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41.
Mohammad T Ridha 《Aquaculture Research》2004,35(11):1031-1038
The reproductive performance and seed production of three mouth‐brooding tilapia species, Oreochromis spilurus (Günther), Oreochromis aureus (Steindachner) and Taiwanese red tilapia hybrid, were compared in low‐salinity underground water (3–5 g L?1) to select species with the highest reproductive rate. Two‐year‐old males and females having average body weights of 454 and 259 g, respectively, were stocked in 2‐m3 fibreglass breeding tanks (two tanks per species) at 1:3 male to female sex ratio and at average density of three fish m?2. Seeds (unhatched eggs; yolk‐sac fry and the swim‐up fry) were collected weekly for 112 days. The results showed O. spilurus to have significantly higher (P<0.05) mean spawning parameters expressed as total seed tank?1 (84 154), seed kg female?1 day?1 (284), seed m?2 day?1 (190.3) and seed female?1 day?1 (76.3), than O. aureus and red tilapia. Monthly seed production in O. spilurus and red tilapia gradually increased from May, peaked in July and declined in August, while in O. aureus, it continued to decrease from May to August. In this study, the observed production levels of seed in O. spilurus were among the highest levels reported for tilapia; therefore, O. spilurus could be selected as a potential candidate for mass seed production in commercial tilapia hatcheries. 相似文献
42.
An experiment was conducted for 60 d in a recirculatory system consisting of 20 glass aquariums (each of size 41 × 41 × 46 cm) to evaluate meat and bone meal (MBM) as partial replacement for fish meal (FM) in Macrobrachium rosenbergii postlarvae (PLs) with a view to develop an inexpensive nursery diet. Three nursery diets were formulated to contain 32% protein and to be as isoenergetic as possible. FM in these diets was progressively replaced with MBM (Diet 1 contained 25% FM and 14% MBM, Diet 2 contained 20% FM and 20% MBM, and Diet 3 contained 15% FM and 26% MBM). Inclusion levels of mustard oilcake and sesame meal in diets were kept fixed at 10%. A commercial shrimp nursery diet (30% protein) from Saudi Bangla Fish Feed Ltd., Mymensingh, was used as the reference diet (Diet 4). Each treatment had three replicates. PLs of M. rosenbergii (26 ± 0.02 mg) were stocked at the rate of 60 PLs (1 PL/L) in each aquarium. At the beginning, PLs were fed three times daily at a rate of 20% of the body weight and it was gradually reduced to 10% at Day 30. The ranges of water quality parameters in the system were as follows: temperature, 27–29 C; dissolved oxygen, 6.5–8.4 mg/L; pH, 6.8–8.3; and total ammonia, 0.01–0.15 mg/L. The result of the study showed that there was no significant difference (P > 0.05) between the weight gains of PLs fed Diet 1 (containing 14% MBM) and Diet 4 (reference diet) but was significantly higher than other dietary groups containing higher levels of MBM. Diets 1 and 4 showed significantly lower (P < 0.05) apparent food conversion ratios (1.74 and 1.73, respectively). The survival (%) of PLs ranged between 62 and 76% with PLs fed Diets 1 and 4 showing significantly higher (P < 0.05) survival. The result of the study demonstrated that the MBM could be included at 14% level in a nursery diet, and a diet containing 25% FM, 14% MBM, 10% sesame meal, and 10% mustard oilcake may be recommended for profitable production of PLs of M. rosenbergii. 相似文献
43.
David E. Kime Mohammad A. S. Abdullah Miroslawa Sokolowska-Mikolajczyk Piotr Epler 《Fish physiology and biochemistry》1994,13(4):317-324
Carp ovarian tissue was incubated with 3H-17-hydroxyprogesterone in the presence of 0, 0.1, 1, 10, and 100 μg ml−1 unlabeled 17-hydroxyprogesterone. The pattern of metabolites formed showed a marked variation with substrate concentration.
Formation of glucuronide and sulphate conjugates was important only at low substrate concentration. At high substrate concentration
(10 and 100 μg ml−1) 17,20α-dihydroxy-4-pregnen-3-one was the major metabolite, but at intermediate concentrations polar 7α-hydroxypregnanetetrols
predominated. The results support the hypothesis that at low substrate concentrations conjugating, 5α-reducing and 7α-hydroxylating
enzymes, of high activity but low capacity, act as scavengers to deactivate any steroids formed during the relatively low
pituitary gonadotrophin secretions which are necessary for oocyte development, but that during the prespawning gonadotrophin
surge when high levels of substrate are present these enzymes are saturated and 17,20α-dihydroxy-4-pregnen-3-one (17,20αP)
becomes the major ovarian steroid. The possible role of 17,20αP during oocyte final maturation requires further examination. 相似文献
44.
Mostafa A R Hossain Graham S Haylor & Malcolm C M Beveridge 《Aquaculture Research》2001,32(12):999-1004
The effects of feeding time and frequency on the growth, feed utilization and survival of Clarias gariepinus (Burchell 1822; family Clariidae) fingerlings were evaluated in a 25-day study. Groups of African catfish with an initial individual weight of 0.98 ± 0.02 g were offered feeds continuously for 24 h, or during the day or night at different time intervals, with varying meal size. The growth rate was significantly affected by meal times. Widely practised day time feeding with three equal size meals a day gave the lowest growth and highest food wastage. The growth rates of fish fed continuously or during night time following their feed demand were significantly higher with lowest food conversion ratios and food wastage. 相似文献
45.
Marine sponges belonging to the phylum Porifera (Metazoa), evolutionarily the oldest animals are the single best source of marine natural products. The present review presents a comprehensive overview of the source, taxonomy, country of origin or geographical position, chemical class, and biological activity of sponge-derived new natural products discovered between 2001 and 2010. The data has been analyzed with a view to gaining an outlook on the future trends and opportunities in the search for new compounds and their sources from marine sponges. 相似文献
46.
Anabat Mohammad Mohebi Sheidai Masoud Riahi Hossein Koohdar Fahimeh 《Genetic Resources and Crop Evolution》2022,69(2):855-870
Genetic Resources and Crop Evolution - The genus Crocus of the family Iridaceae is a monophyletic genus with over 100 species. Due to the high degree of hybridization and the changes in the number... 相似文献
47.
Fayaz Humara Mir Asma Hamid Tyagi Sandhya Wani Aijaz A. Jan Nelofar Yasin Mohammad Mir Javid Iqbal Mondal Biswajit Khan Mohd Anwar Mir Reyazul Rouf 《Genetic Resources and Crop Evolution》2022,69(3):1193-1205
Genetic Resources and Crop Evolution - Cicer arietinum L. (chickpea) is one of the most significant legume crops domesticated in the Fertile Crescent. This study was aimed to characterize a diverse... 相似文献
48.
Shahsavari Shiva Noormohammadi Zahra Sheidai Masoud Farahani Farah Vazifeshenas Mohammad Reza 《Genetic Resources and Crop Evolution》2022,69(3):1207-1217
Genetic Resources and Crop Evolution - The pomegranate (Punica granatum L.) is an ancient fruit plant which has been consumed for its nutritional value and medicinal properties by mankind. Several... 相似文献
49.
Nasrin SULTANA Jun ZHAO Yuanfeng CAI G. K. M. Mustafizur RAHMAN Mohammad Saiful ALAM Mohammad FAHEEM Adrian HO Zhongjun JIA 《土壤圈》2022,32(2):348-358
Biological methane oxidation is a crucial process in the global carbon cycle that reduces methane emissions from paddy fields and natural wetlands into the atmosphere.However,soil organic carbon accumulation associated with microbial methane oxidation is poorly understood.Therefore,to investigate methane-derived carbon incorporation into soil organic matter,paddy soils originated from different parent materials(Inceptisol,Entisol,and Alfisol) were collected after rice harvesting from four major rice-producing regions in Bangladesh.Following microcosm incubation with 5%(volume/volume)13 CH4,soil13 C-atom abundances significantly increased from background level of 1.08% to 1.88%–2.78%,leading to a net methane-derived accumulation of soil organic carbon ranging from 120 to 307 mg kg-1.Approximately 23.6%–60.0% of the methane consumed was converted to soil organic carbon during microbial methane oxidation.The phylogeny of13 C-labeled pmoA(enconding the alpha subunit of the particulate methane monooxygenase) and 16 S rRNA genes further revealed that canonical α(type II) and γ(type I) Proteobacteria were active methane oxidizers.Members within the Methylobacter-and Methylosarcina-affiliated type Ia lineages dominated active methane-oxidizing communities that were responsible for the majority of methane-derived carbon accumulation in all three paddy soils,while Methylocystis-affiliated type IIa lineage was the key contributor in one paddy soil of Inceptisol origin.These results suggest that methanotroph-mediated synthesis of biomass plays an important role in soil organic matter accumulation.This study thus supports the concept that methanotrophs not only consume the greenhouse gas methane but also serve as a key biotic factor in maintaining soil fertility. 相似文献
50.
HYDRUS simulations of the effects of dual-drip subsurface irrigation and a physical barrier on water movement and solute transport in soils 总被引:2,自引:1,他引:1
Subsurface drip irrigation systems, compared to other irrigation systems, enhance the delivery of water and nutrients directly into the root zone. However, in light-textured soils, certain quantities of water may percolate below the root zone due to the subsurface position of drip lines and/or poor management of irrigation systems. The main objective of this paper is to evaluate three technologies to enhance a spatial distribution of water and solutes in the root zone and to limit downward leaching. The three technologies include (a) a physical barrier, (b) a dual-drip system with concurrent irrigation, and (c) a dual-drip system with sequential irrigation. To achieve this objective, we performed computer simulations using the HYDRUS (2D/3D) software for both bare and vegetated soils. The results indicate that the physical barrier is more efficient than dual-drip systems in enhancing the water distribution in the root zone while preventing downward leaching. On the other hand, the dual-drip system improves water distribution in sandy soils. Additionally, the dual-drip system with sequential irrigation, followed by the dual-drip system with concurrent irrigation, is the most efficient in limiting downward leaching of solutes. 相似文献