Harvest of crayfish as an ecosystem service of wetlands compared to production systems with planted forage

ABSTRACT

Crayfish harvest as an ecosystem service of moist-soil wetlands in the Mississippi Alluvial Valley (MAV) was evaluated using estimates of crayfish yield and operational costs to create enterprise budgets. The average daily yield of crayfish was 2.13 lb/acre (95% CI = 1.19–3.00) and yield did not differ between wetlands dominated with Red Swamp Crayfish or White River Crayfish. Four hypothetical scenarios of harvest operations revealed annual costs associated with harvesting crayfish to be $163.89–370.75/acre. Although these costs were lower than estimated costs currently associated with harvesting crayfish from fields with planted forage in Louisiana ($749.96/acre), a three-fold reduction in crayfish yield (lb/trap/day) from moist-soil wetlands resulted in an increase in the break-even selling price from $1.25/lb in Louisiana to $1.70–$3.86/lb in the MAV. Although this enterprise will likely not compete with the Louisiana rice-crayfish industry, harvesting crayfish from moist-soil wetlands may contribute to ecosystem services provided by wetlands and aid in the reduction of the quantity of crayfish products imported into the U.S. market.     

Juvenile Procambarus clarkii farmed using biofloc technology or commercial feed in zero‐water exchange indoor tanks: A comparison of growth performance,enzyme activity and proximate composition

A 60‐day study comparing the growth performance; proximate composition and the digestive, immune and antioxidant enzyme activities of juvenile red swamp crayfish (Procambarus clarkii) reared using biofloc technology (the biofloc group) or a commercial diet (the control group) in zero‐water exchange indoor tanks was performed. A commercial diet was fed to both groups, and the daily feeding amount in the biofloc group was 40% less than that in the control group. Wheat bran and glucose were used in the biofloc group to ensure a C/N ratio >15 and the same feeding energy as that given to the control group. After 60 days of feeding, the final weight, weight gain and specific growth rate in the biofloc group were significantly higher than those in the control group. Furthermore, proximate composition analysis showed that the total hepatopancreatic lipid and ash contents of the biofloc group were significantly higher than those of the control group, and the intestinal and hepatopancreatic pepsin activities in crayfish in the biofloc group were higher than those in crayfish in the control group. Moreover, higher hepatopancreatic lipase and cellulase activities were observed for the biofloc group than for the control group. Biofloc technology promoted the health of the crayfish in terms of their immune and antioxidant enzyme activities. Based on the results of this study, biofloc technology is more effective than traditional commercial diets for the farming of juvenile crayfish.     

Production and Evaluation of Mexican-Style Chorizo Sausage Using Invasive Silver Carp (Hypophthalmichthys molitrix) Meat

In the United States, silver carp (Hypophthalmichthys molitrix) is classified as an invasive fish with no commercial value. The main objective of this study was to develop a Mexican-style fish chorizo sausage with silver carp meat. Four formulations (1) containing vinegar (Wet); (2) Wet plus canola oil (O) and cassava starch/soy protein isolate extenders (E); (3) dry seasoning with no vinegar (Dry); and 4) Dry plus OE were evaluated for physicochemical characteristics (proximate composition, pH value, color, cook loss, and textural hardness) and sensory acceptability using 9-point hedonic and just-about-right scales. The addition of OE did not increase (P > 0.05) physicochemical characteristics nor (P > 0.05) sensory acceptance of the chorizo. In contrast, use of DS increased (P > 0.05) the sensory acceptability. However, panelists indicated a “saltiness” perception in all four formulations. A fifth formulation was processed using DS without salt addition. Sensory acceptability increased for this new formulation (scores between 7, like moderately, and 8, like very much). In conclusion, it is possible to formulate a Mexican-style fish chorizo sausage using silver carp meat with DS and no salt. Fish chorizo has good physicochemical characteristics and sensory acceptance, demonstrating a good alternative use for this otherwise underutilized invasive fish species.     

Enrichment of Food Mixtures with Essential Fatty Acids and Calcium from Nile Tilapia By-Products

ABSTRACT

This work aimed at increasing the content of calcium and the quality of fatty acid composition of food mixtures developed with by-products from Nile tilapia fed with flaxseed. Mixes using cassava flour and by-products were submitted to analyses of proximate composition, fatty acids and minerals quantification, and sensory assessment. The lipid and protein fractions were higher for the mix containing 30% addition of fish meal. There was an incorporation effect of essential fatty acids in the mix of flours containing fish fed with flaxseed. Calcium had the highest concentration among minerals. Sensory acceptance range was 55–65% for formulations with fish by-products.     

Comparison of Proximate Composition and Fatty Acid Profile of On-Growing and Wild Mediterranean Horse Mackerel (Trachurus mediterraneus)

ABSTRACT

On-growing of horse mackerel is not known in the world. Recently, we have initiated on-growing of the Mediterranean horse mackerel in the Black Sea. Therefore, we aim to compare proximate composition and fatty acid profile of on-growing and wild horse mackerels to evaluate the effect on their nutritional value. Captured horse mackerels less than 13 cm were kept on-growing in sea cages and fed sea bass feed for a year in the southern Turkish Black Sea. Results showed seasonal variations in the proximate contents and fatty acid profile of both on-growing and wild fish groups (p < 0.05). Protein contents of the wild horse mackerel group were significantly higher than the on-growing mackerel group, while the opposite situation was observed for lipid contents (p < 0.05). Despite higher eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels (as fatty acid methyl esters %) of wild horse mackerel in comparison with on-growing group, much higher EPA + DHA contents were accounted for in on-growing fish in the edible portion resulting from higher lipid contents of these samples. The results suggest that lower amounts of fish meat, 50–90 g, from on-growing mackerel would cover the daily suggested value of EPA + DHA; this level is calculated as 51–150 g for wild fish meat.     

Physicochemical and Microbiological Assessment of Ready-to-Eat Tuna Döner Kebab During Marination,Cooking, and Different Storage Conditions

ABSTRACT

The aim of this work was to investigate the use of bluefin tuna (Thunnus thynnus) in ready-to-eat döner kebab production and determine the effects of marination, cooking, and storage conditions (4 and ?18°C) on physicochemical and microbiological properties of döner kebab. The raw tuna meat and raw, cooked, and stored döner kebab samples were subjected to moisture, protein, fat, ash, pH, cholesterol, biogenic amines, lipid oxidation, fatty acids profile, microbiological, and sensory analysis. The major fatty acids in tuna döner kebab were palmitic, stearic, oleic, omega-3, and omega-6 fatty acids; unsaturated fatty acids were higher than saturated fatty acids (p < 0.05). Low biogenic amine and cholesterol contents were determined in döner kebab. While cooking affected the proximate composition, microbial load, and the levels of histamine and tyramine (p < 0.05), marination did not have any significant effect. The study results indicated that using tuna meat in döner kebab production could be an alternative approach to provide new seafood products without posing any acceptability problems in terms of quality factors.     

The Effect of Depuration on Metals,Bacteria, and Nutrition in Venus verrucosa from the Aegean Sea: Benefit and Risk for Consumer Health of Warty Venus

ABSTRACT

In this study, the effect of the depuration period on proximate composition, metals, fatty acids, and bacteria in the edible tissue of warty venus (Venus verrucosa) collected from ?zmir Bay in the Aegean Sea was investigated. In addition, benefit and risk for human health associated with the consumption of warty venus were determined by atherogenic index (AI), thrombogenic index (TI), polyene index (PI), fish lipid quality (FLQ), target hazard quotient (THQ), and hazard index (HI). The depuration process did not show a significant (P > .05) effect on proximate composition, except for ash. The depuration process was successful in reducing bacteria growth and the concentrations of all metals, except for copper. Total aerobic mesophilic bacteria count of 1.94 log CFU/g in the fresh samples was uncountable at 24 h of depuration. The concentrations of cadmium, lead, copper, iron, and zinc were below the limit values allowed for safe consumption. The analyzed metals were safe for human consumption based on provisional tolerable weekly intake (PTWI), THQ, and HI. Significant variations were also observed in the fatty acid values depending on the depuration periods (P < .05). The n3/n6 and polyunsaturated/saturated fatty acid ratios were greater than those recommended by the FAO/WHO. Moreover, the AI and TI of samples were under established limits.     

Local and regional macroinvertebrate diversity in the wetlands of a cleared agricultural landscape in south‐western Victoria,Australia

• 1. Seasonal pasture wetlands are a common freshwater habitat in many agricultural landscapes, but their invertebrate diversity has rarely been examined compared with other freshwater habitats. Few studies have examined the role of seasonal wetlands for regional biodiversity or the pattern of change in assemblage composition across landscapes.
• 2. Invertebrates were sampled from 16 naturally occurring seasonal wetlands and three perennial wetlands in south‐western Victoria, Australia. The wetlands were arranged in three clusters, separated by at least 20 km: two clusters each contained one perennial and four seasonal wetlands surrounded by pasture; the remaining cluster consisted of one perennial wetland and four seasonal wetlands on a property that has not been cleared of native vegetation, and four adjacent seasonal pasture wetlands cleared of native vegetation.
• 3. Presence/absence data showed that seasonal wetlands had fewer taxa than perennial wetlands, but both were taxon rich. Turnover of taxa was high at all three scales, i.e. between samples within a wetland, between wetlands, and between wetland clusters, but each cluster did not have a characteristic assemblage composition. Up to two‐thirds of the invertebrate taxa found in perennial wetlands were also found in seasonal wetlands, showing that seasonal pasture wetlands could provide an expanded area of winter–spring habitat for many taxa.
• 4. Seasonal pasture wetlands contribute to biodiversity in highly managed and depauperate agricultural landscapes. There was little regionalization of the fauna, taxon turnover was high and ranges appeared relatively continuous. Biodiversity in pasture wetlands was comparable to perennial non‐pasture wetlands elsewhere, despite being used for grazing livestock. This suggests that pasture wetlands may have substantial conservation value and should be managed to protect them from threatening processes such as drainage.

Copyright © 2005 John Wiley & Sons, Ltd.     

基于景观格局的鄱阳湖生态经济区湿地时空变化

基于eCognition面向对象的最邻近域法,选取最优特征组合,对鄱阳湖生态经济区1995年、2005年和2015年遥感影像进行解译和分类提取;参照《湿地公约》及我国湿地分类,依据鄱阳湖实际情况和现有研究资料,同时考虑遥感影像解译过程中的实操性,将鄱阳湖生态经济区土地类型分为湿地和非湿地两大类,即河流、湖泊、沼泽、库塘、水田和林地、裸地、建设用地、草地共9类。采取动态度、质心模型和景观格局指数对20年间该地区湿地的动态变化特征进行分析,并采用地理探测器研究其变化驱动力。结果表明,对于湿地分类,eCognition面向对象的分类方法对湿地影像的提取效果良好;鄱阳湖生态经济区1995-2015年湿地总体面积减少,总体变化率为-25.88%;其中,减少最多的是天然湿地,共减少20.12万hm²;1995-2015年鄱阳湖生态经济区湿地景观指数表现为各斑块破碎度增加,景观多样性及均匀性呈倒“V”变化趋势。湿地变化的驱动力分析表明,人口密度、年均温及坡向均对湿地变化的空间分异有较强的解释能力,人口密度对湿地变化空间分异的解释能力高于年均温和坡向。研究结果可为鄱阳湖生态经济区...     

Growth,Processing Measurements,Tail Meat Yield,and Tail Meat Proximate Composition of Male and Female Australian Red Claw Crayfish,Cherax quadricarinatus,Stocked into Earthen Ponds

Abstract

Small (0.7 g) juvenile red claw, Cherax quadricarinatus, were stocked in earthen ponds (0.04 ha) in Kentucky and grown for 86 days so that measures of growth, survival, processing characteristics, and proximate composition of tail muscle in male and female Australian red claw crayfish could be obtained. A commercial marine shrimp was fed to all red in two separate feedings, each consisting of one-half of the total daily ration between 0800-0830 and between 1530-1600 hours for the duration of the culture period. Total weight and number of red claw from each pond were recorded at the harvest. Forty red claw from each sex were randomly sampled, chill-killed by lowering the body temperature in an ice-bath, and frozen (-20°C) for processing measurements and proximate composition. Red claw were removed from the freezer, thawed, individually weighed to the nearest 0.01 g, and then were hand-processed so that weights of chelae, tail, and tail muscle were obtained to the nearest 0.01 g. After 87 days, red claw had a final average individual weight of 59.6 g, weight gain of 8,413%, survival of 64.0%, yield of 903 kg/ha, and feed conversion ratio (FCR) of 4.63. When analyzed by sex, males had significantly (P < 0.05) higher final individual weight (71.05 g) compared to females (53.65 g); higher (P < 0.05) chelae weight (13.1 g for males compared to 6.84 g for females); higher tail weight (25.53 g for males compared to 20.38 g for females); higher tail muscle weight (18.99 g for males compared to 14.89 g for females); and higher cephalothorax weight (32.41 g for males compared to 26.44 g for females; Table 2). There were no significant differences (P > 0.05) in the percentage moisture, protein, lipid, fiber, and ash in the tail muscle of male and female red claw when analyzed either on a wet-weight basis and averaged 81.0%, percentage protein averaged 16.46%, percentage lipid averaged 0.16%, fiber averaged 0.1%, and percentage ash averaged 1.42%. Results from the present study indicate that red claw can be grown as a commercial aquaculture species in locations with limited growing seasons, and that male red claw grow larger, have larger chelae, and higher tail muscle weights compared to females so that it might be economically advantageous to stock all-male populations of red claw in ponds to achieve maximum production. Further research on growth and processing yields of red claw should be conducted to assist the industry.     

东北地区湿地遥感监测与景观分析

分析东北地区湿地的时空变迁特点,可为东北地区湿地资源的合理利用、合理分配湿地资源、制定东北地区湿地保护和利用相关政策提供科学依据。以1975年MSS遥感图像、2013年CBERS遥感图像为数据源,借助于地理信息系统软件,采用人机交互目视解译的方法,并根据所建立的遥感解译标志,在遥感图像中解译出东北地区湿地信息;引入马尔科夫转移矩阵、重心迁移、景观格局等多种分析方法,探讨东北地区湿地时空动态变化特点。结果表明:近40年来东北地区湿地面积总体呈减少趋势,其中沼泽湿地面积减少24 769.9 km~2、河流湿地面积减少6 753 km~2、人工湿地面积增加22 017.4 km~2;非湿地与湿地各类型间转化明显,其中,沼泽湿地向非湿地、人工湿地转化显著,非湿地向沼泽湿地、人工湿地转化显著;湿地重心总体向南偏西方向迁移36.5 km,其中,人工湿地重心向北偏东方向迁移354.7 km、沼泽湿地重心向南偏西方向迁移261.4 km。景观格局分析显示,东北地区湿地总体向破碎化、多样化与不规则化发展。     

Growth,antioxidant capacity,intestine histology and lipid metabolism of juvenile red claw crayfish,Cherax quadricarinatus,fed different lipid sources

Five dietary lipid sources (fish oil, soybean oil, palm oil, rapeseed oil and linseed oil) were evaluated in juvenile red claw crayfish, Cherax quadricarinatus, based on the response of growth, antioxidant capacity, intestine histology, whole‐body composition, fatty acid nutrition and lipid metabolism. Crayfish were fed in quadruplicate net cages for 8 weeks. Crayfish fed diets with fish oil, soybean oil and linseed oil obtained significantly higher weight gain and specific growth rate than those fed the other two diets. Survival, condition factor and hepatosomatic index were not significantly affected by lipid sources. Lipid sources also do not affect the whole‐body composition of crayfish. Serum SOD, T‐AOC and GSH‐PX activities of crayfish fed the palm oil and rapeseed oil diets had a significantly lower value than those fed other diets. The minimum concentrations of MDA have been observed in crayfish fed the soybean oil diet. The activity of ACC in the hepatopancreas of crayfish fed the linseed oil diet showed the highest value, and the CPT‐1 activity was not significantly affected by different lipid sources. Crayfish fed the soybean oil diet showed significantly higher TC and TG contents in hepatopancreas than those fed other diets. Crayfish fed linseed oil diet had a significantly higher percentage of EPA, C18:3n?3 and Σn?3 PUFA in muscle than those fed other treatments. Most of the fatty acid compositions in the hepatopancreas had a close correlation to fatty acid compositions in diets. All findings in this study indicate that soybean oil is the advantageous lipid source for juvenile C. quadricarinatus which can reflect in satisfactory growth performance, antioxidant capacity and fatty acid nutrition of edible tissues.     

Comparison of Moist and Dry Cooking on Sensory Quality,Consumer Acceptance and Marketability of Canned Bighead Carp

Abstract

Canned bighead carp has shown potential as a freshwater fish product. Canned products made from bighead carp loins that had been either cooked in steam or a convection oven were evaluated by a consumer panel of 90 individuals. The consumers were not told the identity of the fish under consideration. Acceptability was estimated by use of hedonic scales for sensory attributes, open-ended questions about how the products compared to similar canned fish products, and the just right scale for attribute direction for change. Willingness to pay compared to similar products also was determined for each product. Both carp products were light in color and contained less than 1% crude lipids. Acceptability of both products was good with the steam-cooked carp products being slightly more preferred in most categories. For the sensory attribute, “overall liking,” 54% of panelists rated the steam-cooked product as either like very much or like moderately. Likewise, over 60% of panelists indicated that either carp product was better than or equal to canned tuna and that they would be willing to pay as much for either product as tuna.     

Biochemical changes during vitellogenesis in the red claw crayfish,Cherax quadricarinatus (von Martens)

Redclaw crayfish (Cherax quadricarinatus) females at different stages of vitellogenesis were sampled to investigate variations in soluble protein, lipid and water content and in the amino acid and fatty acid composition of the hepatopancreas and ovaries. During vitellogenesis, the changes in the content of soluble proteins and lipids in the hepatopancreas and ovaries were dependent on both diet and the reserves from the hepatopancreas. However, in comparison to the ovary, the fluctuation of the amino acid composition in the hepatopancreas suggested that the protein resources mobilized from this organ was compensating for those gained from feeding. Changes in the fatty acid composition of the hepatopancreas showed limited compensatory function as for the quick accumulation of lipids in the ovaries. The proportional amounts of saturated fatty acids/mono‐unsaturated fatty acids/poly‐unsaturated fatty acids (PUFA) and the predominant fatty acids in both tissues indicated that the mobilization and utilization of fatty acids in freshwater species are different from that in marine species. Based on the redclaw's feeding habits, the commercial pellets used in this study may not be optimal, and a diet with less PUFA may suffice for its vitellogenesis and reduce the feeding costs.     

湖北地区温棚养殖与稻田养殖克氏原螯虾生长特性研究

2018年12月—2019年3月间,定期从温棚养殖和稻田养殖的克氏原螯虾中采集599尾样本,测量克氏原螯虾的体质量(y)、全长(x1)、头胸甲长(x2)、头胸甲宽(x3)、腹节总长(x4)、第一腹节长(x5)、第一腹节宽(x6)、尾节长(x7)、第六腹节长(x8)、第六腹节宽(x9)和螯长(x10),探明温棚养殖幼虾与...     

中华绒螯蟹池塘套养与温室养殖的中华鳖雄体生物学指数和营养成分比较

分别取中华绒螯蟹(Eriocheir sinensis)池塘套养和温室养殖中华鳖(Trionyx sinensis)雄体(分别简称为"套养鳖"和"温室鳖")各5只,解剖取四肢肌肉、裙边和肝脏,分析和比较两种鳖的生物学指数,可食组织常规营养成分、氨基酸含量和脂肪酸组成的差异。结果显示:(1)温室鳖裙边指数(SI)和肝体比(HSI)均显著高于套养鳖(P0.05)。(2)套养鳖肌肉灰分和裙边水分含量均显著高于温室鳖,而裙边蛋白含量则以温室鳖较高(P0.01),套养鳖和温室鳖其余常规营养成分均无显著差异(P0.05)。(3)温室鳖肌肉和裙边中的大部分氨基酸、总必需氨基酸(∑EAA)和总氨基酸(TAA)含量显著高于套养鳖,半胱氨酸含量及EAA/TAA以套养鳖较高(P0.05);套养鳖和温室鳖肌肉和裙边中的必需氨基酸评分(EAAS)较为接近,而EAAS平均值以套养鳖较高。(4)温室鳖肌肉C18:1n9、C18:1n7及单不饱和脂肪酸(∑MUFA)总量显著高于套养鳖,而C22:6n3、总多不饱和脂肪酸(∑PUFA)、∑n-3PUFA、总高度不饱和脂肪酸(∑HUFA)含量及n-3/n-6以套养鳖较高(P0.05);就裙边而言,除温室鳖C17:0和C20:2n6含量显著高于套养鳖外(P0.05),其余脂肪酸含量均无显著差异(P0.05)。综上可见,中华鳖在两种养殖模式下均具有较高的营养价值。     

Seasonal Variations in Proximate and Fatty Acid Composition of Viscera of Sardinella aurita,Sarpa salpa,and Sepia officinalis from Tunisia

Seasonal variations of the proximate composition and fatty acid profiles in viscera from Sardinella aurita, Sarpa salpa, and Sepia officinalis were studied. Significant seasonal variations were observed in the amounts of moisture, lipid, protein, and ash between species. Viscera protein content undergoes large fluctuations. This tendency is different from results observed for the edible parts or for the whole body of many marine species. Ash content also showed significant differences. Lipid contents varied with seasons, in a proportionally inverse manner to water contents. Fatty acid composition showed significant differences from October to December. Interestingly, the highest total omega-3 contents were comparable to many commercial marine fish oils.     

The Influence of Seaweed Composite Flour on the Physicochemical Properties of Muffin

Seaweed has a great potential to be used as an important ingredient in food processing, as it contains a significant content of soluble polysaccharides and has a potential function as a dietary fiber. In this study, seaweed powder (Kappaphycus alvarezii) was incorporated (2–10%) with wheat flour for the production of muffins. The effect of seaweed composite flour on the quality of muffins was investigated using various techniques, such as texture profile and proximate analyses, as well as sensory evaluation. Modification of the muffin formulation to include seaweed powder improved the composition of ash, crude fiber, and moisture content, while the protein and carbohydrate levels decreased, compared to the control sample. An increase in the seaweed component reduced the muffin height, volume, and specific volume. According to the experimental texture profile analysis data, the seaweed affected the textural characteristics of the muffins, increasing the hardness and decreasing the springiness. Sensory evaluation revealed that seaweed powder could be used in the muffin formulation up to 6%, without significantly impacting the color, aroma, and taste attributes relative to the control sample. For overall acceptability, however, the panelists preferred muffins without seaweed powder.     

不同脂肪源对红螯光壳螯虾幼虾生长、消化酶活性及其肌肉生化组成的影响

通过在人工配合饲料中分别添加5%的花生油、猪油、鱼油和豆油作为主要脂肪源,以商业饲料为对照,进行8周饲喂实验,研究不同脂肪源对红螯光壳螯虾(Cherax quadricarinatus)幼虾生长、消化酶活性及其肌肉生化组成的影响。结果显示,不同脂肪源对红螯光壳螯虾幼虾的体长增长率和特定增长率影响不显著(P0.05);但增重率各组间存在显著性差异(P0.05),以豆油组最高,达到2332.93%,花生油组最低,为1839.50%;豆油组肝胰腺指数显著高于其他各组(P0.05),为0.75%。幼虾存活率以豆油组最高(P0.05),达到83.3%,鱼油组较低,仅为56.7%。不同脂肪源饲喂组的肝胰腺胃蛋白酶活力无显著差异(P0.05);脂肪酶活力花生油组显著高于其他实验组(P0.05),为1177.23U/g(prot);淀粉酶活力各组间差异显著(P0.05),由高到低依次为鱼油组、对照组、豆油组、猪油组、花生油组;纤维素酶活力以花生油组较高,为61.14U/(gprot()P0.05)。幼虾腹部肌肉中各种脂肪酸的含量明显受到饲料中脂肪酸种类和含量的影响,饱和脂肪酸含量猪油组显著高于其他组(P0.05);单不饱和脂肪酸以花生油组含量最高,豆油组最低;多不饱和脂肪酸则以豆油组含量最高(P0.05)。在各实验组中,豆油组红螯光壳螯虾幼体具有最高的体质量增长率和存活率,较高的肝胰腺指数和肝胰腺消化酶活力,豆油组幼虾腹部肌肉中多不饱和脂肪酸尤其是亚油酸和亚麻酸含量也较高。因此,以豆油作为主要脂肪源能够满足红螯光壳螯虾幼体的生长需要,获得较好的饲养效果,并降低饲料成本。     

Composition,Lipid Changes,and Sensory Evaluation of Two Sizes of Channel Catfish During Frozen Storage

The effects of size of fish on composition and of time in storage at -18°C on lipid and sensory changes for channel catfish, Ictalurus punctatus, were investigated. Dressed large (1.0 kg) fish (LF) averaged 13.2% fat, while dressed small (0.3 kg) fish (SF) averaged 10.8% fat (P < 0.05). Moisture was lower (P < 0.05) for LF (68.1 vs. 70.8%). Thiobarbituric acid (TBA) values for LF increased during the first ten months and dropped during the 12th month, while TBA values reached their highest level after the 8th month for SF. Free fatty acids did not change for LF but increased (P < 0.05) throughout storage for SF. Lipids for both sizes of fish were 25% saturated, 58% monounsaturated, and 17% polyunsaturated fatty acids. C 14:0, C 18:0, and C 18:3 acids decreased after 12 months of frozen storage. LF were rated higher (P < 0.05) in flavor for the first four months but were not rated significantly different from SF thereafter. These results indicate that although LF contained more fat, they did not oxidize any more than did SF, and both sizes were acceptable to panelists throughout the study. Thus, if channel catfish is handled and stored properly regardless of size, it should be acceptable even after 12 months frozen storage.