以鲥为瘟:古代长江鲥鱼的污名化

鲥鱼在明清一些著作中被称为瘟鱼。历来关于瘟鱼的解释主要围绕鲥鱼本身来阐发,但这些观点不能很好地解释鲥鱼为何会在江西、两湖以及四川一带被称作瘟鱼,而在盛产鲥鱼的江东却没有这种指称。明人的“瘟鱼”观点源自唐人孟诜“发疳、痼”的说法,李时珍所说的蜀地瘟鱼并不是鲥鱼。一些清人认为瘟鱼并非来自鲥鱼本身。《见闻录》中记载了一个鲥鱼被虚构成瘟鱼的故事,揭示出瘟鱼是后人将瘟疫附会到鲥鱼身上的结果。显然,鲥鱼在特定地点被称为瘟鱼,是鲥鱼与地方文化结合的产物。     

Acute Toxicity of Calotropis Procera Latex to Clarias gariepinus Juveniles

Acute toxicity of the latex of C. procera on Clarias gariepinus juveniles was measured over a period of 96-h as a management tool in killing predatory fish in earthen ponds in Nigeria. The latex concentrations of 0.0 mg/l, 10.0 mg/l, 22.0 mg/l, 45.0 mg/l, 100 mg/l, 220 mg/l and 1000 mg/l were used under laboratory conditions in plastic aquaria. The 96 h Lc₅₀ was 64.0 mg/l obtained using graphic and probit methods. The regression equation for the probit curve was y = 2.46x + 0.58 (where probit value = Y, X = log concentration per treatment). Behavioral changes observed during exposure of fish to toxicant include hyperactivity, erratic swimming, imbalance coupled with loss of co-ordination, inclination at the water-air interface, increased opercular beats, clustering and crawling and submergence coupled with paralysis (death). De-pigmentation of the skin increased with increase in latex concentration with a complete bleaching from black/dark brown to pure white occurred at 45.0 and 100.0 mg/l. Histological changes included congestion, haemorrhage, multiple foci of spongiosis of white matter, necrosis and cellular infiltration in the brain tissues. Liver exhibited degeneration, fatty change and infiltration, and generalized haemorrhage. Gill showed congestion of capillaries, keratinization, stunting, necrosis and cell infiltration. The heart-tissues were indifferent to treatments. Histological effects increased in intensity with increase in the concentration of C. procera latex.     

Prioritizing action for recovery and conservation of marine species: a case study based on species of conservation importance around England

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Modelling the distribution of the pan‐continental invasive fish Pseudorasbora parva based on landscape features in the northern Kyushu Island,Japan

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Optimal Conditions to Remove Chemical Hazards in Fish Protein Isolates from Tilapia Frame Using Response Surface Methodology

Response surface methodology (RSM) was employed to maximize the removal of phospholipids (PLs) and other chemical hazards in tilapia protein isolates made from tilapia frame (TF). CaCl₂ and the ratio of water to minced tilapia frame (W:TF) were the significant variables affecting PLs reduction. The optimum condition for maximal PLs reduction (90.0%) was: 10.25 mM CaCl₂ and a W:TF of 7.8:1, while other variables were fixed at 5 mM citric acid, 60 min incubation, pH 11, and centrifugal speed of 8,000 × g. At these conditions, the great reduction of lipids (93.9%), Hg (97.6%), and As (95.5%), as well as 86.1% of protein recovery, were obtained. Protein isolates with significantly reduced chemical hazards and lipids were successfully prepared from tilapia frames using the alkaline extraction assisted with CaCl₂ and citric acid.     

Comparative Effects of Fish and Cow Gelatins and Locust Bean Gum on Chemical,Textural, and Sensory Properties of Yogurt

ABSTRACT

Yogurt is a traditional dairy product widely consumed all over the world. Syneresis, which is a result of lower water holding capacity, is a big concern and an important quality parameter. In this study, the efficiency of locust bean gum and different gelatins (fish skin, fish scale, and bovine skin) in preventing syneresis was investigated. Samples were stored at 4°C for 2 weeks, a typical shelf life of yogurt, and analyzed periodically for quality parameters. Syneresis, viscosity, and water holding capacity of the control and gum added samples were almost identical, while gelatin added samples were generally significantly improved (p < 0.05).     

Evolutionary assembly rules for fish life histories

We revisit the empirical equation of Gislason et al. (2010, Fish and Fisheries 11 :149–158) for predicting natural mortality (M, year^?1) of marine fish. We show it to be equivalent to , where L_∞ (cm) and K (year^?1) are the von Bertalanffy growth equation (VBGE) parameters, and L (cm) is fish length along the growth trajectory within the species. We then interpret K in terms of the VBGE in mass , and show that the previous equation is itself equivalent to a ?? power function rule between M and the mass at first reproduction (W_α); this new ?? power function emerges directly from the life history that maximizes Darwinian fitness in non‐growing populations. We merge this M, W_α power function with other power functions to produce general across‐species scaling rules for yearly reproductive allocation, reproductive effort and age at first reproduction in fish. We then suggest a new way to classify habitats (or lifestyles) as to the life histories they should contain, and we contrast our scheme with the widely used Winemiller–Rose fish lifestyle classification.     

EFFICIENCY OF RESOURCE USE AMONG POND FISH FARMERS IN CENTRAL UGANDA: A STOCHASTIC FRONTIER PRODUCTION FUNCTION APPROACH

This article presents the use of a stochastic frontier production function to examine the efficiency of resource utilization in pond fish farming in Uganda. The study draws on data from a field survey administered to 200 small-scale fish farmers in three major fish farming districts in Central Uganda: Mukono, Mpigi and Wakiso. The districts were part of a large aquaculture development project funded by the United States Agency for International Development-Aquaculture and Fisheries Collaborative Research Support Program. Productive efficiency was analyzed using stochastic frontier analysis with a translog production function while assuming a truncated-normal distribution for the inefficiency term. The output variable was total quantity of fish produced, while input variables were quantity or value of inputs used in the production process, namely labor, pond size, stocking density, capital and feeds. The estimated index of resource-use efficiency revealed that small-scale farmers were inefficient in resource allocation by over-utilizing labor with an estimated allocative efficiency index of ?0.94 and grossly under-utilized pond size, feeds and fingerlings with allocative efficient indices of 1.15, 1.64, 3.71, respectively. The results suggest that there is considerable scope to expand output and also productivity by increasing production efficiency at the relatively inefficient farms and sustaining the efficiency of those operating at or closer to the frontier.     

Digestibility of dietary components and amino acids in plant protein feed ingredients in striped catfish (Pangasianodon hypophthalmus) fingerlings

The apparent digestibility (AD) of dietary components, energy and essential amino acids (EAA) of selected locally available plant protein feed ingredients in striped catfish (Pangasianodon hypophthalmus) fingerlings was studied. The AD of the test ingredients (ADi) differed (P < 0.05) and ranged from 66.2 to 89.6% for ADi_DM, from 63.6 to 91.3% for ADi_CP, from 65.4 to 85.3% for ADi_OM and from 69.8 to 89.3% for ADi_GE. The highest ADi_DM, ADi_OM and ADi_GE in the test ingredients was obtained for broken rice, maize meal and soybean meal, while the lowest values were obtained for duckweed meal. Soybean meal and duckweed meal had the highest ADi_CP, while there were no differences (P > 0.05) between the other test ingredients. The AD of total and individual EAA was higher in soybean meal, duckweed meal and broken rice than in the other test feed ingredients (P < 0.05). The lowest AD of individual EAA was found in maize meal, followed by cassava leaf meal and sweet potato leaf meal (P < 0.05). The low AD of individual plant feed ingredients may limit their potential to be used as replacement for fish meal in the feed.