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A 2× 3 factorial design was used to reevaluate the dietary protein requirements and to determine the optimum dietary protein to energy (P/E) ratios in Japanese eel, Anguilla japonica, reared in the recirculating system. For each of two experiments, six experimental ...

... 6 Centro de Estudos do Ambiente e do Mar (CESAM)/Departamento de Biologia da Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal. *Correspondence: Ike Olivotto,. *Correspondence: Corresponding author. Publication History. ...

In this study baker's yeast was evaluated as a substitute for live Dunuliella tertiolecta algae in the culture of the brine shrimp Artemia. Consumption of fresh baker's yeast resulted in poor growth and survival of brine shrimp. However, the nutritional value of the yeast sigaificantly improved after complete removal of the yeast cell wall by enzymatic treatment. Baker's yeast was also made digestible for Artemia by simple chemical treatment which did not reduce rigidity of the yeast cell. The external mannoprotein layer of the yeast cell wall is probably the major barrier to digestion by Artemia. Chemically treated baker's yeast offers promising possibilities as a substitute for algal feeds in aquaculture.

Tilapia–shrimp polyculture has played an important role in current efforts to control luminous bacterial disease caused by Vibrio harveyi. At present, green water technology is most extensively used by shrimp farmers in Negros Island in the central Philippines. While the contribution of tilapia as a biomanipulator is highlighted in the literature, the mechanism of action is not well understood. Data were gathered from shrimp ponds practicing two production systems: (a) green water system (probiotics + tilapia) and (b) closed/semiclosed system (probiotics alone). There was no difference between luminous Vibrio count (P < 0.05) in both systems, and water quality was found to be similar (P < 0.05). Because the green water system uses a bigger reservoir to raise the tilapia biomass, the net shrimp production was lower. In terms of direct cost of production, however, the green water system was 10–15% lower than the closed/semiclosed system because of significantly less aeration required. The polyculture maintained a more stable plankton environment during the early months of culture, which increased survival of shrimps. Various pathways are presented for the control of luminous bacterial growth in polyculture ponds: (a) fish feeding on organic wastes and conversion to feces; (b) selective fish foraging to increase the dominance of beneficial phytoplankton; (c) bioturbation of pond sediments; and (d) release in the water column of antimicrobials, fungi, or competing bacteria from the skin and gut mucus of tilapia.

In the rearing of larval marine fish, any diet that reduces dependance on live prey production is of technical and economic interest. Weaning juveniles with a completely developed digestive tract to a conventional diet, (i.e., “late weaning”) can be successful in any marine fish species. For example, weaning one-month-old sea bass (20 mg) to the study's reference diet, Sevbar, resulted in over 85% survival (40% from hatching) and 1.25 g fish at day 90 (at 19 C)In contrast, “early weaning” of larvae to special microdiets during the first month is still difficult. The best way to reduce live prey utilization in sea bass is to wean larvae at about 3–4 mg in size (day 20). If weaning could be accomplished 15 days earlier, Artemia savings could be as high as 80%. However, this introduces risks relative to growth retardation (30% weight loss) and lower juvenile quality, including greater size variability and skeletal abnormalities. Similar results have been obtained with commercial microparticles (Fry Feed Kyowa) and experimental microbound diets (MBD) made from raw materials (alginate MBD) or preferably from freeze-dried protein sources (zein MBD).Total replacement of live prey is still impossible in marine fish. Sea bass larvae fed formulated diets exclusively from first feeding (0.3 mg larval wet weight), or even from their second week of life onwards, exhibited low survival and poor growth. Better results can be obtained when formulated diets are used in combination with live prey from first feeding, although the optimal ratio of live prey to formulated diet is still to be specified.

It is well known that soft iron owes its transformation into steel to the addition of carbon. Carbon is the hardest substance on Earth - diamond. Carbon is the mainstay of Life on Earth, since everything living on our planet is built from it. This all means: carbon is the mainstay of our world. But find out: it is also the stronghold of the entire Universe! The mythical metal orichalcum spoken of by Plato and Tolkien's mithril are carbon, structurally superior to diamond. The Moon is made from it by the hand of God. The UFO is made from it by the hand of the Other. // Общеизвестно, что своим превращением в сталь мягкое железо обязано добавке углерода. Углеродом есть самое твердое вещество Земли — алмаз. Углерод — оплот Жизни на Земле, ибо из него на ней построено живое. Все это означает: углерод в нашем мире есть главная твердь. Но узнайте: он есть и твердь Мира! Мифичный металл орихалк, о каком рек Платон, и мифрил Толкина — это углерод, структурно высший над алмазом. Из него рукою Бога сделана Луна. Из него рукой Иного сделан НЛО.

Carangid fishes of the genus Trachinotus have received much attention as mariculture candidates. Foremost among these is the Florida pompano (T. carolinus), which drew considerable research attention in Florida and Alabama that culminated in several business-sponsored, intensive but uneconomical attempts to commercially culture pompano in south Florida and the Dominican Republic from the 1960's through the mid-1970's. These attempts, however, demonstrated the biological feasibility of rearing pompano. Recently renewed interest has developed in commercially culturing pompano and two related species, Atlantic permit (T. falcatus) and palometa (T. goodei). Research on Trachinotus spp. in Martinique, Venezuela and Miami, Florida, is summarized, together with problems and prospects for commercial culture of these species.

An 8-wk feeding trial was conducted with a 3 ± 4 factorial design for evaluating the nutritional relationship between phospholipids (lecithin at 0, 1.5% or 3% of diet) and choline chloride (0, 1,000, 2,000, or 4,000 mg/kg diet) in juvenile Litopenaeus vannamei. In addition, diets with five graded levels of choline chloride (0, 500, 1,000, 2,000, and 4,000 mg/kg) without supplemental phospholipids or cholesterol were fed for determining the dietary choline requirement. Overall survival was 99% with no difference among the dietary treatments. The choline requirement was estimated to be 871 mg/kg diet without dietary phospholipids. No choline requirement was evident when lecithin was provided at 1.5% and 3% of diet. Shrimp growth significantly increased with incremental dietary phospholipids regardless of choline chloride level. These results indicate that lecithin could effectively provide choline. Conversely, synthesis of phospholipids from choline could not meet the phospholipids requirement of shrimp. Both dietary lecithin and choline chloride supplementation reduced lipid in shrimp muscle. However, only lecithin supplementation increased lipid in hepatopancreas, and dietary choline chloride decreased the level of other phospholipids (except phosphatidylcholine) in shrimp muscle.