Selection of marine species and meals for cephalopod feeding based on their essential mineral composition

A quantitative analysis of the essential mineral content (mg kg^?1 dry weight) was carried out in 31 samples, including molluscs, crustaceans, fish and meals in an attempt to identify those most suitable for formulating cephalopod diets. The mineral ratios (MR: content in the test sample/content in whole Octopus vulgaris) were used as index of nutritional quality. Both crustaceans and oysters presented an optimal profile that covered the macro‐ and microelements composition of O. vulgaris. These samples differed from the rest by their higher Ca, Mg, B, Cu and Zn contents based on a principal component analysis. Fish were deficient in macroelements, such as Na (MR: 70–420 g kg^?1) and Mg (MR: 220–690 g kg^?1), but would be good source of K, Ca and P. Most fish were also deficient in Fe, Zn and Cu, although the copper content would be the most affected (MR: 3–130 g kg^?1). Fish and krill meals showed a high content of Ca and P, although both would be deficient in Na (MR: 440–470 g kg^?1) and Cu (130–540 g kg^?1), along with K, Fe and Zn in krill and Mg and B in fish. Among the plant meals, sunflower and soybean were the most appropriate, presenting higher total content of minerals and MRs above 1000 g kg^?1 for all minerals, except Na, Cu and Zn.     

Lipid classes from marine species and meals intended for cephalopod feeding

In this study, HPTLC was used to make a quantitative analysis of the total lipid content (TL dry weight) and their classes in 39 samples, including molluscs, crustaceans, fish and meals in an attempt to identify those most suitable for formulating diets for cephalopods by reference to an index of nutritional quality (OI_LC: Oser’s index modified for lipid classes). All the crustaceans analysed (<10% TL), fish from artisanal fisheries such as Boops boops, Gadus poutassou, Mugil sp. and Gadus minutus (<10% TL) and the plant meals (TL < 5%) would cause fewer digestive problems than the fish that were a by-catch from fish farms (B. boops or Sparus aurata), pelagic species (Sardina pilchardus or Trachurus trachurus) or krill meal, which are characterised by their high lipid content (20–60% TL). These latter feeds were associated with neutral lipids, mainly triglycerides during the summer. Mytilus galloprovincialis, Carcinus maenas, G. poutassou, Mugil sp., S. pilchardus and G. minutus had a more appropriate lipid content and profile during the winter, when they showed a higher OI_LC due to the greater variety of polar lipid classes they contained. Phospholipids like PS, PI and PE seem to be limiting nutrients in cephalopods because of their high content (78–542, 41–309 and 152–2,114 mg/100 g, respectively) compared with the rest of the samples. None of the meals analysed showed a good nutritional balance per se and should only be used in conjunction with other foods.     

Apparent digestibility and protein quality evaluation of selected feed ingredients in Seriola dumerili

The apparent digestibility coefficients (ADCs) of dry matter, crude protein, crude lipid, and amino acids in fish, krill, squid, meat, defatted krill, soybean, wheat gluten, wheat, camilina, pea, sunflower, and fava bean meals were determined for juvenile Seriola dumerili. The results showed that the ADC of dry matter for yellowtail ranged from 57.7 to 87.2% for animal ingredients and from 42.2 to 82.2% for plant ingredients. An ADC of protein exceeding 90% was observed in fishmeal, while camilina meal and fava bean meal presented the lowest values. Pea meal presented the lowest lipid ADC (83.5%). The availabilities were generally higher in animal ingredients than those in vegetal ones. Except camilina and fava bean meal, the other ingredients appear to be favorable for S. dumerili diets, especially the ones from animal sources. Lower case chemical score values (minimum value from amino acid ratios [AARs]) were obtained in some vegetal ingredients (14–18%), while the highest ones were observed in marine ingredients (69–88%). According to Oser's Index, the most balanced protein for yellowtail with regard to essential amino acids was in krill, defatted krill, and fishmeal (92–96%). So, animal sources are suitable as protein ingredients, but they could be enhanced through some essential amino acid supplementation.     

南极磷虾粉作为鲟鱼饲料蛋白源的营养和氟含量的分析

通过分析商品南极磷虾粉、自制冻干南极磷虾粉和南极磷虾肽粉的主要营养成分和氨基酸含量,以6种鲟鱼肌肉为参比蛋白,利用3种营养评价指标(必需氨基酸指数、氨基酸比值系数分和关联度分析法)评价了这3种磷虾粉作为鲟鱼蛋白质饲料的营养价值;同时对3种南极磷虾粉的氟含量进行了检测分析。结果显示,3种南极磷虾粉平均粗蛋白含量在61.73%～67.13%,粗脂肪含量在3.56%～4.56%,灰分含量在15.56%～17.15%,达到了一级品甚至是特级品的指标。总氨基酸含量达51.46%～58.75%,10种必需氨基酸含量为23.69%～28.51%,三者必需氨基酸总量与粗蛋白的百分比为45.09%～47.94%;呈味氨基酸总量为18.60%～21.19%,占总氨基酸的比例达到了36.07%～36.17%。从必需氨基酸指数方面看,3种南极磷虾粉都为优质的蛋白源。同时从氨基酸比值系数分和关联度分析法,3种南极磷虾粉对于鲟鱼的必需氨基酸平衡性较好,相关系数和鱼粉相差不大,且要高于豆粕。氟含量方面,自制的冷冻冻干南极磷虾粉氟含量最高(2 382.83±112.43 mg.kg-1),其次为商品南极磷虾粉(1 122.73±62.82 mg.kg-1),而经过酶解后南极磷虾肽粉的氟含量(65.19±5.08 mg.kg-1)则显著下降,低于欧盟标准(350 mg.kg-1)。综合来看,3种南极磷虾粉氨基酸平衡性较好,营养价值较高,氟含量可通过一定方法降低,南极磷虾是一种具有较大开发利用前景的优质资源。     

Nutrient evaluation of rotifers and zooplankton: feed for marine fish larvae

The objective of this study was to examine the biochemical composition of intensively reared rotifers after enrichment with three commonly used enrichment media, Multigain, Ori‐Green and DHA‐enriched freshwater algae Chlorella, using standard enrichment protocols at a local cod larvae producer and compare it with that of natural zooplankton from Lofilab AS, a cod larvae producer using semi‐intensive rearing techniques. Unenriched rotifers were analysed to examine whether the enrichment procedures were successful in increasing the content of essential nutrients to level requirements for marine fish larvae. Neither total lipids nor proteins were affected by enrichment. Unenriched rotifers were significantly lower in highly unsaturated fatty acids (HUFAs) and significantly higher in linoleic acid (LA, C18:2, n‐6), than were zooplankton. Enrichment with Chlorella and Multigain increased the HUFAs significantly, while they were slightly reduced after enrichment with Ori‐Green. Total amino acids and mineral content were unaffected by enrichment. Zooplankton was rich in taurine and selenium, whereas rotifers were devoid of it, both prior to and after enrichment. Using zooplankton as a reference for the nutritional requirements of marine fish larvae, results from this study demonstrate that enrichment media currently in use are not effective for enhancing the nutritional quality of rotifers.     

Effect of different feed formulations on feed efficiency, gonad yield and gonad quality in the purple sea urchin Heliocidaris erythrogramma

The nutritive values of three pelleted prepared diets, based on animal (AP), vegetable (VP) and yeast protein (YP) were studied for the sea urchin Heliocidaris erythrogramma (Val.). Fresh macroalga Ulva australis was used as a natural control diet. Triplicate groups of five animals were fed one of the four diets ad libitum every second day for 85 days. Sea urchins fed pelleted feeds had significantly higher food consumption rates (dry basis) and significantly lower total and protein absorption efficiencies compared with the algal diet. The gonad yield and gonad production efficiency in sea urchins fed the natural diet were significantly higher compared with initial group (gonad yield only) and urchins fed animal and vegetable diets, but did not differ significantly from those of the animals fed the yeast diet. Percent protein and lipid in the gonads were not affected by the dietary source. The taste and smell of gonads were generally better in sea urchins collected from the wild or fed yeast and natural diets than in sea urchins fed animal and vegetable diets. The animal protein diet was the most stable in seawater while the yeast protein diet had the poorest water stability. The results of this study suggest that development of a more stable, single‐cell, protein‐based diet has a potential to promote gonad production of H. erythrogramma.     

锈斑蟳肌肉氨基酸和脂肪酸组成分析及营养品质评价

测定了锈斑蟳(Charybdis feriatus)肌肉的氨基酸含量与脂肪酸组成,对其氨基酸含量和脂肪酸组成进行了分析和评价。结果显示,锈斑蟳肌肉干样中共检测出包括牛磺酸在内的19种氨基酸,组成蛋白质的氨基酸总含量为肌肉干重的75.36%,其中,8种必需氨基酸(EAA)的总量为25.41%,占氨基酸(AA)总量的33.73%,非必需氨基酸(NEAA)总量为40.91%,而必需氨基酸与非必需氨基酸的比值(EAA/NEAA)为62.13%;肌肉中4种鲜味氨基酸的含量为28.84%,占氨基酸总量的38.28%;锈斑蟳肌肉中检测出了12种脂肪酸,其中,饱和脂肪酸(SFA)的含量为38.04%,单不饱和脂肪酸(MUFA)的含量为31.58%,多不饱和脂肪酸(PUFA)的含量为29.80%,多不饱和脂肪酸与饱和脂肪酸比值(PUFA/SFA)为0.78,n-3 PUFA与n-6PUFA的比值达到了17.75,多不饱和脂肪酸中EPA和DHA两者的含量达到了20.24%。结果表明,锈斑蟳肌肉中必需氨基酸、鲜味氨基酸含量与不饱和脂肪酸比例较高,具有较高的营养保健价值。     

Empirical feed formulations for the marine ornamental fish,striped damsel,Dascyllus aruanus (Linné 1758) and their physical,chemical and nutritional evaluation

Formulated feeds containing a common ingredient mixture (CIM) consisting of fishmeal (anchovies), shrimp meal (Acetes), squid meal (Loligo) and soybean meal incorporated in ascending levels to obtain protein levels ranging from 180 to 560 g kg^?1(18.34%, 25.35%, 36.27%, 46.61% and 56.28%) and an energy level of 19 MJ kg^?1 were fed to the marine ornamental fish, striped damsel, Dascyllus aruanus <200 mg and 200–300 mg in size for periods of 35 and 63 days. The <200 mg fish accepted particles <0.5 mm in size and showed maximum growth in terms of absolute growth rate (AGR), relative growth rate (RGR) and specific growth rate (SGR) with the feed containing 380 g kg^?1 CIM having a protein content of 362 g kg^?1. Second‐degree polynomial regression equations fitted confirmed these observations with a predicted requirement of 360 g kg^?1 protein. In fish weighing 200–300 mg, growth was not significantly different (P>0.05) in fish fed with feeds containing 380 and 580 g kg^?1 CIM with 360 and 470 g kg^?1 protein. With these data, the second‐degree polynomial regressions showed that a protein level of 464 g kg^?1 would result in an RGR of 107%. The feeds were well accepted by the damselfish, showing good colour retention and health.The cost of the feeds excluding processing costs ranges from US $ 1.35 to 3.36 kg^?1. This is the first report on the development of formulated feeds for damselfish that would help in rearing and aquarium keeping of damselfish worldwide.     

中华绒螫蟹对11种饲料原料蛋白质和氨基酸的表观消化率

以氧化钇（Y2O3）作为指示剂，按照“70％基础饲料＋30％试验原料”的原则配制饲料，测定了体重（97．34±7．36）g的中华绒螯蟹对不同饲料原料蛋白质和氨基酸的表观消化率。试验选取鱼粉、血粉、肉骨粉、乌贼内脏粉、虾壳粉、啤酒酵母、豆粕、棉籽粕、菜籽粕、花生粕、玉米蛋白粉共11种商品蛋白质饲料原料。试验结果表明，中华绒螯蟹对不同饲料蛋白源的粗蛋白表观消化率为40．62％～89．75％，其中，鱼粉和血粉组的粗蛋白表观消化率分别为86．07％和89．75％，显著高于其他原料组；而菜籽粕（42．41％）和玉米蛋白粉组（40．62％）的粗蛋白消化率则明显低于其他饲料蛋白源（P〈0．05）。其他蛋白源的消化率大小顺序依次为：豆粕（77．94％）〉啤酒酵母（76．90％）〉虾壳粉（74．02％）〉肉骨粉（73．78％）〉棉籽粕（71．63％）〉花生粕（65．90％）〉乌贼内脏粉（63．51％）。在动物性蛋白源中，中华绒螯蟹对血粉和鱼粉的氨基酸消化率较高，二者的总氨基酸消化率均高于90％，试验结果还显示，蟹对乌贼内脏粉的氨基酸消化率最低，仅为63．51％；单细胞蛋白源啤酒酵母的总氨基酸消化率（86．77％）高于其他植物性蛋白源；在植物性蛋白源中，对棉籽粕的总氨基酸消化率最高（85．37％），其次是豆粕（79．41％）。本研究结果对评价不同饲料蛋白源的营养价值，以及开发中华绒螯蟹氨基酸营养平衡的人工配合饲料提供了参考和依据。     

中华绒螯蟹对11种饲料原料蛋白质和氨基酸的表观消化率

以氧化钇(Y2O3)作为指示剂,按照"70%基础饲料+30%试验原料"的原则配制饲料,测定了体重(97.34±7.36) g的中华绒螯蟹对不同饲料原料蛋白质和氨基酸的表观消化率.试验选取鱼粉、血粉、肉骨粉、乌贼内脏粉、虾壳粉、啤酒酵母、豆粕、棉籽粕、菜籽粕、花生粕、玉米蛋白粉共11种商品蛋白质饲料原料.试验结果表明,中华绒螯蟹对不同饲料蛋白源的粗蛋白表观消化率为40.62%～89.75%,其中,鱼粉和血粉组的粗蛋白表观消化率分别为86.07%和89.75%,显著高于其他原料组;而菜籽粕(42.41%)和玉米蛋白粉组(40.62%)的粗蛋白消化率则明显低于其他饲料蛋白源(P＜0.05).其他蛋白源的消化率大小顺序依次为:豆粕(77.94%)＞啤酒酵母(76.90%)＞虾壳粉(74.02%)＞肉骨粉(73.78%)＞棉籽粕(71.63%)＞花生粕(65.90%)＞乌贼内脏粉(63.51%).在动物性蛋白源中,中华绒螯蟹对血粉和鱼粉的氨基酸消化率较高,二者的总氨基酸消化率均高于90%,试验结果还显示,蟹对乌贼内脏粉的氨基酸消化率最低,仅为63.51%;单细胞蛋白源啤酒酵母的总氨基酸消化率(86.77%)高于其他植物性蛋白源;在植物性蛋白源中,对棉籽粕的总氨基酸消化率最高(85.37%),其次是豆粕(79.41%).本研究结果对评价不同饲料蛋白源的营养价值,以及开发中华绒螯蟹氨基酸营养平衡的人工配合饲料提供了参考和依据.     

Trawling for cephalopods off the Portuguese coast—Fleet dynamics and landings composition

Fleet dynamics was addressed for three cephalopod taxa of commercial interest, the squid Loligo vulgaris, the octopuses Octopus vulgaris and Eledone cirrhosa, and the cuttlefish Sepia officinalis, for 48 trawlers of the fish trawling fleet. Landing profiles (LP) were identified based on the species composition of the landings using hierarchical cluster analysis. Four out of a total of 12 different LP were related to cephalopods and other species associated with them.The effects on the landing proportions of a number of variables, year, season and vessel, are analysed for each of the species studied using generalized linear models (GLM). The factor “vessel”, including an ensemble of technical characteristics as well as the abilities of individual skippers, explained most of the model deviance, strongly reinforcing the existence of a fleet component dedicated to catch cephalopods. However, time also explains much of the variation found in the data.Seasonal alternation between landings of octopodidae and cuttlefish was observed within a small group of old trawlers operating mainly off the south coast, following the abundance cycles of these species. For a larger group of more modern trawlers, operating off the western coast, inter-annual shift between octopus and squid was found, together with a well marked seasonal pattern between the catches of cephalopods and horse mackerel.Spatial patterns of activity were identified using vessel monitoring system (VMS) data available for trawlers in Portugal, demonstrating the existence of cephalopod targeting strategies in Portuguese fish trawling activities.     

四种石磺的脂质及脂肪酸组成分析

为比较分析紫色疣石磺、瘤背石磺、里氏拟石磺和平疣桑椹石磺4种石磺科贝类的脂质和脂肪酸组成,实验采用气相色谱/质谱法对4种石磺的脂肪酸组成进行分析研究。结果显示:1 4种石磺科贝类肌肉组织总脂(TL)主要由磷脂(PL)、游离脂肪酸(FFA)、胆固醇(Cho)和甘油三酯(TG)组成;紫色疣石磺肌肉组织中的PL/TL高达73.12%,显著高于其他3种石磺(P0.05);瘤背石磺肌肉组织中的TG/TL达2.75%,显著高于其他3种石磺(P0.05);紫色疣石磺肌肉组织中的FFA/TL高达19.16%,显著高于其他3种石磺(P0.05);2 4种石磺肌肉组织中的脂肪酸组成较为平衡;瘤背石磺和紫色疣石磺肌肉组织中的总饱和脂肪酸(ΣSFA)含量均达35%以上;总单不饱和脂肪酸(ΣMUFA)含量从大到小的顺序依次是瘤背石磺(20.63%)、紫色疣石磺(20.49%)、里氏拟石磺(19.61%)、平疣桑椹石磺(19.42%);平疣桑椹石磺肌肉组织中的总多不饱和脂肪酸含量(ΣPUFA)达34.25%,显著高于其他3种石磺(P0.05)。4种石磺中的C20∶5n3(EPA)含量均大于C22∶6n3(DHA)的含量。研究表明,4种石磺的脂质和脂肪酸组成存在较大差异,可能与其生存环境以及生活习性的差异有关,4种石磺的肌肉组织具有较高的脂类营养价值。其中,紫色疣石磺和瘤背石磺含有丰富的人体必需脂肪酸,且营养均衡,适宜食用;里氏拟石磺具有特殊生理活性的脂肪酸成分含量较高。     

The effects of extrusion and pelleting of feed for trout on the digestibility of protein,amino acids and energy and on feed conversion

One feeding and two digestion experiments were performed in order to study the effect of feed processing by extrusion and pelleting on feed conversion and on the digestibility of energy, protein and amino acids. Feed conversion was 1·24 when trout was reared on an extruded diet as compared with 1·61 when reared on the same but pelleted diet. The specific growth rates of 1·56 and 1·55%, respectively, attained with both diets, were almost identical due to a depression of voluntary intake of the extruded diet. The effect of different daily feed intakes in percentage of body weight (NI, %) on the digestibility of energy (D, %) could be described using the following linear regression equations: D(%) = 78·3 ? 5·9 NI(%) for the pelleted diet and D(%) = 87·5 ? 3·9 NI(%) for the extruded diet. Though conversion of the extruded and pelleted diets differed significantly the digestible energy needed to produce 1 kg of gain was nearly the same, 17 370 kJ and 17 580 kJ respectively, indicating that differences in conversion were due to the digestible energy content. The digestion coefficients of the protein and amino acids were not influenced significantly (p < 0·05) by a change in the feed process, but different digestion coefficients for individual amino acids were observed. The use of digestible carbohydrate for trout nutrition is limited by the incidence of liver degeneration.     

三种大洋性柔鱼类营养成分和品质评价

为了探究阿根廷滑柔鱼、秘鲁茎柔鱼及巴特柔鱼的肌肉和皮营养成分与品质差异,采用国标法对其肌肉和皮的基本营养成分、脂肪酸组成和氨基酸组成进行测定分析,利用质构仪和低场核磁共振仪对其肌肉和皮进行了质构和水分分布分析。结果显示,阿根廷滑柔鱼肌肉的粗脂肪含量为1.23%,显著高于其他两种柔鱼（P<0.05）。除水分含量外,柔鱼肌肉的粗蛋白含量、粗脂肪含量和灰分含量均显著高于柔鱼皮（P<0.05）;柔鱼肌肉及柔鱼皮的不饱和脂肪酸含量均大于61%,阿根廷滑柔鱼肌肉的总不饱和脂肪酸ΣUFA为66.51%,显著高于其他两种柔鱼（P<0.05）;不同部位共检测出17 种氨基酸,其中柔鱼肌肉的必需氨基酸总量分别为5.54、6.68和5.97 g,占氨基酸总量的40%以上。柔鱼肌肉中不易流动水含量显著高于柔鱼皮（P<0.05）,阿根廷滑柔鱼肌肉的不易流动水比例最高,为96.92%。阿根廷滑柔鱼的硬度和弹性均显著高于其他两种柔鱼（P<0.05）,未去皮的柔鱼肌肉的胶粘性和黏附性显著高于去皮柔鱼肌肉（P<0.05）。与其他两种柔鱼相比,阿根廷滑柔鱼肌肉的不饱和脂肪酸含量高、质构特性好、保水能力强。去皮和未去皮的柔鱼肌肉在硬度、内聚性和咀嚼性方面没有显著差异（P＞0.05）,柔鱼皮的营养价值略低于肌肉,但仍具有较高加工利用前景。     

俄罗斯鲟烟熏鱼片营养品质分析及评价

以俄罗斯鲟(Acipenser gueldenstaedtii)为原料,制备并分析了烟熏鱼片(冷熏和热熏鱼片)的主要营养成分和物理特性,并对两者的品质进行了比较。结果表明:(1)两种熏鱼片的一般营养成分含量为:水分含量59.73%~69.44%,粗蛋白43.98%~50.51%,脂肪含量33.50%~36.54%,灰分含量1.68%~2.14%,且两种熏鱼片一般营养成分含量均没有显著性差异;(2)氨基酸和脂肪酸组成与含量上,两种熏鱼片均检测出19种氨基酸,其必需氨基酸和鲜味氨基酸含量分别为23.75%~24.25%和23.41%~23.79%,总体上氨基酸营养价值两者间没有差别,仅EAAI冷熏鲟鱼片的略高于热熏鲟鱼片。在熏鱼片中检测到18种脂肪酸,热熏鲟鱼片的饱和脂肪酸要高于冷熏鲟鱼片,而不饱和脂肪酸则略低于冷熏鲟鱼片,其中DHA含量显著低于冷熏鲟鱼片(P0.05),其它脂肪酸均无显著性差异。(3)在质构特性方面,热熏鲟鱼片的硬度、弹性、内聚性和咀嚼性都要高于冷熏鲟鱼片,表明热熏鱼片更有嚼劲。(4)在颜色上,热熏鱼片的亮度(L)和色度角(H*)值要显著低于冷熏鱼片,而饱和度(C*)显著高于冷熏鲟鱼片,即热熏鲟鱼片的颜色较暗,同时肉质偏红,冷熏鱼片的肉质偏黄,且比热熏鱼片颜色淡。质构特性和颜色的差异主要是由于冷熏和热熏过程中不同的干燥和烟熏温度有关。综合分析表明,烟熏鲟鱼片营养价值较高,综合感官评价好,具有较高的市场开发价值。     

Biological and technical evaluation of the potential of marine and anadromous fish species for cold-water mariculture

Concern about the overexploitation of wild aquatic resources, the slow recovery of the groundfish fisheries and the need to encourage the diversification of the mariculture industry of the province of Quebec (Canada) all provided strong incentive to explore the potential of a wide selection of marine and anadromous fish species for cold‐water mariculture. Starting from a list of over 45 indigenous fish species of potential commercial interest, a biotechnical review was initiated. Technical sheets for each species were produced and aquaculture‐based selection criteria covering three aquaculture approaches of development (complete life cycle, on‐growing and stock enhancement) were examined. Species were ranked according to their degree of suitability for the given biological parameters. The final classification analysis within the complete life cycle production strategy positioned the Atlantic wolffish as the top candidate species (91%) followed by the spotted wolffish and Arctic charr (87%). Growth rate, optimal growth temperature, duration of the weaning period, minimal lethal temperature, larval size and feed requirements were the determining criteria. The on‐growing scenario final results ranked Arctic charr first (84%) followed by Atlantic cod (79%) and Atlantic halibut (74%) mostly owing to their growth rate at low temperature and optimal growth temperature criteria. Stock enhancement programmes should concentrate their efforts on the striped bass (56%), the haddock (54%) and the Atlantic sturgeon (34%) based on their growth rate, fishery status, landing price and the availability of impact studies.     

2种乌贼肌肉的营养成分及品质评价

为了探究2种乌贼肌肉营养成分及品质差异,评价其营养价值,本研究对浙江舟山地区捕获量较大的日本无针乌贼(Sepiella japonica)和金乌贼(Sepia esculenta)的常规营养成分、质构特性、蒸煮损失率、甲醛含量、氨基酸和脂肪酸组成及矿物元素进行了分析。结果显示,日本无针乌贼肌肉的粗蛋白、粗脂肪含量与金乌贼相比无显著差异(P>0.05),水分含量显著低于金乌贼(P<0.05),粗灰分含量显著高于金乌贼(P<0.05)。金乌贼肌肉的硬度、弹性、胶粘性、咀嚼性和内聚性均显著高于日本无针乌贼(P<0.05)。2种乌贼肌肉的甲醛含量分别为0.56和1.18 mg/kg,均符合国家卫生标准。氨基酸测定结果显示,2种乌贼的肌肉中均检测出17种水解氨基酸,第一限制性氨基酸均为色氨酸;其中,必需氨基酸占总氨基酸的比例均高于31%,金乌贼与FAO/WHO推荐的理想蛋白模式更接近,其必需氨基酸指数(EAAI)高达82.99。脂肪酸测定结果显示,2种乌贼的肌肉中均检测出20种脂肪酸;其中,C20:5n-3 (EPA)和C22:6n-3 (DHA)的总含量均高于40%,且日本无针乌贼显著高于金乌贼(P<0.05)。2种乌贼肌肉富含人体所需的多种无机元素,常量元素中K和P含量最高,微量元素中Zn和I含量最高。研究表明,2种乌贼肌肉的营养成分及品质存在一定的差异,但均属于优质的低脂蛋白,具有较好的开发利用价值。本研究为开发利用东海头足类海洋资源提供了一定的依据和参考。     

Marine co‐product meals as a substitute of fishmeal in diets for white shrimp Litopenaeus vannamei improve growth,feed intake and muscle HUFA composition

Total replacement of fishmeal using marine co‐product meals in the diets for white shrimp Litopenaeus vannamei and its effects on growth, feed utilization and muscle HUFA and sterol composition were assessed in a 45‐day feeding trial with juvenile shrimp (0.32 g mean initial weight). Eight dietary treatments were tested: a control diet containing fishmeal (FM), a commercial shrimp diet as external reference and six diets where the FM in the control diet was totally replaced by pen shell scallop viscera (Pinna rugosa), squid viscera (Dosidicus gigas) or whole chub mackerel (Scomber japonicus) meals, produced by two methods: (i) cooking followed by grinding and drying and (ii) grinding followed by drying. Survival in all treatments was above 92%, except in the commercial diet (77%). The growth response, feed utilization and chemical composition of shrimp varied among the treatments and were affected in different ways by the by‐products and the meals preparation process. Growth and feed intake were significantly higher in shrimp fed diets containing cooked‐dried squid and pen shell scallop viscera meals, and whole mackerel meal produced by grinding followed by drying. Muscle fatty acid profiles were improved for human consumption when these ingredients were used, compared with the diets containing FM.     

The importance of live‐feed traps – farming marine fish species

This article analyses the challenges of different live‐feed regimes for the rearing of marine finfish larvae and discusses the potential alternative live feeds to avert a future live‐feed trap. Live feeds are indispensable for the successful rearing of larvae of most marine fish species. Brine shrimps (Artemia) and rotifers comprise the live feeds of choice in marine aquaculture today. However, their nutritional composition is deficient in especially essential fatty acids, and enrichment with fish oil is needed. Fish oil is considered a limited resource owing to its origin in fully exploited wild fish stocks. Moreover, fluctuations of the natural population of Artemia will, most likely, influence future availability and prices. This emphasizes the need for optimal exploitation of available live‐feed resources and development of new sustainable alternatives, such as copepods. An array of solutions to these problems are presented to avoid a future live‐feed trap and to reduce dependence on limited resources that influence future production possibilities, species diversification, price volatility and productivity in the aquaculture sector.     

Apparent digestibility of protein, energy, and amino acids in some selected feed ingredients for pacu Piaractus mesopotamicus

The apparent digestibility coefficients (ADCs) of amino acids (AA), protein, and energy in six feed ingredients (Brazilian fish meal, soybean meal, corn gluten meal, alcoholic yeast, corn, and wheat bran) we evaluated for pacu juveniles. In general, all ingredients showed high digestibility values for all AA, and differences among ADCs of individual amino acid were detected ( P  < 0.01). Corn gluten, soybean, and fish meals had the highest ADCs of AA. The ADCs of protein in fish meal, yeast, and corn gluten meal should not be used as AA digestibility indicators, because those showed differences up to 6.7% between the ADCs of protein and AA. All ingredients had lower ADCs of energy than corn gluten meal ( P  < 0.01). Lysine was the first limiting amino acid in fish meal, corn gluten meal, wheat bran, and corn, and the second limiting amino acid in soybean meal, as methionine was the first limiting amino acid in soybean meal and yeast. However, the soybean meal was the best quality protein source, as it had the highest digestible essential amino acid index. This demonstrated that digestible amino acid values can be used to formulate practical diets for pacu, preventing potential deficiencies or excess that might cause environmental and economic losses.