The basics of bio-flocs technology: The added value for aquaculture

A systematic revision of the African species of the genus Clarias (Pisces;Clariidae) , A systematic revision of the African species of the genus Clarias (Pisces;Clariidae) , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

A Systematic Revision of the African Species of the Genus Clarias (Pisces; Clariidae)

Tilapia are the second most farmed fish worldwide and their production has quadrupled over the past decade due to ease of aquaculture, marketability and stable market prices. Tilapia aquaculture must adopt sustainable practices (such as polyculture) for continuing increased production and improved sustainability. This article reviews tilapia polyculture around the world and discusses its benefits, strategies and practices. Tilapia polyculture improves feed utilization, enhances water quality, increases total yield and profit. Further investment will increase these gains. Research on tilapia polyculture in China was also summarized and addressed that polyculture in semi-intensive systems was a way of improving sustainability for tilapia aquaculture.

Tilapia polyculture: a global review.

A nutrition trial was conducted to investigate the effects of dietary lipid levels and supplemental Ulva meal on growth performance, feed efficiency, nutrient utilization, and body composition of juvenile Nile tilapia, Oreochromis niloticus. Four isonitrogenous (CP 40%) diets containing 0% and 5% Ulva meal were formulated to contain 10% (low-lipid; LL) and 20% (high-lipid; HL) crude lipid. Triplicate groups of fish (~10 g) were fed to apparent satiation three times daily for 16 weeks. Fish fed 5% Ulva meal showed an increased growth performance (P < 0.05) compared with fish fed non-Ulva supplemented diets, irrespective of dietary lipid level. In particular, the incorporation of Ulva meal improved specific growth rate (SGR), feed conversion ratio (FCR), and protein efficiency ratio (PER). Feeding fish 5% Ulva meal diets resulted in significantly lower carcass lipid content. The results indicate that 5% inclusion of Ulva meal at both dietary lipid levels improves growth performance, feed efficiency, nutrient utilization, and body composition of Nile tilapia.

https://www.yalova.edu.tr/Files/Import/ucgen3/userfiles/file/paper/s_e_.pdf

Influence of Ulva meal on growth, feed utilization, and body composition of juvenile Nile tilapia (Oreochromis niloticus) at two levels of dietary lipid

Trabajo presentado en la 113th General Meeting of the American Society for Microbiology, celebrada en Denver, Estados Unidos, del 18 al 21 de mayo de 2013

Species concept for prokaryotes

An experiment was conducted to evaluate the eiect of using diierent types of organic manure on the plankton abundance, and growth and survival of Tilapia rendalli juveniles in ponds. Fish weighing18.15 0.44 g were stocked into 12, 20 m 2 ponds at 2 ¢sh m 2 (40 ¢sh pond 1 ). There were three replicate ponds per treatment (chicken manure, cattle manure, pig manure, and no-manure as a control). After 84 days the T. rendalli in the chicken manure treatment were signi¢cantly larger and had higher net annual yields than those in the cattle manure, pig manure and nomanure treatments. The survival rates were not signi¢cantly diierent across the treatments. Signi¢cantly higher amounts of chlorophyll a and higher numbers of zooplankton were found in ponds fertilized with the chicken manure treatment. The overall results obtained in this study suggest that the use of chicken manure produces better results than cattle and pig manure treatments on unfertilized ponds.

/pdf/effect-of-using-different-types-of-organic-animal-manure-on-3aowhppg95.pdf

Effect of using different types of organic animal manure on plankton abundance, and on growth and survival of Tilapia rendalli (Boulenger) in ponds

Juvenile T. rendalli were evaluated for 10 weeks to determine the effect of salinity on growth, feed utilization, and survival in tanks. Fish weighing 3.94 ± 0.44 g were stocked into twelve 50-L rectangular tanks at 15 fish /tank. The fish were raised in three salinity levels (5, 10, 15‰, and freshwater as a control). There were three replicate tanks per treatment. After the feeding experiment, a digestibility trial was conducted for two weeks. After 70 days, fish in the 10‰ treatment grew significantly larger (P < 0.05) than those in 5‰, 15‰, and freshwater. T. rendalli cultured in 10‰ had significantly lower feed conversion ratios and higher feed conversion efficiency and protein efficiency ratios. Survival of the fish was significantly (P < 0.05) different and depended on salinity level. The apparent digestibilities of crude protein, fat, ash, and gross energy were significantly higher (P < 0.05) in T. rendalli cultured in the 10‰ salinity treatment. However, apparent digestibility of dry matt...

Effect of Salinity on Growth, Feed Utilization, and Survival of Tilapia rendalli Under Laboratory Conditions

Nutrient composition analysis was conducted for selected locally available plant based feedstuffs from Mpamba area in NkhataBay district of northern Malawi. The objective was to identify and isolate those that can be used as ingredients in the formulation of affordable and quality fish feeds to increase pond based fish production in Malawi. The following plant based feedstuffs were collected: Cassava (Manihot esculenta) peels (CP) and leaves (CL) Pawpaw (Carica papaya) leaves (PL), Sweet potato (Ipomea batatus) leaves, meal and tubers (SPL), (SPP) and (SPM) Jackfruit (Artocarpus heterophyllus) (JF), Mexican fireplant (MF) (Euphorbia heterophylla), Black jack (Bidens pilosa) (BJ), Banana (Musa balbisiana) leaves (BL), Maize (Zea maise) bran (MZB), and Akee (Blighia sapid) leaves (AK). Results showed that Cassava (Manihot esculenta) leaves, Black jack (Bidens pilosa) and Cocoyam (Caladium bicolor) leaves contain significantly high levels of crude protein: 21.17 ± 0.56%, 24.35 ± 0.7% and 24.28 ± 0.11% respectively. Energy levels ranged from 29.7 kj/g to 8.78 kj/g for Sweet potato leaves and cassava peels respectively. In addition, all plant feedstuffs had low levels of crude fiber ranging from 3.78 ± 0.20% to 16.84 ± 0.26%. Depending on their availability, potential, competition for other uses, crude protein, energy, crude fiber levels, most of the leaves analyzed demonstrated to be potential sources of fish feed. This suggests that while leaves have been utilized in low input aquaculture systems, they may serve as feeds for fish once the plant feedstuffs are appropriately incorporated in formulated diets and alternatively as organic fertilizers.

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Nutritional Value of Locally Available Plants with Potential for Diets of Tilapia Rendalli in Pond Aquaculture in NkhataBay, Malawi

The aim of this study was to assess quality of Lake Malawi Tilapia (local name: Chambo) from local and super markets in Malawi. Fish from local markets hadsignificantly higher numbers of viable bacteria counts(9.5× 10 8 CFU/g, cm 2 ) (P<0.01)which were above acceptable limits compared to fish from super markets(2.7× 10 5 CFU/g, cm 2 ).Most isolated bacteria species were Corynebacterium, Micrococcus, Pseudomonas, Bacillus, Flavobacterium and Escherichia coli. Mean total volatile basic nitrogen (TVBN), trimethylamine nitrogen (TMA-N) (g/100mg) and pH of fish from local and super markets were 15.40±0.00, 0.10±0.01, 6.11±0.12 and 14.90±0.58, 0.13±0.02, 6.20±0.07, respectively.Fish collected from local markets had significantly higher levels of TVB-N (P<0.05)compared to those from super markets. Fish from both local and super markets were contaminated generally due to poor handling by sellers but not necessarily at the selling points. The study nevertheless observed that despite being microbiologically contaminated, fish were not wholly spoiled. This suggests that product declared unfit for consumption through sensory evaluation may still be nutritionally good hence need for validating such results with other methods.

Quality Assessment of Fresh Lake Malawi Tilapia (Chambo) Collected from Selected Local and Super Markets in Malawi.

An experiment was carried out to determine the eiect of substituting maize bran with chicken manure on the production of Tilapia rendalli semi-intensive pond culture. The experiment was carried out at Bunda College of Agriculture’s ¢sh farm, University of Malawi, where twelve 20 m 2 concrete ponds of 1m depth were used

/pdf/effect-of-substitution-of-maize-bran-with-chicken-manure-in-2ieggwnfiz.pdf

Jeremiah Kang'ombe

Papers

Effect of using different types of organic animal manure on plankton abundance, and on growth and survival of Tilapia rendalli (Boulenger) in ponds

Effect of Salinity on Growth, Feed Utilization, and Survival of Tilapia rendalli Under Laboratory Conditions

Nutritional Value of Locally Available Plants with Potential for Diets of Tilapia Rendalli in Pond Aquaculture in NkhataBay, Malawi

Quality Assessment of Fresh Lake Malawi Tilapia (Chambo) Collected from Selected Local and Super Markets in Malawi.

Effect of substitution of maize bran with chicken manure in semi-intensive pond culture of Tilapia rendalli (Boulenger)