Effect of Dietary Minerals and Pigment on Somatic Growth of Juvenile Green Sea Urchins, Strongylocentrotus droebachiensis

This study investigated the effects of dietary minerals and pigments in prepared diets on the somatic growth performance of wild and hatchery‐reared juvenile green sea urchins, Strongylocentrotus droebachiensis, by two feeding trials. In the first feeding trial, a modified Bernhart‐Tomerelli salt mix (BT) at 0, 1.5, 3, 6, and 15% dry mass and a Shur‐Gain/Maple Leaf Foods mineral mix at 3 and 6% dry mass were used to test for mineral effects. Pigment effects were tested by incorporating 1.25% Algro? to the prepared diets (i.e., 250 mg of beta‐carotene per kilogram of diet). Sea urchins (13–15 mm of initial test diameter [TD]) collected from the wild were fed the prepared diets over 154 d. The sea urchins that were fed the pigmented diets had significantly greater test growth than those fed the nonpigmented diets, and mineral concentration in the pigmented diets was directly related to juvenile size at the end of the feeding trial. A sample of juveniles from each treatment group was sacrificed to determine test, gonad, and gut yields and ash concentrations. Ash concentrations in the test and gonad were higher for juveniles fed pigmented diets than for those fed nonpigmented diets with similar mineral concentration, suggesting an interaction between minerals and pigments within the juvenile sea urchins. The second feeding trail used two size cohorts of hatchery‐reared juveniles ranging from 1–2 mm and 2–3 mm of initial TD to compare the growth of sea urchins fed either the pigmented diet with 15% BT (i.e., the best diet in the first feeding trial) or kelp, Laminaria longicruris, over 159 d. Growth performance was similar for both cohorts, indicating no size effect, but the juveniles fed the prepared diet were significantly larger at the end of the feeding trial than those fed kelp. This suggests that prepared diets with pigment and high mineral concentration can outperform kelp, and be utilized for juvenile green sea urchins to increase test growth.     

Effect of Protein Source and Concentration on Somatic Growth of Juvenile Green Sea Urchins Strongylocentrotus droebachiensis

Abstract— An important aspect in the development of any aquaculture industry is the maximization of juvenile somatic growth (i.e., body growth) to reduce production time and increase the size of the final product. In this study, green sea urchins Strongylocentrotus clroebachiensis were fed a prepared diet from 4 December 1998 to 10 September 1999 (i.e., 280 d) in a laboratory to investigate the effect of protein source (soybean andlor fish), protein concentration (20,30,40, and 50% dry mass) and juvenile size (4‐8 mm and 12‐20 mm initial test diameter) on somatic growth. A natural diet of Laminwia longicrurus (i.e., kelp) was used as a reference. There was no difference in initial size among the treatments for either the smaller cohort 1 or the larger cohort 2 sea urchins (6.3 mm and 13.8 mm initial average test diameter, respectively) (P > 0.05 for all tests). After 280 d, the sea urchins fed kelp had an average size of 20.7 mm and 24.5 mm (cohort 1 and cohort 2, respectively). The final average sizes of the sea urchins fed the prepared diets, which did not relate to dietary protein concentrations andlor protein source, ranged from 13.2 mm to 16.2 mm (cohort 1) and from 20.4 mm to 22.9 mm (cohort 2), and were significantly smaller than the kelpfed sea urchins (P < 0.05 and P < 0.001, cohort 1 and cohort 2, respectively). All treatments experienced 95% survivorship or greater. Sea urchin size appears to affect growth rate when optimal conditions for growth are available (i.e., diet and water temperature). As water temperatures increased during the summer of 1999, the sea urchins in cohort 1 fed kelp had a significantly higher growth rate (0.069 dd) than the cohort 2 kelpfed sea urchins (0.052 dd) (P < 0.05). However, within each cohort, there were no significant difference in growth rate (P > 0.05) among the sea urchins fed prepared diets, suggesting sea urchins do not require high concentrations of dietary protein for superior growth, and that plant protein can substitute fish protein in sea urchin diets. Furthermore, the sea urchins fed the prepared diets had poorer test quality and larger gonad yields (13‐22%) compared to the kelpfed sea urchins (4.2%) and a wild sample of sea urchins of similar size (4.0%). The results suggest that the sea urchins fed the prepared diets allocated more energy to gonad production, whereas those fed a natural diet allocated more energy toward test production. To address this gap, more research is required to identify the nutritional components required for test growth that were present in kelp, but appeared to be deficient in the prepared diets.     

Optimizing Prepared Feed Ration for Gonad Production of the Green Sea Urchin Strongylocentrotus droebachiensis

Adult green sea urchins Strongylocentrotus droebachiensis were fed three different quantities (0.25, 0.50, 1.00% body weight/d) of a prepared feed during a 12‐wk experiment to determine the effect of food ration on gonad quantity and quality. A diet of kelp, Laminaria longicruris and/or L. digitata, fed at satiation (3% body weight/d) and urchins taken from the wild at the beginning and end of the experiment served as controls. Urchins fed prepared feed or kelp increased their percent gonad yield significantly over the experimental period. Affer 12 wk, individuals fed the prepared diet at 0.50 or 1.00% body weighffd had significantly higher percent gonad yields (mean ± SEM: 23.5 ± 0.6% and 23.4 ± 0.7%, respectively) than urchins fed at 0.25% body weight/d (18.0 ± 1.0%) or control animals given kelp (18.3 ± 0.8%). There was no significant difference in gonad yield between the 0.50 and 1.00% feeding levels. All feeding treatments had significantly higher percent gonad yields than urchins sampled from the wild at the end of the experiment that had recently spawned (2.8 ± 0.5%). There was no significant difference in gonad taste among urchins fed the prepared diet at 0.25% body weight/d, those given kelp, or those collected from the wild at the end of the experiment (good to very good ratings), but all of these treatments had significantly better tasting gonads than urchins given the prepared feed at 0.50 or 1.00% body weight/d (satisfactory ratings). Gonad taste rating of urchins fed a prepared diet was dependent on ration with greater feed amounts leading to worse tasting gonads (linear regression: r²= 0.68, P < 0.01). Gonad color, texture, and firmness did not differ significantly among any of the feed ration treatments or kelp control. Results suggest that the best ration for prepared feed would be 0.50% body weightld since this would optimize gonad yield while minimizing feed costs. Further research on prepared feeds is required to optimize both gonad color and taste.     

Growth of Juvenile Green Sea Urchins,Strongylocentrotus droebachiensis,Fed Formulated Feeds with Varying Protein Levels Compared with a Macroalgal Diet and a Commercial Abalone Feed

The effects of varying protein and carbohydrate levels in prepared diets on the somatic growth of juvenile green sea urchins, Strongylocentrotus droebachiensis, were examined. Ten diets were tested on 600 hatchery reared urchins (mean start weight = 0.11 g) for 6 mo with three replicate groups per diet. Nine of the diets were prepared specifically for urchins and varied in protein (16–40% protein) and carbohydrate (29–49% carbohydrate) levels. The other two diets consisted of a commercially available abalone diet and the kelp, Saccharina latissima. Weight measurements were carried out at 6‐wk intervals, and at the end of the study urchins were individually weighed and a subsample from each treatment was analyzed for gonad weight and color. End weights after 6 mo ranged from 2.56 g for urchins fed the abalone diet to 6.11 g for urchins fed one of the prepared diets. Most of the prepared feeds outperformed kelp, and significant differences in growth were detected between some of the diets. In general, diets with lower protein levels (16–22% protein) and higher carbohydrate levels (>40% carbohydrate) produced the fastest growth. However, further diet refinement and/or use of finishing diets may be necessary to optimize gonad quality.     

The Effect of Astaxanthin in Feed and Environmental Temperature on Carotenoid Concentration in the Gonads of the Green Sea Urchin Strongylocentrotus droebachiensis Müller

The aim of this study was to investigate the long term development of carotenoid concentration in gonads and gonad development of green sea urchins reared at different temperatures and fed formulated feed containing dwerent levels of astaxanthin. Urchins, sampled from a natural population, were reared under two different temperature regimes (7 C and 12 C) and fed formulated feed containing 0, 100 and 500 mg astaxanthin/kg feed, respectively. The study lasted 112 d. Astaxanthin was detected in the groups fed feed containing astaxanthm, but in low quantities. No effect of temperature was observed on the retention of astaxanthin. Echinenone values declined throughout the study, probably due to the lack of suitable metabolic precursor for production of echinenone. Water and lipid concentration in the gonads increased throughout the study indicating the progressions of gametogenesis and the generally improved nutritional status of the animals. No significant difference in gonad index (GI) due to treatment was observed but GI varied between the sexes with male GI increasing significantly faster compared to females.     

中间球海胆精子的超低温保存技术

20 0 0年 10～ 11月 ,对大连龙王塘海区成熟的中间球海胆 (Strongylocentrotusintermedius)精子进行超低温保存研究。结果表明 :不同的抗冻保护剂 ,不同的体积分数 ,不同的冷冻方式 ,精子冻存的效果不同。以自然海水为基础溶液 ,以 12 %的二甲亚砜或 9%的甘油作为抗冻保护剂 ,稀释精液至 8× 10 7～ 11× 10 7个 /ml,距液氮表面 10cm处预冷 8min ,再浸入液氮中保存 ,解冻时直接移出液氮于 17～ 18℃自来水流水解冻 ,精子存活率分别是 95 % ,90 % ;受精率分别为 94 0 % ,86 5 %。     

虾夷马粪海胆壳性状对活体质量的影响效果分析

选择66只13月龄虾夷马粪海胆,测定其体积、壳径、壳高、活体质量,计算相关系数,用通径分析方法计算其他性状对活体质量作为依变量的通径系数、决定系数以及相关指数。试验结果表明,虾夷马粪海胆体积、壳径、壳高、活体质量的相关系数均达到极显著水平(P<0.01),壳径对活体质量的直接影响(0.778)最大,是影响活体质量的主要因素;体积与活体质量的相关程度很大,但是对活体质量的直接影响最小(0.098)。通径系数分析后剔除不显著自变量(体积)后,计算壳径、壳高对活体质量的复相关指数为R2=0.8978,多元回归分析建立了壳径、壳高估计活体质量的回归方程:y=-21.78+1.035x1+0.188x2     

中间球海胆早繁育苗技术的研究

中间球海胆的繁殖期通常为10－11月,通过生物促熟技术使其繁殖期可提前至4－5月。亲胆在18－20℃的条件下投喂自制的促熟饵粒培育,当亲胆积温达到1850℃时,即可进行人工催产,催产诱导率达80％以上。结果表明：促熟水温以18－20℃;促熟饵粒以HD－2＋海带为最佳,海胆幼虫培育成活率为87％,早繁育苗与10月份育苗相比可减少能源消耗,育苗生产成本可降低71％,经济效益显著。     

二价金属离子对光棘球海胆免疫相关酶活力的影响

二价金属离子在海洋无脊椎动物免疫相关酶的活力调控中发挥重要作用。为了解二价金属离子对光棘球海胆免疫相关酶活力的影响,采用生化方法研究了8种二价金属离子在体外不同浓度下对光棘球海胆体腔液中酸/碱性磷酸酶、过氧化氢酶、超氧化物歧化酶、酚氧化酶和髓过氧化物酶活力的影响。结果显示,Cu~(2+)可明显增强碱性磷酸酶、过氧化氢酶、超氧化物歧化酶和酚氧化酶的活力;Mn~(2+)对酸性磷酸酶、碱性磷酸酶、超氧化物歧化酶和髓过氧化物酶有强烈的激活作用;Zn~(2+)对超氧化物歧化酶和酚氧化酶有强烈的抑制作用;Fe~(2+)抑制过氧化氢酶和超氧化物歧化酶的活力;Ca~(2+)对酸性磷酸酶和髓过氧化物酶有抑制作用;Mg~(2+)对碱性磷酸酶有抑制作用;Cd~(2+)对超氧化物歧化酶和酚氧化酶有抑制作用;Pb~(2+)对过氧化氢酶、超氧化物歧化酶和酚氧化酶有抑制作用。试验结果表明,适宜浓度的Mn~(2+)和Cu~(2+)对光棘球海胆的非特异性免疫系统可能有促进作用,而Fe~(2+)、Zn~(2+)、Ca~(2+)、Mg~(2+)、Pb~(2+)和Cd~(2+)可能会削弱光棘球海胆的免疫应答能力。     

筏式养殖中间球海胆生殖腺发育周年变化

1998年 3月～ 1999年 5月间调查了筏式养殖体系中中间球海胆生殖腺发育的周年变化。结果表明 ,海胆的个体大小及性别不同 ,生殖腺成熟期及生殖腺指数变化略有不同。A组 (壳径 3 5～ 5 0cm)海胆的成熟期为 6～ 10月 ,B组 (壳径 5 0～ 6 5cm)为 5～ 10月。壳径大的海胆生殖腺成熟早且成熟期长。雄性较雌性生殖腺发育较快 ,成熟较早 ,成熟期保持时间长。 10月底至 11月初生殖腺指数急剧降低 ,此时为繁殖高峰期。雄性个体的生殖腺指数在 3～10月间略高 ,其余时间无明显性别差异。除排放期和恢复期外 ,A组的生殖腺指数均略低于同期B组     

KCl诱导虾夷马粪海胆幼体变态的研究

研究了不同浓度的KCl对于虾夷马粪海胆幼体变态的诱导作用及对变态后个体生长的影响。试验结果表明,KCl对虾夷马粪海胆是一种极好的变态诱导剂,0.05 mol/L的KCl作用5~10 h诱导效果最佳,在提高变态率的同时,大大地降低了死亡率。     

KC1对中间球海胆幼虫变态的诱导效果

中间球海胆（Strongylocentrotus intermedius)八腕后期幼虫，在KC1添加浓度100mmol/L海水中，分别处理5，10，15min后，均变态为正常稚海胆，中间试验及生产应用结果表明，经KC1处理，幼虫的附着时间缩短了36h，附着率则分别增加了40．4％，27．75％。     

两种海水酸化模式对中间球海胆早期发育及存活的影响

采用二氧化碳法和强酸法模拟海水酸化效应,研究两种海水酸化模式对中间球海胆早期发育及存活的影响。试验结果显示,两种海水酸化模式均能降低中间球海胆胚胎的上浮率和四腕浮游幼体的存活率;显微观察得知,两种海水酸化模式下,中间球海胆四腕浮游幼体均出现对称性缺失和骨针外露现象,且对称性缺失程度随海水pH的降低而升高;扫描电镜观察发现,两种海水酸化模式下,中间球海胆四腕浮游幼体骨针的表面及横截面均有溶蚀痕迹,且溶蚀程度随海水pH的降低而加剧。结果提示,海水酸化可通过降低胚胎上浮率、浮游幼体存活率以及破坏幼体对称性和骨针结构影响中间球海胆的早期发育及存活。     

Food Consumption, Absorption, Assimilation and Growth of the Sea Urchin Strongylocentrotus intermedius Fed a Prepared Feed and the Alga Laminaria japonica

Prepared feeds are standard for developed aquaculture programs. Prepared feeds have been shown to be effective for several species of sea urchins. We investigated the use of prepared feeds for culture of the important commercial species Strongylocentrotus intermedius by comparison with the usual food used, the brown alga Laminaria japonica . The experiment was done in the summer and consisted of two successive 30-d periods. Individuals consumed more of the alga than the prepared feed but the absorption efficiencies were the same. This probably resulted from a higher content of structural carbohydrates in the alga and a higher content of available organic matter in the feed. The amount of organic matter absorbed was the same for both foods. However, the amount of gonad production and the assimilation efficiency was greater for the prepared feed. This indicates the prepared feed is of better nutritional quality. The physiological measurements and production were greater in the first 30-d period when the temperature was < 20 C than in the second when it was > 21 C. This indicates temperature will be an important consideration in aquaculture of S. intermedius .     

不同糖源对拟穴青蟹仔蟹的生长、体成分及消化酶的影响

在水温26~30℃,盐度18~22条件下,初始体质量(0.012±0.000)g的拟穴青蟹仔蟹饲养在底铺1~2 cm细沙、边缘放5 cm^2瓦片的塑料水桶(直径20 cm,水深20 cm)中,投喂以葡萄糖、蔗糖、糊精、木薯淀粉、玉米淀粉、糊化木薯淀粉和糊化玉米淀粉为糖源的7种等氮等能饲料,养殖3周,研究不同糖源对拟穴青蟹仔蟹生长、体组成及消化酶活性的影响。试验结果显示,不同糖源显著影响拟穴青蟹仔蟹的生长性能(P<0.05);质量增加率和特定生长率依次为糊化木薯淀粉>糊化玉米淀粉>木薯淀粉>玉米淀粉>糊精>蔗糖>葡萄糖;葡萄糖试验组的成活率显著低于其他各组(P<0.05)。不同糖源对拟穴青蟹仔蟹体组成中粗蛋白和粗脂肪含量影响显著(P<0.05),对仔蟹的水分和灰分含量影响不显著(P>0.05);不同糖源对3种消化酶活性影响显著(P<0.05)。拟穴青蟹仔蟹对大分子糖源的生物利用度要大于小分子糖源。在本试验的研究条件下,7种常见糖源中糊化木薯淀粉是拟穴青蟹仔蟹的最适糖源。     

四种因子对仿刺参幼参牛长的影响

以益生菌、水温、寡糖和配合饲料为因素,仿刺参幼参的特定生长率为指标,通过L9(34)正交试验方法,研究4种因子对仿刺参幼参生长的影响,获得各因子的最佳组合参数.试验结果显示,4种因子对幼参特定生长率的影响均极显著(P＜0.01),影响因素为益生菌＞水温＞寡糖＞配合饲料.最佳的因素搭配为益生菌5 mL/m3,水温24℃,壳寡糖+褐藻胶寡糖混合0.002 g/L,幼参B型配合饲料.各因素水平对仿刺参幼参特定生长率影响为益生菌5 mL/m3＞15 mL/m3＞10 mL/m3,水温24℃＞17℃＞10℃,壳寡糖+褐藻胶寡糖＞褐藻胶寡糖＞壳寡糖,幼参饲料B型＞幼参饲料加强型＞稚参饲料.     

The Effect of Temperature on Production of Gonads by the Sea Urchin Strongylocentrotus franciscanus Fed Natural and Prepared Diets

Strongylocentrotus franciscanus (248 ± 76 g wet body weight, mean and standard deviation) were maintained in the laboratory at 12.9 and 16.1 C and fed either Nereocystis luetkeana or a prepared feed for 4 mo (July through October). The size and histological condition of the gonads of an initial sample, the experimental animals, and a sample from the commercial fishery were evaluated. The gonad index of experimental S. franciscanus increased from an initial 3.4%± 1.4 to 19.2%± 3.3 (mean and standard deviation) for the four treatments. The feeding rate was greater for individuals fed N. luetkeana and for both foods at the higher temperature. Gonad production was not significantly different among the experimental treatments, indicating the prepared feed was nutritionally superior to the algal diet and an increase in catabolism at the higher temperature balanced the increase in food intake. Histological preparations determined the urchin gonads developed from an initial spent condition to the premature stage for both experimental and fishery samples, indicating neither food or temperature affected gametogenesis.     

植酸酶对鲤鱼生长及磷利用率的影响

选用300尾体重为50 g左右的鲤鱼鱼种,随机分为5组:对照组、Ⅰ组、Ⅱ组、Ⅲ组和Ⅳ组。对照组饲喂基础饲料,Ⅰ组饲喂每千克添加1500 U植酸酶的基础饲料,Ⅱ组饲喂每千克添加3000 U植酸酶的基础饲料,Ⅲ组饲喂每千克添加4.5 g Ca(H2PO4)2的基础饲料,Ⅳ组饲喂每千克添加8.9 g Ca(H2PO4)2的基础饲料。结果显示:饲料中添加3000 U/kg和1500 U/kg植酸酶显著地促进了鲤鱼生长,降低了饲料系数,提高了饲料中磷的利用率。与对照组相比,3000 U/kg和1500 U/kg植酸酶组鲤鱼的增重率分别提高61.06%和52.81%,鲤鱼对饲料中磷的表观消化率分别提高65.63%和61.65%,粪磷含量分别下降24.58%和22.88%。本试验表明:植酸酶可以显著地促进鲤鱼的生长和提高磷的利用率。     

Effects of Restricted Feeding Regimes on Growth and Feed Utilization of Juvenile Gilthead Sea Bream, Sparus aurata

The effect of restricted feeding on growth, feed efficiency, and body composition was studied in juveniles of gilthead sea bream, Sparus aurata. Juveniles (6.4 g) were stocked into 12 tanks at a density of 16 fish per tank. Four different feeding schedules were tested on triplicate groups of juvenile fish: (1) control fed for 48 d without deprivation, (2) starvation for 1 d and then refed for 2 d (S1), (3) 50% satiation for 2 d and then refed to apparent satiation for 2 d (R2), and (4) 50% satiation for 6 d and then refed to apparent satiation for another 6 d (R6). Results indicated that all fish subjected to cycled restricted feeding regimes were unable to achieve catching up with control group. The specific growth rate of fish in the control was significantly higher than those in S1, R2, and R6, which were not significantly different from each other. Protein efficiency and protein productive value were significantly higher in R2 compared to control, S1, and R6. Fish in R2 had lowest feed conversion ratio (1.12) compared to the control (1.17). Body protein composition in R6 was less than that of the control, S1, and R2, while moisture, lipid, and ash content were not significantly different compared to the control.