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.     

紫海胆肠道真菌Aspergillus sp.HDf2产nonadride类次生代谢产物

[目的]对从紫海胆肠道分离得到的曲霉菌(Aspergillus sp.)菌株HDf2进行次生代谢产物研究.[方法]采用液体发酵,运用柱层析方法从培养液中分离、纯化单体化合物.[结果]从乙酸乙酯提取物较高极性段分离得到1个单体化合物,通过波谱解析和与文献对照将其鉴定为nonadride类化合物glauconic acid.[结论]该研究首次报道了海洋来源的真菌产天然界稀有的nonadride类天然化合物glauconic acido.     

Carotenoid composition of a New Zealand (Evechinus chloroticus) and an Australian (Heliocidaris erythrogramma) sea urchin in relation to gonad colour

Sea urchins are commercially harvested for their edible gonads, also known as roe or uni. Most species, particularly those from the Northern hemisphere are reported to exhibit limited variation in gonad colour, which is proposed to be due to carotenoid pigments. The commercially harvested species from New Zealand, Evechinus chloroticus, and from Australia, Heliocidaris erythrogramma, however, exhibit considerable gonad colour variation, ranging from a culinary desirable light yellow/orange to an undesirable brown. Gonads from E. chloroticus and H. erythrogramma were characterized spectrophotometrically and the carotenoid content extracted and analysed by reversed‐phase high‐performance liquid chromatography. The main carotenoid found in the gonads of both species was 9′‐cis‐echinenone, with lower levels of all‐trans‐echinenone, lutein and isozeaxanthin. Carotenoid composition contributed to the yellow/orange colour components of the gonads, but was not correlated with the darker roe coloration observed in some E. chloroticus individuals. Our results highlight important considerations relating sea urchin gonad coloration to carotenoid content and as such will provide useful information for the future aquaculture and processing of these two species.     

光照强度对紫海胆浮游幼体生长及消化酶活性的影响

本研究以紫海胆(Anthocidaris crassispina)为研究对象,通过水槽实验方法,模拟分析了自然光周期条件下光照强度对紫海胆浮游幼体生长、存活以及体内消化酶活性的影响,旨在为紫海胆苗种的规模化繁育提供必要的生物学参数。研究发现,在实验设计的光照强度梯度(0、500、1000、2000、3000 lx)内,光照强度对紫海胆浮游幼体的体长、躯干部骨针长度和口后腕骨针长度的影响趋势一致,影响程度由高到低为500 lx>0 lx>1000 lx>2000 lx>3000 lx。在500 lx条件下,紫海胆浮游幼体的体长、躯干部骨针长度和口后腕骨针长度都达到最高,且显著优于其他实验组(P<0.05),此时脂肪酶和淀粉酶活性最强;在2000 lx条件下,紫海胆的胃蛋白酶活性最强;在3000 lx条件下,紫海胆浮游幼体发育到11 d已全部死亡。研究表明,在500 lx光照强度下,紫海胆浮游幼体可保持最佳的生长速度、消化酶活性以及存活率,500 lx为紫海胆浮游幼体生长发育的最佳光照强度。     

紫海胆黄基本营养成分的分析与评价

为了测定紫海胆黄中的营养成分,并对其营养价值进行系统分析及合理评价,采用国家标准的生化测定方法以及美国化学分析方法(AOAC)检测海胆黄中的水分、粗灰分、粗蛋白质、粗脂肪、总糖、氨基酸、脂肪酸及矿物质。结果显示:海胆黄粉中水分含量(5.29±0.02)%,粗灰分(8.69±0.03)%,粗蛋白质(60.36±0.04)%,粗脂肪(25.32±0.09)%,总糖含量(0.044±0.002)mg/100 g;共检出18种氨基酸,总含量(46.50±0.89)%;谷氨酸含量最高,为(5.57±0.11)%;必须氨基酸占总氨基酸的(37.75±0.01)%;主要的限制氨基酸是色氨酸和亮氨酸;药效氨基酸占氨基酸总量的46.86%;蛋白质氨基酸评分(AAS)0.8,化学评分(CS)0.5;必需氨基酸指数(EAAI)为77.86;共检出30种脂肪酸,EPA(二十碳五烯酸)+DHA(二十二碳六烯酸)含量(2.43±005)%;海胆黄富含钾、磷、钠、镁、铁、锌等矿物质元素;常量元素中,磷元素含量最高,为(1 432.27±8.91)mg/100 g;微量元素中,锌元素含量最高,为(13.13±0.09)mg/100 g。研究表明,海胆黄中蛋白质含量丰富,氨基酸种类多、比例合理,脂质含量高且富含EPA、DHA等多不饱和脂肪酸,矿物质含量丰富。     

南方紫海胆人工育苗试验

南方天然紫海胆经过暂养后，注射KCl溶液催产，受精卵在25．4℃海水中受精、发育，经过60天后海阳莆长到5mm以上．共剥离稚海胆30万枚，再经过90天左右培育，获得2cm左右的海胆苗16万。     

南方紫海胆摄食习性的初步研究

采用实验生态学的方法研究了成体南方紫海胆(Anthocidaris crassispina)的摄食和活力情况。结果表明,紫海胆在5种海藻共存的情况下,对不同海藻类具有不同选择性,日摄食率有显著性差异,对琼枝麒麟菜(Betaphycus gelatinum)的嗜食性最高,其次为半叶马尾藻(Sargassum hemiphyllum)、石花菜(Gelidium amansii)、石莼(Ulva lactuca),对刺松藻(Codium fragile)的喜好性较差。紫海胆的摄食受水温、海藻种类和自身体质量的影响,在23~27℃时活力和摄食状态最佳,水温升高和降低均会显著抑制其摄食;成体紫海胆对石莼、半叶马尾藻和琼枝麒麟菜的日摄食率有显著差异;在最适摄食水温下,紫海胆日摄食率随体质量增加呈显著的指数下降趋势。     

紫海胆肠道放线菌Micromonospora sp．HDa2次生代谢产物的研究

采用常规色谱分离技术对分离自健康紫海胆肠道的稀有放线菌Micromonospora sp．HDa2发酵液的化学成分进行分离纯化,并以波谱技术确定化合物的结构。结果表明：从放线菌Micromonospora sp．HDa2的发酵液乙酸乙酯提取物中分离鉴定了6个已知结构的环二肽化合物．分别为环（苯丙-缬）二肽（1）、环（苯丙-亮）二肽（2）、环（苯丙-异亮）二肽（3）、环（苯丙-苯丙）二肽（4）、环（亮-亮）二肽（5）和环（亮-异亮）二肽（6）。对紫海胆肠道放线菌进行分离。结果发现以上化合物均是从Micromonospora属放线菌中发现的。     

紫海胆黄脂肪酸的气相色谱-质谱分析

为了了解紫海胆黄中脂肪酸的组成,采用Bligh-Dyer提取法对样品中脂肪油进行提取,甲酯化后利用气相色谱-质谱联用仪进行分析测定。结果发现,从紫海胆黄中共鉴定出14种脂肪酸,饱和脂肪酸6种,相对百分含量占总检出量的32.89%;不饱和脂肪酸8种,相对百分含量占总检出量的67.11%,其中,5,8,11,14,17-二十碳五烯酸(EPA)和4,7,10,13,16,19-二十二碳六烯酸(DHA)的相对百分含量分别为12.73%和1.21%。