to decolorize, at different extents, six azo dye solutions: acid orange 7, direct black 19, direct blue 71, mordant yellow 10, reactive red 2 and reactive red 120 and two xanthene dyes—Erythrosine B and Eosin Y. Biomass concentration, type of electron donor, induction of biomass with dye and mediation with activated carbon (AC) were variables studied for Erythrosine B (Ery) as model dye. Maximum color removal efficiency was achieved with 4.71 g VSS L−1, while the process rates were independent of the biomass concentration above 1.89 g VSS L−1. No considerable effects were observed when different substrates were used as electron donors (VFA, glucose or lactose). Addition of Ery in the incubation period of biomass led to a fivefold increase of the decolorization rate. The rate of Ery decolorization almost duplicated in the presence of commercial AC (0.1 g L−1 AC0). Using different modified AC samples (from the treatment of AC0), a threefold higher rate was obtained with the most basic one, \textAC\textH2ACH2, as compared with non-mediated reaction. Higher rates were obtained at pH 6.0. Chemical reduction using Na2S confirmed the recalcitrant nature of this dye. The results attest that decolorization of Ery is essentially due to enzymatic and adsorption phenomena.This work was supported by the PTDC/AMB/69335/2006 project grants (Fundacao para a Ciencia e Technologia, FCT, Portugal), BRAIN project (ID 6681, European Social Found and Romanian Government and the grant of the Romanian National Authority for Scientific Research, CNCS-UEFISCDI, project number PN-II-ID-PCE-2011-3-0559, Contract 265/2011

Effect of dietary soybean meal and multienzyme on intestine histology of beluga sturgeon (Huso huso)

Abstract This study aimed to evaluate the effect of soybean meal and multienzyme supplementation on intestinal histopathology of beluga sturgeon (Huso huso). Nine diets were formulated (40% crude protein, 13% crude fat and 4150 kcal/kg gross energy) in which fish meal was replaced by soybean meal at 0, 40 and 80% supplemented or not with 1 or 2 g/kg of multienzyme Kemin. Fish (initial weight of 820 g) were fed on experimental diets four times daily at 1% body weight for 12 weeks. From histological analyses, intact villus with normal mucosa was found in the FM group, representing the presence of intact epithelium. Supplementation of enzyme at both levels and soybean meal (alone) in the diet resulted in histopathological alterations in the intestine including mild immune cells infiltration, villus blunting, villus fusion, mononuclear immune cells infiltration as well as necrosis. Soybean meal decreased the length of villuses in the proximal and distal intestines (P < 0.05). Enzyme was not able to ameliorate the derangements induced by 80% replacement level of fish meal with soybean meal (treatments SB80E1% and SB80E2%). However, co-administrating of the enzyme at both levels with 40% soybean meal (treatments SB40E1% and SB40E2%) was able to inhibit the soybean meal-induced histopathological impairments