Experiment on larval rearing of Penaeus monodon fed with cultured diatom Chaetoceros calcitran and fermented vegetable trash

A brief account is given of experiments undertaken rearing Penaeus monodon larvae fed on diatom (Chaetoceros calcitran) and fermented vegetable trash, which included fruits and their peels, vegetables and rice. The possible use of high protein content trash materials as a feed substitute is examined briefly.

Texturised meat from low cost fish

A comparative study of the suitability of five species of fish, namely, threadfin bream (Nemipterous [sic] japonicus), cat fish (Tachysurus fella), ribbon fish (Trichiurus spp.), barracuda (Sphyraena jello) and jew fish (Pseudosciaena spp.) for the production of texturised meat has indicated that all these species are good source for the purpose. Protein content of the final product from all the species was higher than that prescribed for FPC type A. The product had excellent rehydration capacity and firm and elastic texture. No significant difference was observed in the rehydration capacity of the texturised meat from all the species studied. Salt concentration was found to influence the texture and salt content of 1.5 to 2% was found to result in the desirable firm and elastic texture. Rehydration capacity was not influenced to any significant extent by the salt content.

Nutritional evaluation of texturised meat from Nemipterus japonicus

Evaluation of the nutritional quality of texturised fish meat from threadfin bream (Nemipterus japonicus) is reported. Proximate composition and amino acid analysis showed that its protein content is very high with all the essential amino acids present in higher levels than those prescribed for man in the 1973 FAO/WHO amino acid scoring pattern. Lysine amounted to 11.0 g per 16 g N of which 75 percent is biologically available. Studies on PER and NPU also corroborate the excellent nutritional quality of the texturised meat.

Studies on two unexploited fish species: Peristedion adeni and Peristedion weberi

The chemical composition and nutritional quality of Peristedion adeni and Peristedion weberi, two unexploited fish species available in abundance in the Exclusive Economic Zone of India are reported. Size of the fish is small and separation of edible meat is difficult. Best method of utilization of the fish is conversion into meal. Meals having crude protein content varying from 55.0 to 57.0%, ash content from 17.0 to 19.6% and fat content from 17.7 to 18.1% can be prepared from the two species of fish. PER values of the meals are lower than that of casein. Amino acid analysis showed that isoleucine, leucine and valine are not present in the meals in adequate quantities compared to the FAO/WHO (1973) prescribed pattern.

Identification and determination of muscle's fatty acids and amino acids in Cobia and Indian squid

The present study aims to find the effect of freezing Time on the quality of Cobia (Rastrelliger kanagurta) and Indian Squid in commercial scale during freezing and subsequent frozen storage (−18◦C). Total time for freezing was significantly different (P<0.05) between the Cobia and Indian squid samples. The difference in the freezing time could be attributed to the varied quality of the 2 samples. Upon freezing, the moisture content decreased in Indian Squide samples compared to Cobia freezer where protein content decreased in both the samples. Upon freezing and during frozen storage, lipid oxidation products (peroxide value, and free fatty acid value) and volatile bases (total volatile base nitrogen) showed an increasing trend in both the samples with values slightly higher in Indian squid samples compared to cobia frozen samples. The total plate counts showed a significantly (P<0.05) decreasing trend in both the samples. K value did not show any significant (P<0.05) difference between the samples whereas the histamine formation was significantly (P<0.05) increased in Indian squid frozen samples compared to cobia samples. The taste and overall acceptability was significantly different (P<0.05) in cobia samples compared to Indian squid frozen samples on 5th month. Both samples were in acceptable condition up to 5 month but the Cobia frozen samples quality was slightly better than the air blast frozen samples.

Diet and feeding behavior of Rhinopithecus bieti at Xiaochangdu, Tibet: Adaptations to a marginal environment

The diet and feeding ecology of a wild subpopulation of black-and-white snub-nosed monkeys (Rhinopithecus bieti) were studied at Xiaochangdu in Honglaxueshan Nature Reserve, Tibet. This region is climatologically harsher than any other inhabited by non-human primates. Black-and-white snub-nosed monkeys fed on 48 parts of 25 plant species, at least three species of lichens and seven species of invertebrates. The number of food items exploited varied markedly among seasons, with dietary diversity being greatest in spring and summer. In winter, black-and-white snub-nosed monkeys had to subsist on fallback foods such as dried grass and bark. Ubiquitous lichens formed a major dietary constituent throughout the year, contributing about 75% of feeding records. Even though lichens act as a staple, our findings signify that the monkeys at Xiaochangdu prefer feeding on foliage, which is higher in protein content than the former. We provide evidence that black-and-white snub-nosed monkeys are able to cope with an array of food items other than lichens and hence can be regarded as feeding generalists. We discuss the results with reference to previous studies on other subpopulations living in habitats that are floristically more diverse and offer more plant food items than the marginal habitat at Xiaochangdu.

Effects of sediment anoxia and light on turion germination and early growth of Potamogeton crispus

Potamogeton crispus is a cosmopolitan aquatic species and is widely used as a pioneer species for vegetation restoration of eutrophic lakes. However, many restoration projects applying P. crispus turions have not been successful. Earlier studies focused on effects of light and temperature on turion germination. The purpose of this study was to determine whether sediment anoxia and light interactively affected the turion germination and early growth of P. crispus. Anoxic conditions in the experiment were produced by adding sucrose to the sediment. The germination rate of the turions was 68-73% lower in the highly anoxic condition treatment than in the control. Medium light intensity (10% of natural light at the water surface) was more favorable for germination under slightly anoxic conditions than either low or high light intensity. The growth of newly-formed sprouts was also significantly inhibited by sediment anoxia. Photosynthesis and shoot biomass were reduced under sediment anoxia, whereas total chlorophyll content, root biomass, and soluble protein content were highest in the low anoxic condition treatment. Medium light improved net photosynthesis and biomass production of the sprouts. We conclude that turion germination and sprout growth can be significantly inhibited by sediment anoxia. Medium light intensity may alleviate this inhibition by anoxia, but light has little effect when sediment anoxia is severe. For the purposes of vegetation restoration, more attention should be paid to the role of sediment anoxia, and it is necessary to improve sediment and light conditions for turion germination and early growth of P. crispus in eutrophic lakes. These results will contribute to a more complete understanding of turion germination dynamics of P. crispus and will be useful for future restoration programs.

Mouse Toxicity of Anabaena flos-aquae from Lake Dianchi, China

Some species of the genera Anabaena can produce various kinds of cyanotoxins, which may pose risks to environment and human health. Anabaena has frequently been observed in eutrophic freshwater of China in recent years, but its toxicity has been reported only in a few studies. In the present study, the toxicity of an Anabaena flos-aquae strain isolated from Lake Dianchi was investigated. Acute toxicity testing was performed by mouse bioassay using crude extracts from the lyophilized cultures. The mice exposed to crude extracts showed visible symptoms of toxicity and died within 10-24 h of the injection. Serum biochemical parameters were evaluated by the use of commercial diagnostic kits. Significant alterations were found in the serum biochemical parameters: alkaline phosphatase (AKP), gamma-glutamyl transpepticlase (gamma-GT), aspartate amino transferase (AST), alanine amino transferase (ALT), AST/ALT ratio, total protein content, albumin content, albumin/globulin (A/G) ratio, blood urea nitrogen (BUN), serum creatinine (Ssr), and total antioxidative capacity (T-AOC). Histopathological observations were carried out with hematoxylin and eosin (HE) stain under light microscope. Severe lesions were seen in the livers, kidneys, and lungs of the mice injected with crude extracts. The alterations of biochemical parameters were in a dose-dependent manner, and the severities of histological lesions were in the same manner. Based on biochemical and histological studies, this research firstly shows the presence of toxin-producing Anabaena species in Lake Dianchi and the toxic effects of its crude extracts on mammals. (C) 2008 Wiley Periodicals, Inc. Environ Toxicol 24: 10-18, 2009.

Effect of inclusion of blue-green algae meal on growth and accumulation of microcystins in gibel carp (Carassius auratus gibelio)

Six isonitrogenous (crude protein content: 38%) and isoenergetic (gross energy content: 17 kJ g(-1)) diets were formulated to investigate the effects of inclusion of blue-green algae meal on gibel carp (Carassius auratus gibelio). In each diet, 15% of the protein was supplied by fishmeal; the remainder was supplied by soybean meal and blue-green algae meal. Diet 1 was used as control with no blue-green algae meal whereas the content in diets 2-6 was 15.15, 29.79, 44.69, 59.58 and 74.48%, respectively. Each diet was fed to five groups of gibel carp for 12 weeks in a flow-through system. Final body weight and specific growth rate (SGR) of fish fed diet 5 were significantly lower than the control diet (P < 0.05). Mortality of gibel carp increased with increase in algae meal inclusion (P < 0.05), but there was no significant difference between fish fed diets 3-6 (P > 0.05). Feed conversion efficiency (FCE) decreased with the increase in algae meal inclusion (P < 0.05). Fish-fed diet 6 showed the highest feeding rate (P < 0.05), while there were no significant differences among the other groups (P > 0.05). Apparent digestibility coefficient of dry matter, protein, and energy decreased with increasing algae meal inclusion in the diets (P < 0.05). Aspartate aminotransferase (GOT) activity in the liver was not significantly different among groups (P > 0.05). Liver alanine aminotransferase (GPT) activity of fish-fed diets 4, 5 and 6 was significantly lower than the control diet (diet 1; P < 0.05). Microcystins in the muscle, liver, gallbladder, and spleen increased with increasing algae inclusion (P < 0.05).

Effect of replacement of fish meal by meat and bone meal and poultry by-product meal in diets on the growth and immune response of Macrobrachium nipponense

The potential use of poultry by-product meal (PBM) and meat and bone meal (MBM) as alternative dietary protein sources for juvenile Macrobrachium nipponense was studied by a 70-day growth trial. Triplicate groups of M. nipponense (initial body weight: 0.37 g) were fed at 20.7-22.4 degreesC on each of the five isoenergetic and isonitrogenous diets (protein content about 38%) with different replacement of fish meal by MBM or PBM. The control diet used white fish meal as the sole protein source, the other four diets were prepared with 15% or 50% fish meal protein substituted by either MBM (MBM15, MBM50) or PBM (PBM15, PBM50). The results showed that replacement of fish meal by MBM in diets did not affect growth performance of M. nipponense (P > 0.05), while specific growth rate in PBM15 was significantly higher than that in other groups (P < 0.05). Survival rates of shrimp fed with MBM15 diet were significantly higher than that in other groups (P < 0.05). No significant differences in immunological parameters, including total haemocyte count (THC), phenoloxidase activity (PO) and respiratory burst (O-2(-)), were observed between the shrimps that were fed five experimental diets, and all determined immunological parameters in control groups were slightly higher than those in replacement groups. In conclusion, either MBM or PBM investigated could replace up to 50% fish meal protein in diets for M. nipponense. (C) 2003 Elsevier Ltd. All rights reserved.

Effect of ration on the growth and energy budget of Chinese longsnout catfish, Leiocassis longirostris Gunther

The effect of ration on growth and energy budget of Chinese longsnout catfish was investigated in a growth trial. Fish of initial body weight of 6.5 g were fed at six ration levels (RLs): starvation, 0.8%, 1.6%, 2.4%, 3.2% of body weight per day, and apparent satiation for 8 weeks. Fish were weighed biweekly to adjust feed amount. The results showed that specific growth rate in wet weight, protein and energy increased logarithmically with increased RLs. The relationship of specific growth rate in wet weight (SGRw, % day(-1)) and RL (%) was a decelerating curve: SGRw=-0.62+3.10 Ln(RL+1). The energy budget equation at satiation was: 100 IE=12.94 FE+5.50(ZE+UE)+40.07 HE+41.49 RE, where IE, FE, (ZE+UE), HE, RE are food energy, faecal energy, excretory energy, heat production and recovered energy respectively. Body composition was slightly but significantly affected by ration size except for protein content. The most efficient ration based on the relationship between RL and feed efficiency ratio in energy (FERe) was 1.8% of body weight per day.

Acute biochemical responses of a submersed macrophyte, Potamogeton crispus L., to high ammonium in an aquarium experiment

Acute biochemical responses of Potamogeton crispus L. to high external ammonium were investigated in an aquarium experiment. Shoots of P. crispus were incubated in aquaria for 24 h or 48 h at five treatments of ammonium-0, 1, 5, 10 and 20 mg/L NH4-N. Soluble sugar content of the shoots declined markedly with increasing ammonium levels, whereas soluble amino acid content increased dramatically. Responses of two antioxidant enzymes as well as soluble protein content fit a lognormal distribution with increasing ammonium levels. High ammonium levels (NH4-N greater than or equal to 5 mg/L) caused significant acute biochemical changes in P. crispus, which potentially could lead to significant biochemical damage.

Optimization of growth and fatty acid composition of a unicellular marine picoplankton, Nannochloropsis sp., with enriched carbon sources

A unicellular marine picoplankton, Nannochloropsis sp., was grown under CO2-enriched photoautotrophic or/and acetate-added mixotrophic conditions. Photoautotrophic conditions with enriched CO2 of 2800 mul CO2 l(-1) and aeration gave the highest biomass yield (634 mg dry wt l(-1)), the highest total lipid content (9% of dry wt), total fatty acids (64 mg g(-1) dry wt), polyunsaturated fatty acids (35% total fatty acids) and eicosapentaenoic acid (EPA, 20:5omega3) (16 mg g(-1) dry wt or 25% of total fatty acids). Mixotrophic cultures gave a greater protein content but less carbohydrates. Adding sodium acetate (2 mM) decreased the amounts of the total fatty acids and EPA. Elevation of CO2 in photoautotrophic culture thus enhances growth and raises the production of EPA in Nannochloropsis sp.

Utilization of several plant proteins by gibel carp (Carassius auratus gibelio)

Six isonitrogenous (gross protein content 35%) and isoenergetic (gross energy content 17 kJ g(-1)) diets were formulated to investigate the effects of inclusion of plant proteins on the gibel carp (Carassius auratus gibelio L.). The plant proteins tested were: soybean cake (SBC), potato protein concentrate (PPC), peanut cake (PNC), cottonseed cake (CSC) and rapeseed cake (RSC). Fish meal (FM) was used as control. In each diet, 27% of the protein was supplied by fish meal, and the rest supplied by the plant protein tested. Each diet was fed to three groups of gibel carp for 8 weeks in a recirculation system. Specific growth rate (SGR) in fish fed the control diet was significantly higher than those in the other groups, and SGR in fish fed the PPC was significantly lower than in fish fed other plant proteins. There was no significant difference in SGR among the other groups. Feeding rates were ranked in the order: RSC > CSC > FM > PNC > SBC > PPC. Conversion efficiency was highest in groups fed FM, SBC and PNC, followed by groups fed CSC and RSC, and was lowest in the group fed PPC. The fish fed PPC showed lower protein retention than those fed FM and SBC. FM showed highest energy retention while PPC showed lowest, There was no significant relationship between SGR and intake of digestible protein (g g(-1) day(-1)), digestible lysine (g g(-1) day(-1)), digestible methionine (g g(-1) day(-1)) or digestible total essential amino acids (g g(-1) day(-1)), suggesting that the differences in SGR could not alone account for any of these variables.

Growth of Chlorella vulgaris in cultures with low concentration dimethoate as source of phosphorus

The growth response of Chlorella vulgaris to low concentration of dimethoate, an organophosphorus pesticide, was studied. Results show that cell density, protein content, chlorophyll pigment and alkaline phosphatase activity were all increased, which indicates that low concentration dimethoate can accelerate growth of Chlorella vulgaris. (C) 1997 Elsevier Science Ltd.