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Trash Fish (trash + fish)
Selected AbstractsAcute toxicity of water extract of Tephrosia vogelii Hook to species relevant in aquaculture ponds: rotifers, Cyclops, mosquito larvae and fishJOURNAL OF APPLIED ICHTHYOLOGY, Issue 6 2004A. Agbon Summary Rotenone is used to clear ponds of unwanted organisms and trash fish which may predate on fish when the ponds are stocked. Toxicity tests using water extract of the leaves of Tephrosia vogelii Hook, which contains rotenone, were conducted on rotifers (Brachionus species), Cyclops, mosquito larvae (Culex species) and fish (Aphyosemion gardneri nigerianum) in static bioassays. The 48-h LC50s were derived from probit curves using the probit-analysis method, while chi-square was used to test for significant differences between observed mean mortalities and predicted mean mortality values. These showed no significant differences (P > 0.05). The variance ratio of the replicates in each treatment also showed no significant difference (P > 0.05). The 48-h LC50s were found to be 2.89, 1.04, 4.48 and 0.24 mg L,1 for rotifers, Cyclops, mosquito larvae and fish, respectively. The probit mortalities were positively correlated with the log-concentration, except for the rotifers bioassay, which was negative. The fish, A. gardneri nigerianum, was the most sensitive; the mosquito larvae were the least sensitive. [source] Practical diet evaluation with hatchlings of soft-shell turtle, Trionyx sinensis Wiegmann, in the tropicsJOURNAL OF APPLIED ICHTHYOLOGY, Issue 1 2003C.R. Saad Summary An 8-week feeding trial was undertaken to evaluate the growth and survival of soft-shell turtle, Trionyx sinensis, hatchlings fed with trash fish (TF), fish meal (FM), poultry by-product meal (PM) and a 1:1 mixture of FM and PM (MIX). No significant difference (P>0.05) was observed for survival; however, the weight gain and carapace length among different dietary treatments were significantly different (P<0.05). The weight gain and carapace length for hatchlings fed with MIX and PM were highest and lowest (P<0.05), respectively. It is concluded that the inexpensive and readily available poultry by-product can be substituted in part for FM in feed formulation for soft-shell turtle culture. [source] Comparisons of growth and economic performance among monosex and mixed-sex culture of red mud crab (Scylla olivacea Herbst, 1796) in bamboo pens in the tidal flats of mangrove forests, BangladeshAQUACULTURE RESEARCH, Issue 4 2009Mst. Muslima Khatun Abstract An experiment was conducted in a randomized block design to compare growth and economic performance between monosex and mixed-sex culture of red mud crab (Scylla olivacea Herbst, 1796) fed with trash fish at 5,10% body weight per day in the mangrove tidal flat at Burigoaliny Union of Satkhira District, Bangladesh. The experiment had three treatments in triplicate each: (a) all-male culture, (b) all-female culture and (c) mixed-sex culture. Crabs of 80,120 g in size were stocked at a density of 0.5 crab m,2 and cultured for 100 days. Specific growth rates (SGRs) by weight and internal carapace width (ICW) in the all-male culture were significantly higher than those in the all-female culture (P<0.05), while SGRs in the mixed-sex culture showed no significant differences from those in the all-male and all-female culture (P>0.05). No significant differences in final mean body weight, ICW, daily weight gain, survival rate, gross and net yields were found among all the treatments (P>0.05). The area of high water level with mangroves gave significantly better results in terms of feed conversion ratio, survival rate, gross and net yields than the area of low water level (P>0.05). The experiment suggests that the all-female culture in the area of high water level with mangroves could be suitable in developing commercial pen culture of red mud crabs in Bangladesh. [source] Weaning Chinese perch Siniperca chuatsi (Basilewsky) onto artificial diets based upon its specific sensory modality in feedingAQUACULTURE RESEARCH, Issue 2001X F Liang Abstract Chinese perch are one of the most valuable food fish in China, but the sole source of feed for intensive culture is live prey fish. Our previous studies on systematic sensory physiology revealed that this species have a mechanism for this peculiar feeding habit. In the present study, a specific training procedure was designed, and both experimental (initial body weight 171.0 g; 120 days) and commercial (initial body weight 52.4 g; 240 days) net-cage cultures were conducted to investigate the training success, growth performance and survival of the trained yearlings fed with nonlive or Oregon-type moist diet. The training successes of minced prey fish and the Oregon moist diet were 100 and 89.9%, respectively, in experimental culture, and 92.2 and 83.5% in commercial culture. In an experimental trial, the fish fed minced prey fish or the Oregon moist diet attained final body weights of 472.7 g or 344.7 g, although the specific growth rates of these groups were significantly lower than that of the fish fed live prey fish (final body weight 560.0 g). Mortality was not significantly related to dietary treatment. In commercial culture, the final body weights were as follows: 750 g on live prey fish, 705 g on minced prey fish and 651 g on the Oregon moist diet. Feed costs to produce 1 kg fish were estimated to be US$6.59 for live prey fish, US$1.76 for minced prey fish and US$2.07 for the Oregon moist diet. The results of the present study confirmed that sensory modality and associative learning appear to be critical factors in determining food discrimination of Chinese perch, indicating that both minced trash fish and Oregon-type moist diet can be substituted for live prey fish in intensive commercial production. [source] | ||||||||||