闽南-台湾浅滩渔场狗母鱼类食性的研究

本文对闽南一台湾浅滩渔场狗母鱼类(多齿蛇鲻、花斑蛇鲻和大头狗母鱼)的食料生物组成、摄食强度的季节变化以及消化器官与食性等方面进行了探讨。结果表明，这三种狗母鱼类都属于游泳动物食性的底层鱼类，而且是同种残食的中级肉食性鱼类，其食料生物组成比较简单，主要摄食鱼类和头足类，还兼食长尾类、短尾类和口足类。被捕食对象的大小，随着捕食对象(多齿蛇鲻或花斑蛇鲻)叉长的增加而增大。狗母鱼类周年均有摄食，多齿蛇鲻和花斑蛇鲻在产卵盛期(3—4月)摄食强度较高。它们的消化器官的形态结构与其肉食性相适应，多齿蛇鲻和花斑蛇鲻的消化器官和食性相近似，比大头狗母鱼的食性较凶猛。     

北部湾鲔(Euthynnus affinis)的摄食习性及其随生长发育的变化

基于2008年9月-2009年9月在北部湾逐月采集的435尾鲔(Euthynnus affinis)生物学数据，对鲔生长、摄食习性及其随生长发育的变化进行了分析。结果显示，北部湾鲔属于广食性鱼类，主要摄食中上层小型鱼类，另外还包括底栖鱼类、甲壳类和头足类等。少鳞犀鳕(Bregmaceros rarisquamosus，45.50%)、青带小公鱼(Stolephorus zollingeri，11.81%)和长颌棱鳀(Theyssa setirostris，5.89%)为鲔优势饵料生物种类，并且其主要饵料生物种类随采样时间的不同而有所差异，如金色小沙丁鱼(Sardinella aurita，1月)、未能鉴定鱼类(4-7月)、长颌棱鳀(8月)、条鲾(Leignathus riviulatus，9月)、青带小公鱼(10月)、少鳞犀鳕(11–翌年3月)。体长小于340 mm的鲔个体随体长的增加其平均摄食饵料生物的个数与质量呈上升趋势；体长在341-520 mm范围内的鲔个体，随着体长的增加其平均摄食饵料生物的个数与质量总体上呈现下降趋势。鲔产卵主要集中在4-8月，根据雌性GSI(性腺成熟度指数)分析，具有两个产卵高峰期(6月、8月)，产卵高峰期和中上层水温的升高有密切关系。鲔的摄食强度在性腺发育过程中波动较大，但在产卵期间，其摄食强度并未明显降低。     

北部湾二长棘犁齿鲷摄食习性和营养级

根据2008年11月—2009年9月期间对南海北部湾拖网渔获物中二长棘犁齿鲷采样所得的生物学资料以及胃含物分析相关数据,应用氮稳定同位素技术对北部湾二长棘犁齿鲷的食物组成、摄食习性、营养级等进行研究。结果发现,二长棘犁齿鲷在北部湾海域广泛摄食,包括中上层鱼类、底栖鱼类、甲壳类和头足类等,鉴定到种的饵料生物有23种,以鱼类为主要饵料生物,占79.74%,主要有麦氏犀鳕、康氏小公鱼、粗纹鲾等,其中麦氏犀鳕所占比例最大,每月均有出现,为58.38%;甲壳类和头足类分别占10.86%、6.97%;根据IRI%分析可知,体长在30~59 mm时主要以小型饵料生物浮游动物为食,而60 mm及以上个体则主要以大型饵料鱼类和底栖无脊椎动物为食,有食性转换现象;饱满指数(RI)有显著的体长变化(P0.05),随性腺发育变化也较明显(P0.05);氮稳定同位素比值δ15N的范围为12.009×10-3~16.007×10-3,营养级随体长和月份的变化均不显著,根据饵料质量百分比及δ15N估算得出北部湾二长棘犁齿鲷营养级平均值分别为3.1和3.7。     

唐山海洋牧场许氏平鮋胃含物分析

2016年7-11月,对唐山海洋牧场海域人工鱼礁内和礁区外许氏平鮋(Sebastes schlegelii)进行采样,共采集191尾,其中鱼礁内159尾,礁区外32尾,对采集的样品胃含物组成进行定量分析和研究,结果表明,许氏平鲉摄食强度以四级为主(40.91%),其次为三级(23.30%),平均摄食强度为2.66。月份不同,胃含物种类不同,7-9月虾类占比100%;11月虾类占比66.99%,鱼类占比33.01%,同时底质不同,胃含物种类也不同,在礁内泥地底质中,虾类占比97.46%;石头地底质中,虾类占比64.42%,鱼类占比33.48%。对不同月份许氏平鮋饵料种类进行聚类分析,结果显示7月与9月饵料相似度高。不同体长组的摄食强度等级频度不同,具体表现为随体长组的增加,摄食强度等级增加,在50~60 mm达到峰值,占比81%。     

浙江南部近海两种石首鱼科鱼类的摄食习性及其食性重叠

对 2020 年 8 月、11 月和 2021 年 1 月在浙江南部近海进行的底拖网调查采集的 287 尾白姑鱼(Pennahia argentata)和 204 尾黑姑鱼(Atrobucca nibe)胃含物样品进行分析, 采用聚类分析等统计方法研究了这两种石首鱼科鱼类(Sciaenidae)的食物组成、摄食习性随体长变化及饵料重叠情况。结果表明, 浙江南部近海白姑鱼摄食饵料生物 48 种, 主要摄食桡足类(Copepoda), 以哲水蚤(Calanus)居多。黑姑鱼摄食饵料生物 43 种, 主要摄食鱼类(Pisces) 和虾类(Decapoda), 优势饵料种类为七星底灯鱼(Benthosema pterotum)。随着体长的增加, 两种石首鱼摄食的主要饵料生物均由浮游动物等小型饵料生物转向鱼类和虾类等大型饵料生物, 摄食强度也随之变化, 白姑鱼的摄食强度随着体长增加而逐渐降低, 而黑姑鱼的摄食强度随着体长增加呈先下降后上升的趋势。两种石首鱼的营养生态位宽度存在较大差异, 其中黑姑鱼的营养生态位宽度(3.06)高于白姑鱼(1.82), 二者间的整体饵料重叠系数为 0.22, 但在部分体长组中存在较大的饵料重叠, 这表明浙江南部近海白姑鱼与黑姑鱼在部分生长阶段有发生食物竞争的可能。     

北部湾春季多齿蛇鲻生物学特征及其年际变化

根据北部湾渔港采样及海上调查生物学测定与数据分析，研究了北部湾多齿蛇鲻(Saurida tumbil)春季生物学特征及其年际变化。结果显示，2008~2018年春季，多齿蛇鲻个体呈小型化趋势，各年度平均体长范围为15.8~16.9 cm，平均体质量范围为48.8~77.5 g，2018年的平均体长和平均体质量比2008年分别降低了6.5%和34.5%。体长–体质量关系式中的异速生长参数b的范围为3.03~3.42，表明春季群体主要呈正异速生长状态(b>3)。性成熟体长年际变化分析表明，北部湾多齿蛇鲻存在性成熟提前的现象，雌性群体50%性成熟体长从2008年(19.0 cm)至2018年(16.6 cm)整体呈减小趋势，10年间减小比例为12.6%，其中，2011~2015年海上采样的样品对比显示，50%性成熟体长减小比例为3.8%。2008~2018年北部湾多齿蛇鲻的肥满度整体呈下降趋势，均值变化范围为1.09~1.29，渔港采样样品和海上采样样品的肥满度年际变化皆呈下降趋势。     

海州湾秋季小眼绿鳍鱼的摄食策略及食物选择性

基于2011年及2013—2015年秋季在海州湾海域进行底拖网调查数据,通过分析733尾小眼绿鳍鱼(Chelidonichthys spinosus)的胃含物样品,对其食物组成、摄食强度、摄食策略以及食物选择性等摄食生态特征进行初步研究。结果表明,小眼绿鳍鱼摄食饵料生物共有80余种,其中优势饵料种类为细螯虾(Leptochela gracilis)、戴氏赤虾(Metapenaeopsis dalei)、疣背宽额虾(Latreutes planirostris)、双斑蟳(Charybdis bimaculata)、细条天竺鲷(Apogon lineatus)等。聚类分析结果显示,小眼绿鳍鱼的食物组成无明显体长变化。不同体长组小眼绿鳍鱼的空胃率差异不显著(P0.05),平均胃饱满指数差异显著(P0.05)。广义加性模型(GAM)分析表明,底层盐度、底层水温和纬度对小眼绿鳍鱼的摄食强度有显著影响(P0.05),而体长、经度和水深的影响则不显著(P0.05)。摄食策略分析表明,小眼绿鳍鱼是以虾类和鱼类为主要饵料类群的广食性鱼类。通过计算食物选择性指数发现,小眼绿鳍鱼喜食饵料与实际摄食的主要饵料种类存在一定差异,表明其摄食既具有较强的主动选择性,同时又受到海州湾饵料丰度和可获得性等因素的影响。     

基于捕食者CPUE权重的浙江南部近海龙头鱼摄食习性分析

根据 2019 年 3 月至 11 月在浙江南部近海进行的 4 个航次底拖网调查所获得的 750 尾龙头鱼(Harpadon nehereus)样本, 采用胃含物分析法, 结合该海域各调查站位龙头鱼的 CPUE, 对其进行了食性分析, 研究了龙头鱼的食物组成、摄食强度及其随季节和体长变化的情况。结果表明, 浙江南部近海龙头鱼摄食的饵料生物有 40 余种, 以鱼类(IRI%=82.29%)和虾类(IRI%=15.77%)为主。优势饵料种类为七星底灯鱼(Benthosema pterotum)、细条天竺鲷 (Apogon lineantus)、龙头鱼和中国毛虾(Acetes chinensis)等。龙头鱼各季节摄食的饵料类群存在一定差异, 但均以鱼类为主。春、秋季摄食的鱼类相对重要性指数百分比(IRI%)超过了 85%, 在夏、冬季, 还摄食了一定比例的虾类。 龙头鱼摄食强度在春季和秋季较高, 冬季最低。不同体长组龙头鱼食物组成差异明显, 随着体长增加, 饵料中鱼类比例逐渐升高, 虾类比例降低。浙江南部近海龙头鱼存在同类相残现象且主要发生在较大体长组内。     

荣成俚岛斑头鱼摄食生态研究

2010年3月至2011年2月逐月采集荣成俚岛近海的743尾斑头鱼(Hexagrammos agrammus),探讨其摄食生态特征。结果表明,斑头鱼为底栖生物食性鱼类,摄食的饵料生物包括11个类群,主要摄食多毛类(Polychaeta),其次是鱼卵、海藻类、海草类、口足类(Stomatopoda)、端足类(Amphipoda)和鱼类等。食物组成随季节和体长而变化:除四季均大量摄食多毛类以外,春季还摄食口足类和虾类,夏季还摄食鱼类和蟹类,秋季还摄食鱼卵和鱼类,冬季摄食鱼卵比例最高;体长80 mm的斑头鱼喜食海草和海藻等植物性饵料,体长80~199 mm的个体喜食多毛类、鱼类和虾蟹类等,体长199 mm的个体主要摄食鱼类、多毛类和鱼卵等。摄食强度也随季节和体长而变化:夏季摄食强度最高,春季和秋季次之,冬季最低(不停食);体长100 mm的个体摄食强度最高,随着体长增加而逐渐下降,体长180 mm以上的个体又随体长和年龄的增大而逐渐升高。对斑头鱼5个饵料生物样品进行了DNA条形码鉴定,其中4个饵料生物样品鉴定到种,1个饵料生物样品鉴定到属。结论认为,斑头鱼的摄食习性会随季节、个体生长和栖息海域饵料生物的种类和丰度的不同而发生变化。     

南沙群岛西南陆架海域主要底层经济鱼类的食性

对多齿蛇鲻（Ｓａｕｒｉｄａｔｕｍｂｉｌ）、蓝圆（Ｄｅｃａｐｔｅｒｕｓｍａｒｕａｄｓｉ）、深水金线鱼（Ｎｅｍｉｐｔｅｒｕｓｂａｔｈｙｂｉｕｓ）和短尾大眼鲷（Ｐｒｉａｃａｎｔｈｕｓｍａｃｒａｃａｎｔｈｕｓ）４种经济鱼类优势种群进行食性分析，根据其胃含物中饵料生物的重量组成和出现频率，可分为３种食性类型。多齿蛇鲻以摄食小型鱼类为主，兼食底栖生物；短尾大眼鲷和蓝圆以摄食浮游动物和小型鱼类（包括幼鱼）为主，兼食底栖生物；深水金线鱼以摄食底栖生物和小型鱼类为主，兼食浮游动物的食性类型。还分析了４种鱼类的食物关系和营养级。     

长江口外海域龙头鱼营养生态学特征

利用2009年9月至2010年8月在东海北部、黄海南部海域获取的龙头鱼(Harpadon nehereus)样品,采用胃含物分析法,对龙头鱼的摄食习性进行了研究。结果表明,龙头鱼摄食饵料种类有39种,鱼类是其主要饵料类群,所占质量百分比为84.13%。优势饵料种类为龙头鱼(Harpadon nehereus)、小黄鱼(Pseudosciaena polyactis)、细条天竺鱼(Apogonichthys lineatus)、皮氏叫姑鱼(Johnius belengerii)、口虾蛄(Oratosquilla oratoria)等。龙头鱼的摄食强度秋季最高,冬季最低;食物组成季节变化明显,春季主要摄食虾类,其他季节则主要以鱼类为食;不同生长发育阶段的食物组成及摄食强度具有显著差异,体长为100 mm和250 mm处存在食性转换现象,并在体长250 mm时表现为由广食性向狭食性转换的特征,摄食选择性增强。龙头鱼营养级为3.80,在东、黄海食物网中处于较高的营养层次。     

东海蓝圆鲹的摄食习性

以2008年5月至2009年2月东海灯光围网采集到的叉长范围为52～276 mm的444尾蓝圆鲹为对象,对其胃含物进行分析,应用K-W非参数检验、卡方检验、聚类分析等方法,对不同季节和发育阶段条件下蓝圆鲹的食性进行了研究。结果表明,蓝圆鲹的摄食种类有80余种,浮游甲壳类(主要包括浮游甲壳类幼体、磷虾和桡足类等)和小型鱼类为其主要食物类群。若按相对重要性指数百分比(IRI%)排序,优势饵料种类最高的是七星底灯鱼(IRI%为40.44%),其次是口虾蛄Alima幼体(IRI%为14.24%)、太平洋磷虾(IRI%为11.26%)等。统计分析检验表明,蓝圆鲹的空胃率和平均胃饱满系数有显著的季节变化和叉长变化(P<0.01),摄食强度春季最高,秋季和夏季相对较高,而冬季最低;叉长50～99 mm和200～299mm的蓝圆鲹的摄食强度较高,其余叉长的强度相对较低。食物组成也随季节和发育阶段的不同而有所变化,在春季主要以七星底灯鱼和口虾蛄Alima幼体为食,夏季主要以甲壳类幼体为食,秋季主要以七星底灯鱼和太平洋磷虾为主食,冬季食物匮乏,小型桡足类丽隆剑水蚤和糠虾类占其食物组成的很大比例。聚类分析的结果表明,蓝圆鲹叉长200 mm是其摄食取向的拐点,小于这个叉长的蓝圆鲹以浮游甲壳类为主,大于这个叉长的以捕食小型鱼类为主,随着叉长的增大,蓝圆鲹更多的以游泳动物为食。根据蓝圆鲹摄食饵料的类群变化,东海蓝圆鲹的营养级为3.55,属于浮游动物和游泳动物混合食性的肉食性鱼类。     

Characterization of Collagen Enzymatic Hydrolysates Derived from Lizardfish (Synodus fuscus) Scales

Acid soluble collagen was extracted from the scales of lizardfish and characterized with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and amino acid analysis. After 8 h of collagen hydrolysis, hydrolysates had an estimated degree of hydrolysis (DH) from 4 ± 0.05 to 25 ± 0.63% (p < 0.05). All hydrolysates had angiotensin converting enzyme inhibitory and antioxidant activity. These activity levels showed little change after treatment with gastrointestinal proteases. Results indicated that the lizardfish by-products may be improved by enzymatic treatment with acid-soluble collagen from lizardfish scales.     

cDNA cloning and complete primary structures of myosin heavy chains from brushtooth lizardfish Saurida undosquamis and wanieso lizardfish S. wanieso fast skeletal muscles

ABSTRACT:   The complete cDNA sequences encoding predominant types of myosin heavy chain (MYH) in the fast skeletal muscle were determined for brushtooth lizardfish Saurida undosquamis and wanieso lizardfish S. wanieso , which are used as materials for preparing high-quality surimi-based products. The cDNA consisted of 5973 and 5987 bp, respectively, and both encompassed an open reading frame encoding a polypeptide of 1936 amino acid residues. Brushtooth and wanieso lizardfish MYH showed the amino acid sequence identity of 92–93% to white croaker MYH, which was higher than that of 90% to walleye pollack MYH. The putative binding sites for ATP, actin, and regulatory and essential light chains in the subfragment-1 region of brushtooth lizardfish MYH exhibited a high identity with white croaker counterparts as well as the sequences of subfragment-2 and light meromyosin. In contrast, phylogenetic tree, constructed by the neighbor-joining method based on mitochondrial 16S rRNA gene, revealed that the two lizardfish species formed a cluster with walleye pollack, which was paraphyletic with white croaker. Therefore, a good reputation for lizardfish and white croaker to have a high thermal-gel forming ability seemed to be reflected by MYH rather than biological similarity as revealed by the mitochondrial 16S rRNA gene.     

Effect of surimi processing on dimethylamine formation in fish meat during frozen storage

Trimethylamine-N-oxide (TMAO) degrades to dimethylamine (DMA) and formaldehyde, which cause a decline in fish quality. Suppression of DMA formation in frozen surimi was investigated using croaker, lizardfish, and walleye pollock. The leaching process in surimi processing was shown to reduce not only the TMAO, iron, and taurine content, but also to reduce unidentified factors that accelerate DMA formation in lizardfish muscle; in contrast, unidentified factors that suppress DMA formation were reduced in croaker and pollock muscle. Sucrose, used as a cryoprotectant, was shown to decrease DMA formation in vitro, likely due to the reduction in freezing-induced concentration of solutes. The effects of pH on DMA formation were different in minced frozen meat among the three species. DMA formation was not observed in croaker when the pH varied between 6 and 8. On the other hand, DMA was elevated in lizardfish under acidic conditions, and DMA formation in pollock was maximal when the pH of the meat was neutral. Thus, the suppression of TMAO degradation by surimi processing results from the removal of TMAO, iron, and reductants from fish meat; sucrose also reduces DMA formation. Furthermore, unidentified factors in croaker, lizardfish, and pollock meat substantially affect DMA formation.     

Age and growth of the lizardfish <Emphasis Type="Italic">Saurida elongata</Emphasis> from the Tsushima/Korea Strait

We studied the age and growth of the lizardfish Saurida elongata using ground thin sections of otoliths (sagittae) from specimens collected in the Tsushima/Korea Strait between May 1999 and June 2001. A total of 695 individuals with fork lengths (FL) ranging from 189 to 478 mm were examined. The frequency of translucent zone occurrence at the outer margin of the otoliths indicated that translucent zones formed once a year between November and February. Most of the males examined were estimated to be 2–7 years old and the females, 3–9 years old. The maximum estimated age of a male specimen was 10 years and that of a female, 11 years. The estimated von Bertalanffy growth curves were FL _t  = 451{1 − exp[−0.172(t + 2.50)]} and FL _t  = 515{1 − exp[−0.151(t + 2.47)]} for males and females, respectively. At all ages, the FL at a specific age for females was greater than that for males, suggesting that females of this species grow faster than males.     

Free amino acid distribution in plasma and liver of juvenile cobia (Rachycentron canadum) fed increased levels of lizardfish silage

Juvenile cobia (Rachycentron canadum) (100 g) were fed four moist diets (447–476 g kg^?1 dry wt) where 0, 130, 260 or 390 g kg^?1 of concentrated lizardfish (Saurida undosquamis) silage replaced fresh lizardfish, respectively. Blood and livers were sampled at 0, 6, 12, 24 and 48 h postfeeding at the end of the 3‐week experiment. At 6 h postfeeding in all groups, maximum concentrations of most plasma essential amino acids were observed, while significantly lower levels of most non‐essential amino acid levels were recorded compared to the other sampled times. At 6 and 12 h after feeding, the concentration of most plasma free amino acid (FAA) increased with an increase in dietary fish silage levels. Most FAA in livers of all groups peaked at 12 and 24 h postfeeding. However, at 48 h postfeeding, concentrations of most plasma FAA were significantly higher in fish fed 0% silage‐based diet than in fish fed the other diets (4999 versus 3390–4339 nmol AA mL^?1 plasma). Growth rates and feed utilization were significantly lower in cobia fed 26% or 39% silage‐based diets than in fish fed 0% or 13% silage‐based diets. Different levels of silage protein thus seemed to have effects on growth and feed utilization efficiency of juvenile cobia. Results from this study support the premise that fish silage can be included until 130 g kg^?1 in cobia diets.     

Diet of late larval Japanese anchovy Engraulis japonicus in the Kii Channel, Japan

The diet of late larval (standard length 17.0–24.9 mm) Japanese anchovy Engraulis japonicus collected from the Kii Channel between April 2007 and March 2008 was analyzed. The main prey items found in the gut were copepods, and the composition of the gut contents changed on a monthly basis. The most important prey items were Calanoida (unidentified) from June to August and in October–November, Oncaea in March, April, and September, and Oithona in December and January. The prey selectivity analysis demonstrated that the selectivity for a particular prey category was not consistent throughout the months. It was considered that late larval anchovy may actually have no preference for a particular prey category. The major size (body width) of the prey items consumed fell within the range of 0.10–0.40 mm throughout almost the whole year. Late larvae tended to select relatively larger prey items from the environment. The relationship between the seasonal variabilities in diet and the fishery catch of anchovy “shirasu” (larvae of anchovy) is also discussed.     

东海北部近海棘头梅童鱼食物组成的季节变化及随发育的变化

根据2006年7月～2008年12月采集于东海北部近海的棘头梅童鱼(Collichthys lucidus)样品,共测定体长在23～157 mm范围内的棘头梅童鱼474 ind,应用卡方检验和聚类分析等方法,对棘头梅童鱼食物组成的季节变化及随个体发育的变化进行了分析。结果显示:东海北部近海棘头梅童鱼的食物种类夏季出现较多,春季出现较少;91～110 mm体长组出现较多,≤50 mm体长组和>130 mm体长组出现较少。食物多样性指数春季较高,秋季较低;≤50 mm体长组较低,>130 mm体长组较高,食物多样性指数随体长的增加而升高。卡方检验显示,棘头梅童鱼主要食物种类宽尾刺糠虾(Acanthomysis latiscauda)、中国毛虾(Aceteschinensis)、七星底灯鱼(Myctophum pterotum)和中华哲水蚤(Calanus sinicus)的出现频率有极显著的季节变化,中华假磷虾(Pseudeuphausia sinica)的出现频率有显著的季节变化;宽尾刺糠虾和七星底灯鱼的出现频率随体长的变化极显著,而中国毛虾、中华假磷虾和中华哲水蚤的出现频率随体长的变化不显著。聚类分析结果表明,棘头梅童鱼春冬季、夏季和秋季三个时期的食物组成差异显著;体长聚类分两组,即体长>70 mm和≤70mm之间食物组成有明显差异。通过分析发现:东海北部近海棘头梅童鱼食物的季节变化与该海域饵料生物的季节变化密切相关;食物组成随发育的变化符合"最佳摄食理论",其饵料生物种类和大小随棘头梅童鱼体长的增加发生了显著的变化。