Effects Of Artificial Substrates Research Articles

Effect of paddy straw and sugarcane bagasse on growth and survival of giant freshwater prawn Macrobrachium rosenbergii (de Man, 1879)

Effect of artificial substrates on growth and survival of giant freshwater prawn Macrobrachium rosenbergii (de Man, 1879)in the nursery and grow-out rearing was evaluated. Nursery rearing was conducted for a period of 35 days in nine 1 m3cement tubs with 15 cm soil base. Three tubs without substrates served as control (C) while three tubs each with 200 g ofsugarcane bagasse (SB) or 200 g of paddy straw (PS) formed the treatments. Each tub was stocked with 15 post-larvae(mean weight, 0.01 g). Grow-out rearing was conducted for 90 days in six 25 m2 cement cisterns, of which three cisternswithout substrate served as control (C) and three with 5 kg sugarcane bagasse (SB) served as treatment. Each cistern wasstocked with 25 juveniles (mean weight, 0.55 g). The average phytoplankton and zooplankton abundance in water as wellas algae and food organisms attached on the substrate in the nursery phase was greater in bagasse than in paddy strawtreatments. Addition of substrate resulted in higher growth and survival both in nursery and grow-out phase. Prawns grownin cisterns provided with substrates were of more uniform size than those in control cisterns. The study recommends the useof substrate based aquaculture for nursery and grow-out rearing of M. rosenbergii.

Artificial substrates in zero-water-exchange culture system regulate the rearing performance of Pacific white shrimpLitopenaeus vannamei(Boone, 1931) under the winter indoor condition

Effects of artificial substrates in zero-water-exchange culture system on the rearing performance of Litopenaeus vannamei under winter indoor condition were investigated in this study. Growth, survival, feed conversion rate (FCR), production rate of L. vannamei and water quality were compared between artificial substrate-treated group (AST) and control group (without artificial substrates presented in the rearing environment). Artificial substrates can significantly improve the water quality, the ammonia and nitrite-N concentrations in the AST group were significantly lower than in the control group (P < 0.05), and the total heterotrophic bacteria and Vibrio spp. were also significantly lower in the AST group (P < 0.05). The survival, growth and production rate of L. vannamei in the AST group were significantly higher than in the control group (P < 0.05). Significantly lower FCR was observed in the AST group (P < 0.05). Results from this study indicate that the utilization of artificial substrates in the indoor shrimp culture system could effectively control the water quality, improve the survival and growth of shrimp and significantly reduce the FCR. This study provides a guideline for employing artificial substrates in rearing of shrimp in the zero-water-exchange culture system under lower temperature, which could be applicable to other similar species.

Use of artificial substrate in pond culture of freshwater prawn (Macrobrachium rosenbergii): a new approach regarding growth performance and economic return

An experiment was conducted for six months to evaluate the effects of artificial substrates on the survival, growth and production of Macrobrachium rosenbergii juveniles. The T1 contained locally available bamboo-made substrate both vertical and horizontal and T2 received no substrate. Juvenile prawns (0.40±0.13 g) were stocked at the rate of 19,760 prawns ha-1. The water quality parameters range such as temperature, pH and DO were 22.06-33.45°C, 7.70-8.40 and 4.75-6.15 mgl-1 respectively which was no significant difference (P&lt;0.05) between two treatments. The final weight was 56.48±6.56 g and 45.03±2.11 g in T1 and T2 respectively. The survival rate of T1 was 63.12% which was significantly higher (P&gt;0.05) than T2 (56.87%). The specific growth rate, food conversion ratio and protein efficiency ratio were 1.19 % and 1.14 %, 3.15 and 4.39, 0.98 and 0.71 in T1 and T2 respectively which were not significantly different (P&lt;0.05) between treatments. The total production and net profit in T1 was 1408 kgha-1 and BDT 117,325 ha-1 which was significantly higher (P&gt;0.05) than T2. Thus growth and survival of prawn juveniles improved in presence of artificial substrate which could be economically viable technique for the freshwater prawn culture.

Water quality, production parameters and nutritional condition of Litopenaeus vannamei (Boone, 1931) grown intensively in zero water exchange mesocosms with artificial substrates

The effect of artificial substrates on the water quality, production parameters and nutritional condition was assessed in experimental intensive cultures of Litopenaeus vannamei grown in mesocosm units with zero water exchange. The initial stocking densities in triplicate 1000 L tanks were 600 and 800 g of juvenile shrimp (2.7 g) per unit, with (W) and without (WO) artificial substrates. There were no significant differences between the water quality parameters of the four treatments. In the tanks with the lower stocking biomass, the best survival (96.7% vs. 87.0%), growth rate (1.69 vs. 1.35 g week−1), final biomass (1969.6 vs. 1516.0 g m3) and feed conversion ratio (1.30 vs. 1.90) were obtained with artificial substrates. Similar results were observed for the higher stocking biomass (90.9% vs. 74.5%, 1.50 vs. 1.13 g week−1, 2221.6 vs. 1560.8 g m3, and 1.50 vs. 2.60 respectively). The nutritional condition of shrimp was improved using artificial substrates. The protein content in muscle was higher (21.6% and 20.4%) in ponds with substrates as compared with the control (21.2% and 15.9%).

Overview of recent research and development in temperate culture of the freshwater prawn (Macrobrachium rosenbergii De Man) in the South Central United States

Research and development efforts concerning freshwater prawn farming have in the past been principally conducted in tropical regions. However, activities in temperate regions also date back several decades. Culture of Macrobrachium in temperate zones offers positive opportunities, despite the inability to culture year-round. Unique problems imposed by a restricted growing season must be addressed, and opportunities capitalized on, to attain commercially viable production in these regions. Much recent research in the South and Central USA has been directed towards intensifying production (kg ha−1) without decreasing average harvest sizes or deteriorating water quality. Particular areas of research include evaluating and maximizing the relative contributions of natural foods, effects of artificial substrates on growth and prawn population structure and grading of animals before pond stocking to reduce heterogeneous individual growth and aggressive interactions. Recent studies have concentrated on combining these factors into a ‘best management practices’ (BMPs) production model. With these factors combined, production has increased from an average of 1000 kg ha−1 of 30 g animals to almost 3000 kg ha−1 of 40 g animals produced in research ponds in 110 days of culture. In commercial ponds, 1500–2000 kg ha−1 has been achieved in a similar period using BMPs.

The effects of artificial substrates on freshwater pond productivity and water quality and the implications for periphyton-based aquaculture

As a first step in assessing the viability of periphyton-based fish production in South Asian pond aquaculture systems, the effects of artificial substrates on development of periphyton and on water quality were evaluated. Earthen ponds (10 × 7.5 m) were provided with an artificial substrate constructed from poles of either bamboo, kanchi or hizol tree branches (1.0 m 2 artificial substrate per m 2 pond surface). Higher periphyton biomass, in terms of dry matter (DM) (4.9 mg cm –2) and chlorophyll a (11.5 μg cm –2) developed on hizol and bamboo, respectively. Periphyton ash content was higher on hizol (41%) than on the other two substrate types (29%). Protein content of the periphyton growing on bamboo (38% of ash-free dry matter (AFDM)) was 50% higher than that on the other two substrate types. Maximum periphyton productivities of 1.01, 1.38 and 1.03 g C m –2 d –1 were obtained for bamboo, hizol and kanchi substrates, respectively. Taxonomic composition of periphyton showed a rapid development of a relatively stable community with few differences between the substrate types. In total, 56 genera of algal periphyton and 35 genera of phytoplankton were identified. Based on a periphyton productivity estimate of 2.2–2.8 g AFDM m –2 d –1, periphyton alone can sustain an estimated fish production of 5000 kg ha –1 year –1 through the addition of a substrate area equivalent to 100% of the pond surface area.

The effect of artificial substrates and host extracts on oviposition by Callosobruchus maculatus (F.) (Coleoptera: Bruchidae)

Callosobruchus maculatus will oviposit on a wide variety of seeds and other surfaces. A simple bioassay is described for testing stimulants or deterrents which may affect where, and in what quantity, eggs will be deposited. Glass beads, 6.5–7.5 mm in diameter, coated with an extract of cowpeas provided a surface for oviposition which was as attractive to female beetles as untreated cowpea seeds in terms of the number of eggs laid. However, beetles laid fewer eggs when the beads could roll around than when this was prevented. When extracts were prepared by soaking whole cowpeas with unbroken testae in acetone for periods between 10 min and 24 hr no differences were found in the stimulatory effect among the extracts prepared, and in every case the level of egg-laying was the same as that on normal cowpeas. Eggs laid on the coated beads were, however, more uniformly distributed than the eggs laid by comparable beetles on cowpeas.