Lipid Content Of Fish Research Articles

Evaluation of nutritive value of local fishes in Wani region, Dist. Yavatmal, (Maharashtra state)

In the present investigation an attempt has been made to evaluate nutritive values of local fishes available in Wani area from Nirguda river and Wardha river. The present study was carried out during the period of Nov. 2008 to Oct. 2009. During study the survey, collection, identification and biochemical analysis of local fishes was done.The results of present study showed that all the fishes were rich in protein content, maximum protein content found in Anguilla bengalensis 29.34 % and minimum found in Punctius curmuca 10.34 %. Lipid contents of fishes were low and varied from 1.23 % in Rasbora daniconius to 6.54 % in Heteropneustes fossilis Glycogen content of fishes were negligible and varies from 0.11 % in Ostebrama cotio to 0.090% in Cyprinus carpio.

Spatial and temporal trends of muscle lipid content in Great Lakes fishes: 1970s–2008

An evaluation of spatial and temporal trends in fish lipid content may provide insight into trends of lipophilic contaminant levels, fish population health, and nutritional benefits to fish consumers. Currently, little is known about lipid content in fishes of the Great Lakes, where commercial and recreational fisheries are important. We examined 35+ years of muscle lipid content data for ten Great Lakes fishes from Canadian waters and found lipid content to have significantly (p < 0.05) declined in 2/6 species in Lake Superior, 3/8 species in Lake Huron, 1/8 species in Lake Erie, and 5/10 species in Lake Ontario. Lake Erie showed the least number of declining trends and most increasing trends (2/8 populations, p < 0.1). For most species, recent (2000–2008) muscle lipid values for Lakes Erie and Ontario are significantly higher compared with Lakes Superior and Huron. These observed trends may be linked to a number of environmental changes within the Great Lakes, and the mechanism(s) of decline are likely to be complex.

Effects of dietary soy isoflavones on feed intake, growth performance and digestibility in juvenile Japanese flounder (Paralichthys olivaceus)

An 8-week feeding trial was conducted to investigate the effects of dietary soy isoflavones on feeding intake, growth performance, and digestion of juvenile Japanese flounder (Paralichthys olivaceus). Four isonitrogenous (49% crude protein) and isoenergetic (20.1 MJ kg−1) diets were formulated to contain four graded levels of soy isoflavones, namely, 0, 1, 4 and 8 g soy isoflavones in 1 kg of diet. Each diet was randomly fed to triplicate tanks of fish (Initial average weight: 2.58 g ± 0.01 g), and each tank was stocked with 35 fish. No significant difference was observed among diets with levels of 0, 1 and 4 g kg−1 soy isoflavones in feed intake, weight gain, feed efficiency ratio (FER), proximate composition of fish whole body and apparent digestibility coefficients (ADC) of nutrients and energy (P>0.05). However, high dietary soy isoflavones level (8 g kg−1) significantly depressed weight gain, FER, whole-body crude lipid content of fish and ADC of nutrients (P<0.05). These results indicate that high level of dietary soy isoflavones (above 4 g kg−1) significantly depresses growth responses and FER of Japanese flounder. However, as the content of soy isoflavones in soybean meal is around 1 to 3 g kg−1, the adverse effects might be neglected when soybean products are used as a fish feed ingredient.

Evaluation of Toxicity of Dietary Chelated Copper in Juvenile Olive Flounder, Paralichthys olivaceus, Based on Growth and Tissue Copper Concentration

The present study was conducted to determine the safe and toxic levels of dietary copper in juvenile olive flounder, Paralichthys olivaceus, fed Mintrex® copper, a chelated dietary copper source. Fish averaging 3.8 ± 0.13 g (mean ± SD) were fed 1 of 10 diets (n = 3) containing 7 (Cu0), 10.4 (CuM5), 15.8 (CuM10), 24.9 (CuM20), 43.4 (CuM40), 82.1 (CuM80), 158 (CuM160), 308 (CuM320), 658 (CuM640), and 1267 (CuM1280) mg Cu/kg diet. At the end of 12 wk of feeding trial, weight gain (WG), specific growth rate, and protein efficiency ratio of fish fed CuM5 and CuM10 diets were significantly higher than those fed CuM80, CuM160, CuM320, CuM640, and CuM1280 diets (P &lt; 0.05). Survival of fish fed Cu0, CuM5, CuM10, CuM20, and CuM40 diets was significantly higher than those of fish fed CuM320, CuM640, and CuM1280 diets. Whole‐body lipid content of fish decreased while whole‐body ash increased with dietary copper levels. Whole‐body and tissue copper concentrations increased with dietary copper levels. Although ANOVA test suggested that the toxic level of dietary Cu in juvenile olive flounder, P. olivaceus, could be 320 mg/kg diet, broken‐line analysis of WG indicated a level of 286 mg/kg diet when Mintrex®Cu is used as the dietary copper source.

Resident Fishes Display Elevated Organic Pollutants in Salmon Spawning Streams of the Great Lakes

Pacific salmon (Oncorhynchus spp.) can transport bioaccumulated organic pollutants to stream ecosystems where they spawn and die. We quantified PCBs, DDE, and PBDEs in resident fishes from 13 Great Lakes tributaries to assess biotransport of pollutants associated with introduced Pacific salmon. Resident fishes sampled from salmon spawning reaches had higher mean pollutant concentrations than those from upstream reaches lacking salmon (93.5 and 4.1 μg x kg(-1) [PCB], 24.0 and 3.1 μg x kg(-1) [DDE], 8.5 and 1.0 μg x kg(-1) [PBDE], respectively), but differences varied substantially among lake basins. In Lake Michigan tributaries, PCB concentrations in resident fishes from salmon reaches were over four times higher than those from salmon reaches in Lake Huron and over 30 times higher than those from Lake Superior. Moreover, resident fish pollutant concentrations were better explained by pollutant inputs from salmon (μg x m(-2); R(2) = 0.76 [PCB], 0.64 [DDE], 0.64 [PBDE]) than by land development/agriculture, watershed area, resident fish species, body length, or lipid content. These results suggest that pollutant dispersal to stream ecosystems via biotransport is an often overlooked consequence of salmon stocking and historical food web contamination in the Great Lakes. Our findings have implications for Great Lakes management, including dam removal and wildlife conservation.

Polycyclic aromatic hydrocarbon (PAH) contamination in smoke-cured fish products

In this study, 108 fish samples of smoke cured fish Sardinella aurita (sardines/herrings) collected from 12 major fishing communities along the coastal belt of Ghana were extracted with Soxhlet apparatus using dichloromethane (DCM), and analyzed for sixteen polycyclic aromatic hydrocarbons (PAHs) using the GC/MS (Varian 3800 GC system with 8400 auto-sampler) to determine levels, distribution and the characterization of their sources. The mean total PAHs in the smoked sardines from the various communities ranged from 510.59μg/kg to 1461.79μg/kg for all seasons with a mean value of 716.84μg/kg. The benzo[a]pyrene (BaP) had a maximum mean level of 73.78μg/kg. The unit risk of carcinogenic PAHs for benzo[a]pyrene, chrysene, dibenz[a,h]anthracene, benzo[a]anthracene, benzo[k]fluoranthene, benzo[b]fluoranthene, and indenol[1,2,3-cd]pyrene associated with oral ingestion of smoked sardine was calculated to be 6.1×10−7 for adults and 1.6×10−7 for children. There is a significant correlation between the fish lipid content and the total PAH levels. The average lipid content of the smoked sardine samples collected varied among the various fishing seasons (3 seasons) in Ghana. A significantly high accumulation of PAHs was found in the smoke-cured fish as compared to the non-smoke-cured fish control samples, which showed PAH levels that were below detection (0.10–2.0μg/kg). This study highlights the increased danger of consuming smoke-cured fish in Ghana as some of the PAHs are known to be carcinogenic. These results indicate that there is a need to find alternative ways of curing fish other than the traditional smoking process.

Effects of dietary taurine supplementation to a casein-based diet on growth performance and taurine distribution in two sizes of juvenile turbot (Scophthalmus maximus L.)

Feeding trials were conducted to investigate the effects of dietary taurine on feeding, growth, feed utilization and taurine distribution in tissues of juvenile turbot (Scophthalmus maximus L.) with initial average weight of 6.3±0.01g (Trial 1) and 165.9±5.01g (Trial 2). The basal diet was supplemented with 0.0% (control), 0.5%, 1.0% and 1.5% taurine to formulate four isonitrogenous and isolipidic diets (Diet 1 (0.0%), Diet 2 (0.5%), Diet 3 (1.0%) and Diet 4 (1.5%)). The analyzed taurine concentrations were 0.16%, 0.64%, 1.15%, 1.66%, respectively. Each diet was randomly assigned to triplicate groups of 30 fish (6.3g) in 200L tank and 15 fish (165.9g) in 500L tank. Fish were fed twice daily (06:30 and 18:30) to apparent satiation for 10weeks. With the increase of dietary taurine, growth, feed efficiency ratio (FER) in fish with initial body weight of 6.3g first increased (0.0% to 1.0%) (P=0.000, P=0.000) and thereafter reached a plateau, while growth in fish with initial body weight of 165.9g first increased (0.0% to 0.5%) (P=0.006) and then gradually decreased. Feed intake (FI) in fish with both body weights (6.3g; 165.9g) increased with increasing dietary taurine (P=0.000; P=0.001) and thereafter gradually declined. With increasing dietary taurine, crude protein contents in fish of both body weights increased (P=0.049; P=0.000) and then reached a plateau, while the crude lipid content in fish with 165.9g weight increased with increasing dietary taurine (P=0.000). The contents of taurine in body, muscle, eye, liver and brain of turbot were correlated with consumed taurine, and the correlated coefficients in fish with 6.3g body weight were separately 0.955 (P=0.000), 0.945 (P=0.000), 0.881 (P=0.001), 0.947 (P=0.000) and 0.924 (P=0.002) while those fish with 165.9g body weight were 0.967 (P=0.000), 0.964 (P=0.000), 0.977 (P=0.000), 0.946 (P=0.000) and 0.997 (P=0.000). This result suggested that 1.0% taurine in diet of turbot with 6.3±0.01g weight and 0.5% taurine in diet of turbot with 165.9±5.01g weight are probably optimal.

Evaluation of nutritive value of local fishes in Wani region, Dist. Yavatmal, (Maharashtra)

In the present investigation an attempt has been made to evaluate nutritive values of local fishes available in Wani area from Nirgudariver and Wardhariver. The present study was carried out during the period of Nov. 2008 to Oct. 2009. During study the survey, collection, identification and biochemical analysis of local fishes was done. The results of present study showed that all the fishes were rich in protein content, maximum protein content found in Anguilla bengalensis 29.34 % and minimum found in Punctius curmuca10.34 %. Lipid contents of fishes were low and varied from 1.23 % in Rasboradaniconius to 6.54 % in Heteropneustes fossilis Glycogen content of fishes were negligible and varies from 0.11 % in Ostebramacotioto 0.090% in Cyprinuscarpio.

Rainbow trout performance in food-limited environments: implications for future assessment and management

We evaluated the performance of rainbow trout in food-limited lake and hatchery environments using whole-body water content as a proxy for fish energy reserves and lipid content. Relative abundance of rainbow trout stocked in an oligotrophic lake from 2002 to 2006 decreased by 88% in 145 days. Whole-body water content of rainbow trout increased following stocking in the lake and similar increases in water content were observed in fish from a food-deprived hatchery treatment. Water content in the fed hatchery fish was significantly lower than water content observed in stocked lake fish. Traditional metrics of body condition (i.e., Fulton's K and relative weight) based on length–weight relationships were insufficient to detect the observed changes in whole-body water content for all lake and hatchery treatments. We conclude that depletion of energy reserves contributed to poor survival and low angling returns of stocked rainbow trout in the study lake.

Performance, body compositions, input and output of nitrogen and phosphorus in Siberian sturgeon, Acipenser baerii Brandt, as affected by dietary animal protein blend replacing fishmeal and protein levels

An 8-week growth trial was conducted using a 2 × 3 factorial design to evaluate the effect of substitution of fishmeal (FM) by rendered animal protein blend [APB, comprised of 400 g kg−1 poultry by-product meal, 350 g kg−1 meat and bone meal, 200 g kg−1 hydrolysed feather meal (HFM) and 50 g kg−1 spray-dried blood meal] in diets of Siberian sturgeon, Acipenser baerii Brandt. Two isoenergetic control diets were formulated to contain two different protein levels [high-protein control (400 g kg−1), with 483 g kg−1 of FM] and [low-protein control (360 g kg−1), with 400 g kg−1 of FM]. At each protein level, dietary FM protein was replaced by APB at 75% and 100% levels and supplemented with crystallized essential amino acid under ideal protein concept. The six diets were named as HC, HAPB75, HAPB100, LC, LAPB75 and LAPB100, respectively. No significant differences were found in weight gain rate (WGR) and specific growth rate (SGR), but fish fed with the low-protein diets showed higher feed intake and feed conversion ratio. Plasma growth hormone and insulin-like growth factors I of each group were not significantly different (P > 0.05). The whole-body composition and liver composition were not affected by dietary protein levels, replacement or their interaction. Muscle protein and lipid contents of fish fed with diet LAPB100 were significantly lower than those of HC group. Digestibility of nitrogen (N) and phosphorus (P) were reduced with higher APB inclusion levels, but productive N and P values of all groups were not different. Lower N and P intake induced lower nutrients losses (P < 0.05). The results suggested that dietary protein level could be reduced to 360 g kg−1 from 400 g kg−1 without affecting WGR or SGR and significantly reduced nutrients lose. Furthermore, dietary FM protein can be totally replaced by APB in feed formulation either at 400 g kg−1 or at 360 g kg−1 protein level.

Growth, body composition, intestinal enzyme activities and microflora of juvenile Jian carp (Cyprinus carpiovar. Jian) fed graded levels of dietary valine

This study investigated the effects of valine on growth, intestinal enzyme activities and microflora in juvenile Jian carp (Cyprinus carpio var. Jian). A total of 1200 fish with an average initial weight of 9.67 ± 0.03 g were fed diets containing 5.3 (unsupplemented control), 8.7, 11.8, 14.9, 18.7 and 20.1 g valine kg−1 diet for 60 days. Results indicated that the specific growth rate, feed efficiency, body protein and lipid content of fish were significantly improved by the dietary valine (P < 0.05). The hepatopancreas weight and activities of trypsin, amylase, lipase, chymotrypsin, glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) took the similar trends. Similarly, the optimum levels of dietary valine induced increases in the intestinal length, weight, folds height and activities of alkaline phosphatase, gamma-glutamyl transpeptidase and creatine kinase. In contrast, the trends of muscle GOT activity and plasma ammonia content were opposite. Intestinal Aeromonas, Escherichia coli, Lactobacillus and Bacillus were changed by dietary valine supplementations. The dietary valine requirement for Jian carp (9.67–76.4 g) based on SGR was 13.7 g valine kg−1 diet (4.0 g valine 100 g−1 CP). Together, these results indicated that valine improved fish growth, digestive and absorptive ability.

The effects of varying dietary protein level on growth, feed conversion, body composition and apparent digestibility coefficient of juvenile mangrove red snapper,Lutjanus argentimaculatus(Forsskal 1775)

The effects of several dietary protein levels on the growth, feed conversion, body composition and diet digestibility of juvenile Lutjanus argentimaculatus (body weight 12.3 g) were examined. Seven isolipidic (7.4%) diets were formulated to contain graded levels of protein (28–58%) with dietary energy ranging from 19.7 to 21.5 kJ g−1. Diets were distributed to triplicate groups of fish thrice a day at ration of 2% body weight for 90 days. Growth, feed conversion, protein utilization and digestibility of nutrients increased with increasing dietary protein level up to 43%, after which no significant improvement was observed. Digestibility of dry matter and energy showed a concomitant increase with the reduction in dietary wheat meal, attaining maximal values with high protein diets. No significant differences were detected in moisture, protein, lipid and ash content of whole fish or body organs as dietary protein increased. The mesenteric fat, hepato- and viscerosomatic indices decreased with increasing protein level. The cholesterol, triglycerides and haematocrit values were similar among treatments, except that high levels of plasma lipids were recorded above 43% protein diet. The use of a practical diet containing 43% protein is appropriate for the growth of L. argentimaculatus juveniles under the experimental conditions of the present study.

Growth performance and body composition of kutum fingerlings, Rutilus frisii kutum (Kamenskii 1901),in response to dietary protein levels

A feeding trial was conducted to determine the optimal dietary crude protein requirement for Rutilus frisii kutum fingerlings. Five isoenergetic experimental diets were formulated to contain graded levels of protein (32%, 37%, 42%, 47%, and 52%). Triplicate groups of 80 kutum (average weight 0.5 g) were stocked in 250-L tanks and fed to apparent satiation 3 times a day for 8 weeks. The results indicate that the growth performance and feed utilization of kutum were significantly (P < 0.05) affected by dietary protein level. The second polynomial regression of weight gain against protein level yielded an estimated optimal dietary protein requirement of 41.6%. Weight gain, specific growth rate, and feed efficiency increased with increasing the dietary protein level from 32% to 42%, but decreased significantly (P < 0.05) with further increases in dietary protein. The protein efficiency ratio was inversely correlated with dietary protein level. Feed intake was not affected (P > 0.05) by dietary protein level. No significant difference was found in the whole-body protein, lipid, moisture, or ash contents of fish fed the different dietary protein levels. The results obtained from this study could be beneficial in order to formulate artificial feed for aquaculture of kutum fingerlings.

Growth, Fatty Acids, and Protein Profiles of Carp (Cyprinus carpio L. 1758) Fed Diets with Incremental Levels of Sunflower Seed Meal

This study evaluates the growth performance and nutritive value of carp fed diets containing moderate levels of sunflower seed meal in partial replacement of fishmeal. Four isocaloric and isonitrogenous diets were formulated with 0% (control), 15%, 30%, or 45% sunflower seed meal and fed to triplicate groups of carp (993.82±11.68 g). Growth was assessed using a range of biometric parameters and nutrient utilization was determined by muscle content, fatty acids, and electrophoretic protein profiles of tissues. Condition factor and survival were unaffected by the sunflower seed level butweight gain, protein efficiency rate, and absolute and specific growth ratessignificantly declined as the inclusion level rose. Feed conversion ratio negatively correlated with SGR and reflected feed intake. There were no significant effects on protein, lipid, or pH content of fish, but there were slight alterations in dry matter and ash values. Total saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) dropped as the incorporation of sunflower seed meal increased, contrary to total polyunsaturated fatty acids (PUFA) of both diets and flesh. Minor differences existed in the fractions of sarcoplasmic and myofibrillar proteins, independent of the dietary treatment. In conclusion, sunflower seed inclusion beyond 15% can lead to changes in growth performance and fatty acid composition.

Protective Efficacy of Aqueous Extract of Naringi Crenulata Leaves against Shampoo (Endocrine Disruptor) Induced Toxicity in Labeo Rohita

The protective effect of different concentrations of leaf extracts of N. crenulata was tested against shampoo induced toxicity. 250mg/L/day of leaf extract brought the protein (25.7 ± 0.11), carbohydrate (30.7 ± 0.8) and lipid (5.13 ± 0.4) contents in its normal level in shampoo intoxicated fish. However, in shampoo intoxicated fish lipid content was found highest and decreasing with the increasing concentration of leaf extracts. Length and weight increased with the increase of leaf extract concentration and was observed equal to normal at 250 mg/L (length 6.63 ± 0.2, weight 3.7 ± 0.7). The results also showed that there is positive correlation between length and weight gain, leaf extract concentration and length gain. These results indicate that aqueous leaf extract of N. crenulata acts as an antidote against shampoo toxicity in L. rohita.

배합사료의 수침과 공급량이 넙치(Paralichthys olivaceus)의 성장, 혈액 및 조직 성상에 미치는 영향

Two consecutive feeding trials investigated the effects of feeding rate and pellet expansion by water-soaking on the growth performance, blood components and histology of olive flounder Paralichthys olivaceus. The first two experiments were carried out to determine the effects of pellet expansion and feeding rate. In the first experiment, growth performance, feed utilization and survival of fish were not significantly affected by pellet expansion for six weeks. There were no significant differences in hematocrit, hemoglobin, aspartate aminotransferase, alanine aminotransferase, glucose and total protein of fish fed the expanded pellet. However, whole-body lipid content of fish in the non-expanded group was significantly higher than that in the expanded group. Histological analysis of the anterior intestine revealed that fish in the expanded group had shorter and smaller mucous folds. These results indicate that pellet expansion had no beneficial effect in terms of growth performance, feed utilization and fish health. In the second experiment, weight gain and feed efficiency were significantly increased as feeding rate increased from 0 to 2.5% body weight per day (BW/d), but there were no significant differences in weight gain or feeding efficiency in fish fed the expanded pellet at ratios of 2.5% BW/d and satiation for three weeks. Plasma aspartate aminotransferase activity of fish fed the expanded pellet at a ratio of 2.5% was significantly lower than that of starved fish. Histological analysis of the anterior intestine revealed that fish in the 0% group had shorter mucous folds. Broken-line regression analysis suggested that the optimum juvenile olive flounder feeding rate was 3.5% BW/d during the low temperature season (<TEX>$16-17^{\circ}C$</TEX>).

Effects of dietary histidine levels on growth performance, body composition and intestinal enzymes activities of juvenile Jian carp (Cyprinus carpio var. Jian)

A total of 1200 juvenile Jian carp (Cyprinus carpio var. Jian) (8.76 ± 0.02 g) were fed diets containing graded levels of histidine at 2.3 (unsupplemented control), 4.4, 6.3, 8.6, 10.8 and 12.7 g kg−1 diet for 60 days to investigate the effects of histidine levels on growth performance, body composition, intestinal enzymes activities and microflora. Specific growth rate (SGR), feed efficiency, protein efficiency ratio, protein productive value, body protein content and lipid content of fish were lowest in fish fed the basal diet (P < 0.05). Activities of glutamate-pyruvate transaminase in muscle and hepatopancreas, trypsin, chymotrypsin, amylase, lipase activities in intestine and hepatopancreas, and Na+, K+-ATPase, creatine kinase, alkaline phosphatase, γ-glutamyl transpeptidase activities in three intestinal segments were improved by dietary histidine (P < 0.05), whereas glutamate-oxaloacetate transaminase activities and plasma ammonia content followed an opposite trend. The amounts of Lactobacillus, Escherichia coli and Aeromonas were significantly affected by dietary histidine levels (P < 0.05). These results suggested that histidine could improve growth and enhance intestinal enzymes activities of juvenile Jian carp. The dietary histidine requirement of juvenile Jian carp (8.76–68.02 g) based on SGR was 7.8 g kg−1 diet or 2.38 g 100 g−1 protein by quadratic regression analysis.

Dietary protein requirement of juvenile Asian red-tailed catfish Hemibagrus wyckioides

A feeding trial was conducted to determine the optimum dietary protein requirement of juvenile Asian red-tailed catfish Hemibagrus wyckioides, an omnivorous fish possessing very high culture potential in the Mekong River Basin. Six isocaloric semipurified diets were formulated to contain graded levels of protein (240, 290, 340, 390, 440 and 490 g/kg). Each diet was fed to triplicate groups of fish (initial body weight 1.93 ± 0.02 g) in a recirculating rearing system maintained at 26 ± 1 °C for 8 weeks. Feed intake increased (P<0.05) steadily with increasing dietary protein levels, but no difference (P>0.05) was observed among fish fed diets containing 390, 440 and 490 g/kg protein. Specific growth rate (SGR) of fish fed diet containing 440 g/kg protein was higher (P<0.05) than that of fish fed diets containing 240, 290, 340 and 390 g/kg protein, but not different (P>0.05) from that of fish fed diet containing 490 g/kg protein. Feed conversion ratio decreased (P<0.05) steadily with increasing dietary protein level up to 440 g/kg, whereas protein efficiency ratio in fish fed diet containing 440 g/kg protein was higher (P<0.05) as compared to fish fed diets containing 240, 290 and 340 g/kg protein. The whole-body protein and lipid contents of fish fed diets containing 240 and 290 g/kg protein were lower (P<0.05) than those of fish fed diets containing 340, 390, 440 and 490 g/kg protein. However, allometric analysis showed that the body protein content was solely dependent on fish weight. Broken-line regression analysis showed that the optimum dietary protein requirement for maximum SGR of juvenile H. wyckioides under these experimental conditions was 441.2 g/kg diet with a calculated digestible energy of 15 MJ/kg.

Beneficial effects on meat quality of yellowtail Seriola quinqueradiata induced by diets containing red pepper

The meat quality of farmed yellowtail Seriola quinqueradiata fed on extruded pellets (EP) containing 0.5% (v/v) red pepper (experimental group) was compared with yellowtail of the same age fed on EP (control group). In 1-year-old yellowtail, the crude lipid content of the dorsal muscle of the experimental group tended to be lower than that of the control group. In contrast, there was no difference in the lipid content of the dorsal muscle between the control group and the experimental group in 2-year-old yellowtail. The muscle texture of the experimental group was significantly firmer than that of the control group, with the effect of red pepper unrelated to fish age and lipid content. Color change of red muscle of the experimental group was significantly lower than that of the control group, and the content of thiobarbituric acid-reactive substances in the red muscle was significantly lower in the experimental group than in the control group. These results are the first to demonstrate that the inclusion of red pepper in the diet is able to reduce the loss of muscle texture firmness and to slow down color change in red muscle of yellowtail.

Variations in proximate composition and fatty acid profiles of Baltic sprat (Sprattus sprattus balticus)

The variability of the proximate composition and fatty acid profiles in samples of sprat (Sprattus sprattus balticus) from the southern Baltic Sea were studied in relation to the catch season and location, individual fish size, and sex. Fatty acid profiles depended on such features as fish size and lipid content, which depend on the season of the year in which the fish were caught. No differences in fatty acid profiles were noted between the sexes in the individuals examined. Studies on fish lipids are necessary as fish lipids are important in the prevention of cardiac disease. One of the chief advantages of fish lipids that is relevant to the prevention of cardiac disease is their n−3 to n−6 fatty acid ratio. The most advantageous ratio of these fatty acids was noted in sprat that were the smallest in length.