Effects of silver carp and the small indigenous fish mola Amblypharyngodon mola and punti Puntius sophore on fish polyculture production

A sustainable semi-intensive pond aquaculture technology including major carp species as cash-crop and small indigenous fish species (SIS) as food for the farmers' families is being optimized in Bangladesh. The inclusion of silver carp (Hypophthalmichthys molitrix), a cheap large species affordable by poor farmers, is now being considered. As part of a study on the effects of this filter feeder on polycultures including the large carps rohu (Labeo rohita), catla (Catla catla) and common carp (Cyprinus carpio) and the SIS punti (Puntius sophore) and mola (Amblypharyngodon mola), an experiment was carried out under farm conditions to test the effects of silver carp and of each SIS species on the growth, survival and yield of the large and small species and on pond ecology.The experiment was performed in 38 farmers' fishponds of different sizes, from 220 m² to 1200 m². The results show that the larger the fish pond the better rohu performance, the larger punti fry weight and the lower punti fry harvested biomass. Pond size did not affect other fish species. The addition of 250 mola and/or punti per 100 m² fishponds affected rohu and catla and did not affect common and silver carps. The addition of mola alone reduced rohu's parameters by 15%. The addition of SIS in the three combinations tested (250 mola, 250 punti, 125 of each species) reduced catla's parameters by 20-24%. Punti fry were larger when both SIS were stocked and punti fry biomass was larger when only punti were present. Total mola harvested biomass and yield were larger when the entire SIS stocked were only mola.The addition of 10 silver carp over the 99 large carps stocked per 100 m² fishponds negatively affected rohu and catla growth and yield by about 15-21% and 45-50% respectively but not their survival, did not affect common carp performance, did not affect punti and mola reproduction in the ponds, reduced punti yields by 25%, reduced mola performance by about 35%, and silver carp own biomass increased total yield and total income in about 12% each. These effects are explained and discussed considering fish interactions through the food web. The decreased income from selling the more expensive large carps is more than compensated by that obtained from silver carp, which allows the option to the farmer to sell part of the silver carp to complete the cash income that would have been obtained from large carps only if silver carp would not be stocked, and consume the rest with the family.     

Antinutritive effects of galactomannan-rich endosperm of Sesbania (Sesbania aculeata) seeds on growth and feed utilization in tilapia, Oreochromis niloticus

An 8‐week feeding trial was conducted using tilapia, Oreochromis niloticus L., in a recirculation system maintained at 27±0.2°C to observe the negative effects of Sesbania endosperm on growth and nutrient utilization. Five experimental diets were formulated to contain 32% protein, of which fishmeal was the major source. Endosperm separated from Sesbania seeds was included at levels of 0.0%, 2.9%, 5.8%, 8.7% and 11.6% in diets 1 (control), 2, 3, 4 and 5, respectively, equivalent to levels of 0.0%, 9.7%, 19.4%, 29.1% and 38.8%, respectively, of whole Sesbania seeds. Each treatment had two replicates, eight fish per replicate, with a mean initial live weight of 5.2±0.1 g. Fish were fed 20 g per kg metabolic body weight of fish daily. The body weight gain, metabolic growth rate, feed conversion ratio, protein efficiency ratio, protein productive value and energy retention of fish fed the control and diet 2 were significantly better (P<0.05) than those of fish fed the other diets. Physical observation showed that the intestines of the fish fed diets that included endosperm contained loose, viscous and sticky material. Fish fed diets 3, 4 and 5 had a lower proportion of dry matter in their faeces, and lower apparent crude lipid and energy digestibility coefficients compared with fish fed the control diet and diet 2. They also had significantly reduced levels of muscle and plasma cholesterol, whole‐body crude protein, lipid and gross energy.     

Economic dependence of rural people on homestead forestry in Mymensingh, Bangladesh

Homestead forests contribute substantially to the rural economy of Bangladesh. Rural people depend on trees and plants for their energy usage, housing, food and other forms of subsistence livelihood. In order to identify the potential role of forests on homestead dwellers, an empirical field investigation was conducted in the four Upazilas of Mymensingh district of Bangladesh. It was found that land holdings of the respondents within the four sites are the highest in Mymensingh. The study made an important observation that among all homestead vegetation between 5–6 years old, tree species are generally preferred over plants. This is perhaps due to the efforts of the social forestry extension service to demonstrate that planting trees is an important long-term investment. In all four Upazilas, there was a significant correlation between household annual income and homestead forestry, agriculture and fisheries practice, suggesting that higher income families tend to have larger holdings of homesteads, farms and pond areas. Three Upazilas displayed a strong positive relationship (nearly 45%) between homestead forest areas and annual family income; however, the Fulbaria Upazila showed a very poor relationship (0.2%) in this regard. The results of this study suggest that homestead forests play a positive role in the rural economy, in addition to helping mitigate the increasing problem of deforestation in Bangladesh.     

Improving Acacia auriculiformis seedlings using microbial inoculant （Beneficial Microorganisms）

A microbial inoculant, known as effective microorganisms(EM), was applied to determine its efficacy on seed germination and seedling growth in the nursery of Acacia auriculiformis A Cunn. ex Benth. The seedlings were grown in a mixture of sandy soil and cow dung(3:1) and kept in polybags; EM was poured at different concentrations(0.1%, 0.5%, 1%, 2%, 5% and 10%). Seed germination rate and growth parameters of seedlings – shoot and root lengths, fresh and dry weights of shoots and roots, vigor, volume, and quality indices and sturdiness – were measured. The nodulation status influenced by EM was also observed, along with the measurement of pigment contents in leaves. The highest germination rate(72%) was observed in 2% EM solution while the lowest(55%) was found in control treatment. The highest shoot and root lengths(30.6 cm and 31.2 cm respectively) were recorded in 2% EM and were significantly(p 0.05) different from control. Both fresh and dry weights of shoots were maximum(8.66 g and 2.99 g respectively) in 2% EM, whereas both fresh and dry weights of root were maximum(2.56 g and 1.23 g respectively) in 5% EM solution. Although the highest vigor index, volume index, and sturdiness(4450, 628 and 67.5 respectively) were found in 2% EM, the highest quality index(0.455) was found in 5% EM solution. The nodule number was higher at a very low(0.5%) concentration of EM but it normally decreased with the increase of concentration. The contents of chlorophyll a, chlorophyll b, and carotenoid were maximum(43.26 mg?L-1, 13.56 mg?L-1and 17.99 mg?L-1 respectively) in 2% EM. Therefore, low concentration of EM(up to 2%)can be recommended for getting maximum seed germination and seedling development of A. auriculiformis in the nursery.     

Effects of shifting cultivation on biological and biochemical characteristics of soil microorganisms in Khagrachari hill district,Bangladesh

We collected soil samples from two representative sites at Aatmile of Khagarachari hill district in Chittagong Hill Tracts. One of the sites was under shifting cultivation and the other an adjacent 13-year old teak plantation. Both sites were in the same physiographic condition and same aspect with parable soil type, which enabled us to measure the effects of shifting cultivation on soil micro-flora. We studied soil physico-chemical properties and the biochemical and biological properties of soil microbes. Moisture and organic matter content as well as fungi and bacterial populations, both in surface and subsurface soils, were significantly(p ≤0.001) lower in shifting cultivated soils compared to soils not under shifting cultivation, i.e. the teak plantation site. The most abundant bacteria in surface(0-10 cm) and sub-surface(10-20 cm) soils under shifting cultivation were Pseudomonas diminuta and Shigella, respectively, while in corresponding soil layers of teak plantation, predominant microbes were Bacillus firmus(0-10 cm) and Xanthomonas(10-20 cm). The microbial population differences cannot be explained by soil texture differences because of the textural similarity in soils from the two sites but could be related to the significantly lower moisture and organic matter contents in soils under shifting cultivation.     

A Study of Indoor Environment Indicators in Popular Green Building Assessment Systems

A comparison research is launched for the Indoor Environment Quality indicators of the popular Green Building Assessment systems and China Evaluation standard for green building, including the IEQ indicators’ contents, weightings, and the scoring requirements for different green building ratings. By comparison, it was found that the indoor environment is mainly composed by IAQ, version environment, thermal environment and the acoustic environment, and the IAQ is the most important component in these systems. Although there is no weighting system or scoring system in China Green building assessment system, it is characterized by the relatively numerous prerequisites and the achieved indicators requirement for different ratings. Besides, the indicators paid with intensive attention in these systems are found.     

Gastro-oesophageal reflux in halothane anaesthetized sheep. The effects of feeding and positioning

The frequency of gastro-oesophageal reflux (GOR) in sheep anaesthetized with halothane was reduced by withholding food and water for 24 hours. The total reflux volume increased. The effect of body position on GOR was studied by inclining the operating table at angles to the horizontal and positioning the head up or down on sand bags. The operative positions investigated were: right and left lateral recumbency with head down, dorsal recumbency with head down and right lateral recumbency with head up. Least GOR occurred when the sheep was in right lateral recumbency with a head up tilt and the body inclined at 20° from the horizontal. A cuffed oesophageal drainage tube increased the incidence of GOR but prevented the chances of the aspiration of rumen material.     

Influence of temperature levels and planting time on the sprouting of rhizome-bud and biomass production of torpedograss (Panicum repens L.) in Okinawa island, southern Japan

The present study describes the influence of temperature levels and planting time on the sprouting of rhizome-buds and the biomass production of torpedograss ( Panicum repens L.) in the Okinawa prefecture, Japan. Torpedograss planted in each month (1994–95) was grown for 210 days. Sprouting of the rhizome-bud of torpedograss was 92–96% at the temperature range of 20–35°C in an incubator, and the sprouting was not observed at the extreme low and high temperature of ≤5 and ≥45°C, respectively. The plant showed 40–72% emergence when grown in pots throughout the year in the ambient temperature range of 17–29°C. The percentage emergence was comparatively higher in March to September, and shoots elongated rapidly in the period from April to October when the temperature range of 22–29°C prevailed. Torpedograss-rhizome sown in the period from January to June obtained significantly higher biomass because higher temperatures prevailed in the following growth period from May to October, as compared with the torpedograss-rhizome sown in the period of July to December. The plant required higher temperatures for proper growth and development during the period of moderate (70–110 days after planting (DAP)) and fast growth phases (110 DAP to the last harvest).     

Expression of glial cells molecules in the optic nerve of adult dromedary camel (Camelus dromedarius): A histological and immunohistochemical analysis

The optic nerve (ON) is an important organ in the visual system of animals, which transfers electrical impulses towards the brain from the retina. High enrichment of glial cells in ON is known to support neuron and regulate retinal homoeostasis. However, research on immunohistochemical of glial cells proteins in the camel is scanty in available literature. Hence, the current work is an attempt to investigate the histomorphology of camel ON with regard to the expression patterns of glial fibrillary acidic protein (GFAP), myelin basic protein (MBP) and Iba1 for the three glial subtypes, namely astrocytes, oligodendrocytes and microglia, respectively. Optic nerves from fourteen dromedary camels were dissected and preserved in 10% formalin. Then, the paraffin‐embedding sections were subjected for histochemical and immunohistochemical analysis. Our results demonstrated that ON axons aggregate into fascicles that surrounded by light and densely stained glial cells. Then, we examined the myelin sheath using Heidenhain's and Mallory's phosphotungstic acid staining. Immunoassay results revealed that GFAP is enriched in the ON and distributed evenly, whereas MBP and Iba1 were present at scanty levels. Further analysis of mRNA level of GFAP, MBP and Iba1 in the ON confirmed an elevation of GFAP expression compared to MBP and Iba1. We further found partial co‐localization of different types of glial cells that reflect their coordinated function in the ON. Although our data provide the first evidence for differential expression pattern of glial proteins, further molecular studies still required to reveal the specific function of these molecules in the camel ON.