Low-cost Fish Research Articles

PRODUCTION OF A LOW COST FISH DIET BY USING POULTRY BY-PRODUCTS RESIDUES

This study aimed to produce a low cost fish diet through using levels of poultry by-products meal in diets of Nile tilapia (Oreochromis niloticus). The experiments were carried out through 90 days and included five treatments of 0, 25, 50, 75 and 100% poultry by-products. The highest weight gain WG (59.84 g) was recorded for fish fed on the control diet followed by those fed on the diet 25% (53.37 g), 50% (52.98 g), 75% (48.46g) and 100% (46.22 g) replacement, respectively. The differences in weight gain among the different fry groups were significant (P<0.05) and the same trend was observed for specific growth rate SGR. The average feed intake, feed conversion ratio and protein efficiency ratio of Nile tilapia were significantly (P<0.05) affected by the incorporation of poultry by-products meal as a substitute of fish meal. The results of this study showed that moisture in whole fish body ranged between 77.40 and 80.55% with insignificant differences. Crude protein ranged between 61.70 and 64.44%, ether extract ranged between 15.50 to 17.73% and ash from 17.84 to 22.43% with significant differences for ether extract and protein content of whole fish bodies. Feed cost decreased as inclusion levels of poultry by-products meal increased. Costs were (6020, 5330, 4640 and 3950 LE/Mg) at fish fed on diets contain (25, 50, 75 and 100% of poultry by-products meal respectively) compared with those fed on the control diet (6660 LE/Mg). In conclusion, replacing up to 50% of fish meal by poultry by-products meal did not affect growth performance and feed utilization for tilapia. The higher replacing levels (75 or 100%) significantly adverse growth and feed utilization parameters.

Constraints Limiting the Effective Utilization of Low-Cost Fish Processing Technologies among Women in Selected Fishing Communities of Lagos State, Nigeria

Constraints limiting the effective utilization of low-cost fish processing technologies among women in selected fishing communities of Lagos State, Nigeria were examined in this study. Ninety-six fish processors were purposively selected as sample size for this study. Chi-square analysis was used for the hypothesis testing in this study to examine the association between constraints and utilization. The mean age of the respondents was 37.8 years, 49.0% had primary school education and 77.1% got skills from their parents. Majority of the respondents did not utilize galvanized smoking kiln (92.7%) and smoking chokor (69.8%). High cost of processing equipment (2.75), poor electricity supply (2.74), poor awareness creation and capacity building (2.72) and inadequate extension support (2.67) as the major problems limiting the utilization of low-cost fish processing technologies in the study area. Result of chi-square presented reveals that significant relationship existed between constraints and utilization of low-cost fish processing technologies at p<0.05 level of significance. It is therefore recommended that effort should be geared towards awareness creation and public enlightenment to promote adoption of low-cost fish processing technologies in the study areas.

Fish offal based aqua-feed for rearing post-larvae of freshwater prawn, Macrobrachium rosenbergii

Market demand for freshwater prawn (Macrobrachium rosenbergii) is high in Sri Lanka. The national agencies stock 20 days old post-larvae (PL20) of this prawns in minor perennial reservoirs but the yield is low due to high mortality. There is a need to develop a low-cost nursing strategy for PL20 before stocking. This research was conducted to evaluate the potential for nursing PL20 in backyard nurseries using low-cost fish offal-based aqua-feed. The trial was carried out in a backyard nursery comprising 6 cement tanks (1.73 m3) each. One hundred PL20 were stocked in each tank (stocking density=57 PL20m-2). There were two feeding treatments each with three replicates: (1) fish offal-based aqua feed (Af), and (2) commercial prawn feed (Cf) at a rate of 5% of body weight. Af was made using a 1:1 mixture of rice bran and boiled fish-offal and Cf was purchased from the market. The feeding rate was adjusted for body weight using bi-weekly sampling and the trial was conducted for 96 days. Average Daily Growth (ADG) of PL20 fed with Af on days 16, 30 and 47 were higher than the ADG of PL20 fed with Cf on same days but not significantly different (p>0.05). However, ADG of PL20 that fed on Af on day 85 and 96 were lower than that were fed on Cf on same days but not significantly different (p>0.05). Nevertheless, ADG of the PL20 that fed on Af on day 63 (0.0038±0.0001 g day-1) was significantly lower (p0.05) from WG of PL20 that fed on Af on same days. However, WG of the PL20 that fed on Cf on days 63 and 85 (0.4551 ± 0.0784 and 1.0117 ± 0.0944 g respectively) were significantly different (p0.05) except the values on day 63 in Af (56.67±1.15) and in Cf (50.3±1.0). However, % survival of PL20 that were fed with Af on days 85 and 96 were lower than that of the PL20 that fed on Cf but not significantly different (p>0.05). Fish offal-based aqua-feed can therefore be effectively used for nursing PL20 of M. rosenbergii for 47 days in backyard nurseries.

Comparative Study of Biochemical Properties of Non-Conventional Plant Sources to Prepare Low Cost Fish Feed

4 Abstract: Biochemical analysis of non-conventional plant sources, Bermuda Grass, Nursery Grass (sages), Typha and Maize Spike (without grains) was done to determine the nutritional value to replace conventional sources such as rice bran, wheat bran and rice polish to prepare low cost fish feed. Analysis was carried out in the research lab of Institute of Biochemistry, University of Sindh, Jamshoro. It was observed that Bermuda grass and Nursery grass (sagas) have good protein value as 2.84 and 10.97, respectively. It is also observed that these non-conventional plants are a good source of energy and easily available around the year.

FISH in chips: turning microfluidic fluorescence in situ hybridization into a quantitative and clinically reliable molecular diagnosis tool.

Microfluidic systems bear promise to provide new powerful tools for the molecular characterization of cancer cells, in particular for the routine detection of multiple cancer biomarkers using a minute amount of the sample. However, taking miniaturized cell-based assays into the clinics requires the implementation and validation of complex biological protocols on chip, as well as the development of disposable microdevices produced at a low cost. Based on a recently developed microfluidic chip made of Cyclic Olefin Copolymer for cell immobilization with minimal dead volume and controlled shear stress, we developed a protocol performed entirely in the liquid phase, allowing the immobilization and fixation of cells and their quantitative characterization by fluorescence in situ hybridization. We demonstrated first in cell lines and then in two clinical case studies the potential of this method to perform quantitative copy number measurement and clinical scoring of the amplification of the ERBB2 gene, a decisive biomarker for the prescription of HER2+ related targeted therapies. This validation was performed in a blind protocol in two clinical case studies, in reference to the gold standard and clinically used method based on glass slides. We obtained a comparable reproducibility and a minor difference in apparent amplification, which can be corrected by internal calibration. The method thus reaches the standard of robustness needed for clinical use. The protocol can be fully automated, and its consumption of samples and DNA probes is reduced as compared to glass slide protocols by a factor of at least 10. The total duration of the assay is divided by two.

Low cost fish feed for aquarium fish: a test case using Colisa fasciata

A comprehensive trial was undertaken to assess the effect of various types of feed on biomass conversion rate as well as on gonad (ovarian) weight in Colisa fasciata, a dual-purpose fish for food and ornamental use. Three groups of juvenile fish (3.0±0.015 g; 10.00±0.75 mm) were fed with three different types of feed: dried earthworm feed, laboratory prepared feed (LPF) and market feed. The LPF made with dried earthworm powder, eggshell powder and plant rhizome (Commelina sp.) dusts proved to be the best and economical feed among the three feed tested. The LPF also increased gonad weight of the cultured fishes indicating a production of more fish offspring’s from a single female fish. The plant rhizome possibly played a role in increasingly appetite among LPF cultured fish, which in turn influenced somatic as well as reproductive growth of those fish.

Smoke curing: A simple method of product development and value addition to low cost fish, Gudusia chapra, Clupeidae, from Hirakud Reservoir, India

Smoke curing: A simple method of product development and value addition to low cost fish, Gudusia chapra, Clupeidae, from Hirakud Reservoir, India

Using Echo Ultrasound from Schooling Fish to Detect and Classify Fish Types

Fish finders have already been widely available in the fishing market for a number of years. However, the sizes of these fish finders are too big and their prices are expensive to suit for the research of robotic fish or mini-submarine. The goal of this research is to propose a low-cost fish detector and classifier which suits for underwater robot or submarine as a proximity sensor. With some pre-condition in hardware and algorithms, the experimental results show that the proposed design has good performance, with a detection rate of 100% and a classification rate of 94%. Both the existing type of fish and the group behavior can be revealed by statistical interpretations such as hovering passion and sparse swimming mode.

Growth and Mortality of Common Octopus (Octopus vulgaris) Fed a Monospecific Fish Diet

The profitability of octopus ongrowing remains limited because low cost artificial diets have not yet been effectively developed. Therefore, alternative, low cost diets are worth exploring. In this study, we have investigated the growth and mortality of octopuses fed strictly on mackerel (Scomber colias), a low cost fish, readily available in the Azores Archipelago. Different weight classes (150–300; 300–600; and 600–1,000 g) were maintained at two stocking densities; 5 versus 12 individuals (ranging between 0.38–2.72 kg m-3). The trial lasted 72 days and was performed in an open system composed of large rectangular tanks. Each individual was tagged, and growth was followed weekly. Mean instantaneous growth rate (G) varied between 0.67 and 1.47 (% increase in body weight day-1), depending on initial body size. Survival was 100% for octopuses held in tanks at low density. On the other hand, increased aggressive interactions in high density tanks resulted in higher mortality rates (MR), especially for the smallest size class (MR = 66.7%). The results of this study suggest that with a monodiet of mackerel, subadult octopuses of 300 g can reach commercial size (750 g) in 2.5 mo. However, high mortality under elevated stocking densities will hinder commercial profitability with such diet. A proposed approach to increase survival would be to periodically supplement the monodiet with crustacean flesh.

Production of lipase and biomass by Staphylococcus simulans grown on sardinella (Sardinella aurita) hydrolysates and peptone

Fish protein hydrolysates from low cost fish species (Sardinella aurita) were prepared and tested as carbon and nitrogen sources for microbial growth and lipase production by Staphylococcus simulans. When cultivated in media containing Whole Sardinella Hydrolysate (WSH) or Meat Sardinella Hydrolysate (MSH), lipase production was significantly low, 5 and 10 U/ml, respectively. However, lipase production was strongly enhanced when partially defatted sardinella hydrolysate was used and highest lipase production was obtained with Partially Defatted Meat sardinella Hydrolysate (PDMSH) (55 U/ml), higher than that obtained with tryptone as nitrogen source. Peptone from sardinella was also prepared and compared with a tryptone from casein and other fish peptones. The results revealed that sardinella peptone is a good substrate for the growth of S. simulans.

Trawls and cooling-water intakes as estuarine fish sampling tools: Comparisons of catch composition, trends in relative abundance, and length selectivity

Fish populations in estuaries are often monitored with traditional sampling gears such as trawls. Trawling is relatively expensive and may be hindered by environmental conditions such as tides and substrates. Power station cooling-water intake screens have been effectively used as estuarine fish sampling devices for many years, but very few quantitative comparisons of intake fish-catch characteristics with samples from other collection methods have been made. Fish collected at the cooling-water intake of a large power station in the lower Forth estuary, UK, were more similar in assemblage composition to fish caught by nearby pelagic trawling than to fish caught by Agassiz (demersal) trawling, mostly because the intake and pelagic-trawl catches were largely composed of clupeids ( Sprattus sprattus and Clupea harengus). The intake catch was typified by pelagic, demersal, and benthic species, however, and was less variable than the catches made by the two trawls. Monthly trends in relative abundance correlated reasonably well between the intake and trawl samples. Fish collected at the intake tended to be significantly smaller than those collected by trawling, which was probably attributable to the intake's smaller mesh size. The study highlighted the utility of a cooling-water intake as an efficient, low-cost fish sampling device, which should be considered as an alternative to trawling as the cost of the latter increases into the future.

Economic profitability of Nile tilapia (Oreochromis niloticus L.) production in Kenya

Economic profitability of Nile tilapia production in Kenya was analysed using a model that simulated individual fish growth and took fish population dynamics in the pond into account. The results suggest that the currently practiced mixed-sex tilapia culture is economically unsustainable. It is suggested that research and extension efforts be geared towards developing monosex Nile tilapia production systems. Nile tilapia culture with African catfish predation should be viewed as an intermediate step towards all-male Nile tilapia culture. This will allow accumulation of both physical and human capital to support all-male tilapia culture. Under all-male culture, economic returns are high enough to justify investment in Nile tilapia culture using borrowed capital. However, the success of monosex culture will depend on the availability and affordability of quality fingerlings and low-cost fish feeds. The results have a wide application in Sub-Saharan Africa where mixed-sex Nile tilapia culture is common.

Chemical composition and binding power of dried pulp wastes produced from the African locust bean (&lt;i&gt;Parkia Biglobosa&lt;/i&gt;) in low cost fish diets.

The chemical compositions of pulp wastes produced from fermented African locust bean before and after fermentation were assessed in order to determine their possible utilization. The fermented bean pulp waste contained protein 11.75 %; ash, 15.86 %; crude fibre, 21.55 %; starch, 32.14 %; dry matter, 93.5% and moisture, 6.5 % while the unfermented pulp contained protein 10.13 %; ash content, 14.14%; crude fibre 22.63%; starch, 28.20%; dry matter, 92.5% and moisture, 7.5%. The unfermented locust bean pulp waste contained some essential amino acids including methionine, lysine, leucine and isoleucine and some non-essential amino acids include histidine, proline, glycine and tyrosine. Concentrations of tannin and oligosaccharides were generally very low. The pulp waste was used wholly and partially to replace corn starch (yellow maize) as a binder in the preparation of the diet of cultured fish ( Clarias gariepinus ). Six diets were formulated using the pulp waste in various proportions. The binding power and the crumbling rate were assessed. The crumbling rate declined with increased inclusion of the pulp. The unfermented locust pulp waste exhibited a stronger binding effect than corn starch after 12 weeks storage. Diets stored in jute bags showed minor quality deterioration due to insect infestation, while diets stored in polythene bags maintained good quality throughout the study period. The use of locust bean waste can thus serve the dual purpose of (a) turning the waste into a useful and value-added farm product and (b) effective substitution for corn starch as a binder in fish feeds. Key Words: Chemical composition, binding power, locust bean, fish diets. Ife Journal of Science Vol.6(1) 2004: 30-34

Mince from low-cost fish species

Fish, which provide a good source of polyunsaturated fatty acids, are becoming increasingly popular in the human diet, and there is a need for new approaches to meeting the growing demand for fish products. The development of value-added products such as protein hydrolysates and surimi-based, extrusion-cooked and fermented fish products from mince recovered from the mechanical deboning of low-cost fish species is reviewed here.

Replacement value of some household wastes as energy substitutes in low-cost diets for rearing catfish in South-Western Nigeria

Trials on growth performance, nutrient utilization and digestibility, as well as carcass composition, were conducted on the clariid catfish, Clarias isheriensis (Sydenham, 1980) to evaluate the replacement value of peels of cassava, yam and plantain, and maize chaff, as substitutes for maize in low-cost fish diets. Triplicate groups of C. isheriensi fingerlings (mean weight, 34·72 g) were fed for 84 days with 37% crude-protein diets containing each of the energy substitutes at 25% inclusion level. The maize chaff diet produced the greatest body weight increases and best growth performance as well as the best feed utilization. This was followed by yam peel, plantain peel and cassava peel diets in decreasing order. Apparent nutrient digestibility coefficients of the experimental diets followed a similar trend. Only the maize chaff diet compared favourably with the control (yellow maize) diet with regard to nutrient utilization and digestibility, which indicated that maize chaff had the greatest potential and desirability as a replacement for yellow maize as the energy source in low-cost diets for C. isheriensis.