口虾蛄人工育苗技术的研究

利用工厂化育苗设施,进行口虾蛄人工育苗的试验,共培育出全长1.6 cm的稚虾蛄约6万尾,平均出苗量为1万尾/m3。在此基础上,探讨了口虾蛄人工洞穴和幼体培育的技术要点。结果表明:现有的育苗设施能满足口虾蛄工厂化育苗的要求。同时,口虾蛄对底质、洞穴、水温、饵料等都有严格的要求。     

黑斑口虾蛄人工育苗技术研究

通过黑斑口虾蛄人工育苗试验。初步研究其生态习性、繁殖重演学及其幼体发育的特性。认为水温、环境稳定性及光周期是影响其抱卵孵化成功与否的主要因素,水温、光照、底质或人工洞穴、饵料是影响幼体谱态率及成活率高低的关键因子。黑斑口虾蛄的伪蚤状幼体生长过程可分为３个阶段：卵黄营养阶段、浮游变态率及成活率高低的关键因子。黑斑口虾蛄的伪蚤状幼体生长过程可分为３个阶段：卵黄营养阶段、浮游阶段及底栖阶段,仔虾蛄比底栖     

眼斑猛虾蛄幼体的发育

通过对眼斑猛虾蛄（Harpiosquilla annandalei）幼体各发育期的连续取样，在显微镜或解剖镜下系统地观察各发育期的形态变化及生长特征并描图。眼斑猛虾蛄假蚤状幼体经11次蜕皮，在水温24～27℃，盐度25．4～29．0的条件下，历时49d，发育变态成仔虾蛄；第Ⅰ期假蚤状幼体（Z1）体长1．75～1．83mm，头部有一长额角，头胸甲形状似龟壳，有1对腹侧齿，四角有刺，后部中间有一较长棘刺；第Ⅵ期头胸甲形状渐变成梯形，腹侧齿5对，第一触角中鞭萌芽，第二触角内肢发育呈短芽状，第Ⅷ期头胸甲左右两侧边缘开始渐向下弯卷；第Ⅺ期（Z11）体长15．10～17．20mm，第二触角内肢发育成鞭状且分为14～16节，尾肢外肢2节，内肢1节；Ⅰ期仔虾蛄体长14．50～16．10mm，长额角消失，头胸头形状仍为梯形，但光滑无腹侧齿，前侧角圆形，后侧角有二个缺角，这是该种的特征，后部中间棘刺消失，头胸甲占体长的比例明显缩小，形似成体虾蛄。眼斑猛虾蛄的幼体与黑斑口虾蛄的幼体的形态存在一定差异，主要表现在头胸甲与体长的比例，头胸甲的长宽比及第二触鳞片刚毛数和尾节的侧小齿、中间小齿和亚中间小齿的齿数。     

口虾蛄对人工洞穴选择性的初步研究

在室内水泥池模拟养殖池塘环境下,研究了口虾蛄对不同长度、直径、埋置方式的PVC管人工洞穴的选择性。试验结果:口虾蛄对直径为40 mm的人工洞穴的选择率最高,其次为直径50 mm的;在长度方面,口虾蛄较偏爱长度为40 cm和60 cm的人工洞穴,二者之间没有显著性差异(P0.05);在埋置方式上,口虾蛄对直插、斜插和混插模式人工洞穴的选择较均衡,三者间不存在显著性差异(P0.05)。结果表明,口虾蛄对人工洞穴的入穴率基本能达到80%以上,因此建议在口虾蛄实际养殖生产过程中放置人工洞穴,以提高其养殖产量。     

口虾蛄的繁殖行为

通过口虾蛄的室内人工繁殖试验,观察了口虾蛄亲虾的繁殖习性,包括亲虾的产卵和其护卵行为,并观察了其受精卵的孵化和幼体的出膜过程,初步探讨了口虾蛄有关苗种技术。     

乌龟养殖技术系列问答(四)

问：哪些介质可用作龟卵孵化？答：泥沙作为孵化介质，一是保温保湿和通气性能好；二是泥沙材料来源广，价格便宜。但泥沙作孵化介质，不便搬运。为减轻劳动强度，适应工厂化大批量生产，近年有些单位改用无毒人造海绵作为孵化介质。其方法是：用4～5cm的硬塑料板作为孵化箱的底板，在箱板上铺一层5cm的人造海绵，龟卵均匀放在上面，然后在龟印上盖一层湿的人造海绵，放入孵化室中孵化，在孵化过程中注意搞好控温、控湿。据试验，其孵化效果很好，是一种很有前途的孵化介质和孵化方法。问：龟卵装箱时要注意些什么？答：龟卵装箱孵化时，一…     

三种介质对黄喉拟水龟孵化率的影响

本文通过对黄喉拟水龟产卵的观察及利用细沙、泥沙、黄土三种介质进行龟卵孵化试验 ,表明黄喉拟水龟产卵时间集中于 5、 6月份 ,平均年产卵窝数为 2 0 5 ,受精率为 6 6 9% ,三种介质孵化天数 6 6～82d ,其平均孵化率分别为 2 5 34%、 6 5 34%、 78 6 6 % ,黄土在三种介质中为最优孵化介质。     

眼斑双锯鱼的人工繁育技术研究

在人工饲养条件下,模拟自然环境对野生眼斑双锯鱼Amphiprion ocellaris进行驯养使其达到性成熟、配对、产卵。显微镜下观察其胚胎发育的形态学变化。结果表明,眼斑双锯鱼的胚胎发育同大多数硬骨鱼类基本相似,属端黄卵盘状卵裂;在水温27.0±0.5℃条件下,经192～216h完成孵化;仔鱼在孵出的第2天开食轮虫,4～5d变态为稚鱼,开始投喂卤虫无节幼体,18～20d进入幼鱼期,45～50d开始投喂人工配合饵料及碎虾肉。     

南海北部陆架区虾蛄类的种类组成和数量分布

根据2006-2007年南海北部陆架区4个季节的调查资料,分析该海区虾蛄类的种类组成和数量分布。结果表明,虾蛄类有15种,隶属于4科7属。虾蛄类可以分为3种生态类群：热带生态类群、热带亚热带生态类群和广温性生态类群,并以热带亚热带类群为主。依据Pinkas等（1971）提出的相对重要性指数IRI判定,优势种为口虾蛄Oratosquilla oratoria、黑斑口虾蛄Oratosquilla kempi、猛虾姑Harpiosquilla harpax、长叉口虾蛄Oratosquilla nepa、棘突猛虾姑Harpiosquilla raphidea,它们属于虾蛄科和猛虾蛄科,其渔获率（1．86kg／h）占虾蛄类渔获率（1．90kg／h）的98．17％。经济虾蛄类为口虾蛄、黑斑口虾蛄、猛虾姑、长叉口虾蛄和装饰口虾蛄Oratosquilla ornata,它们属于虾蛄科和猛虾蛄科,其渔获率（1．84kg／h）占虾蛄类渔获率（1．90kg／h）的96．85％。虾蛄类平均生物量为42．18kg／km^2,经济虾蛄类平均生物量为40．85kg／km^2。虾蛄类的区域生物量分布：B断面最高（76．27kg／km^2）,A断面最低（25．13kg／km^2）;虾蛄类生物量的季节变化：秋季最高（49．24kg／km^2）,冬季最低（32．29kg／km^2）。虾蛄类的生物量分布与水深成负相关,密集分布于10～40m深的水域,尤以10m水深附近最多,达173．40kg／km^2,10m水深附近分布种类全属于经济种类。     

毛蚶在不同底质与撒播方式下潜沙行为的观测与分析

为了探究不同底质与撒播方式对毛蚶(Scapharca subcrenata)潜沙行为的影响,在实验室条件下,观察了壳长(10.0±0.9)mm毛蚶的潜沙过程,并研究了沙质(粒径251~500μm)和泥沙质(粒径120μm)两种底质和播散方式(集中和分散)对毛蚶潜沙时间和潜沙率的影响。结果显示,毛蚶潜沙过程分为准备、潜沙及结束3个阶段。在两种底质条件下,集中播撒方式的毛蚶潜沙时间均短于分散播撒方式,但同种底质不同播撒方式下的毛蚶潜沙时间差异不显著(P0.05)。无论是集中播撒还是分散播撒,沙质条件下毛蚶的潜沙时间均短于泥沙质的潜沙时间,并且在分散播撒方式下,两种底质的差异达到显著水平(P0.05);两种底质条件下,毛蚶的潜沙率均表现为集中播撒高于分散播撒。研究表明,与泥沙质底质相比,毛蚶在沙质条件下更易于快速潜底;与分散播散方式相比,集中播撒更利于毛蚶快速潜底。     

Method for efficiently obtaining fertilized eggs from the black scraper Thamnaconus modestus by natural spawning in captivity

To develop an efficient and stable method for enhancing spawning of black scrapers in captivity, we examined the following three factors: (1) different kinds of spawning substrate, (2) the area of the spawning substrate, (3) the grain size of the spawning substrate. The results demonstrated that sand is the optimum spawning substrate when compared to a hard polyvinyl chloride sheet, a piece of shading net, or artificial spawning grass. No difference was observed in the spawning frequency between a small sand bed of area 400?cm² and sand spread over the bottom of the tank to an area of 7085?cm², since the egg masses were spawned on the sand in a small area approximately 15?cm in diameter. In addition to the spawned eggs, the small movable sand bed is useful for subsequent harvest. No differences were observed in either the spawning frequency or the hatching rate when using sand beds with different grain sizes. In large-scale egg collection trials, an average of 33 egg masses from which an average of 403,000 larval fish were obtained. We can therefore conclude that the procedure developed in the present study is applicable to the commercial-scale seed production of black scraper.     

Seasonal Changes in the Milt Quality of Waigieu Seaperch,Psammoperca waigiensis: Implications for Artificial Propagation

Milt quality of Waigieu seaperch was sampled at the beginning, the middle, and the end of the spawning season to assess if the sampling season has an effect on milt quality parameters. The milt volume and total sperm production were higher at the middle of the spawning season while the sperm concentration in milt was significantly higher at the beginning and the end of the spawning season. Sperm morphology and the major parameters of seminal plasma (pH, total protein, Mg²⁺, or Ca²⁺ concentrations) did not differ throughout the spawning season. The concentrations of Na⁺ and the osmolality increased throughout the spawning season. The percentage of motile cells did not differ during the spawning season while the duration of sperm motility (swimming duration) and velocity (swimming speed) were significantly different during the spawning season. The fertilization rate (75.7 ± 6.8%) and hatching rate (56.5 ± 3.1%) at the middle of the spawning season were higher than at the beginning and end periods. Results indicated that milt quality parameters and fertility success in the middle of the spawning season were higher compared to earlier and later sampling dates. Thus, we recommend collecting milt during this time for maximal fertilization and hatching success.     

Effects of reproductive timing and hatch date on fathead minnow recruitment

Abstract –  Timing of reproduction can be an important determinant of recruitment success for fish in strongly seasonal environments, both for individuals hatching at different times over extended spawning seasons and for entire cohorts, if the spawning period is accelerated or delayed among years. To examine potential demographic consequences of delayed spawning, we staggered dates that fathead minnow ( Pimephales promelas ) were introduced into experimental ponds in Alberta, Canada, by 3 weeks and compared growth and survival of offspring from early- and late-stocked fish. By autumn, size and mass were consistently greater in early-hatched minnows, regardless of cohort density. Size differences between treatments persisted through the second summer, which likely contributed to a higher proportion of early-hatched fish reaching sexual maturity as yearlings compared with late-hatched counterparts. Because late spawning can limit growth and subsequent maturation of progeny, temporal variability in reproductive timing should be considered when assessing recruitment potential of new year-classes.     

Communal pair spawning behaviour of vendace (Coregonus albula) in the dark

Mating in nature is rarely random, and most fish species have refined mating systems. The vendace (Coregonus albula) is a short‐lived, small‐sized, cold‐water‐adapted pelagic schooling species that is known to spawn in groups, but the actual mating system of this species, like many other group‐spawning fishes, has not been described in detail. Vendace typically spawn in the littoral or sublittoral zones of lakes in late autumn, and the hatching of larvae occurs close to icebreak in the following spring. In our large study lake, vendace larvae were caught in 93% of 1,149 random sampling locations lake‐wide. We examined the courtship and mating of vendace under experimental conditions by nonintrusive observation of the natural behaviour, to clarify whether spawning activity is associated with illumination and to assess the postspawning mortality of vendace. Here, we describe and document in detail for the first time the spawning behaviour of vendace: they spawn in the dark, and females release a small portion of their eggs (on average 1% of mean total individual fecundity) when the female and male, side by side, dart from near the bottom up towards the surface, that is perform a spawning rise. Males and females had several spawning rises (on average 1,200). Our results showed high postspawning mortality (56%). The spawning stress seems to be a potential component of mortality regulating the lifespan duration of vendace.     

斑鳜人工繁殖技术初报

2011-2013年,利用野生和经人工驯养的野生斑鳜（ Siniperca scherzeri ）亲鱼进行人工繁殖试验。结果表明：采用地欧酮（ DOM）和促黄体素释放激素类似物（ LHRH -A3）组成的混合药物催产,在17．8-25．4℃水温条件下,斑鳜亲鱼群体的效应时间为24-46．5 h,存在产卵高峰期,产卵持续时间一般长达1-1．5 d。自然产卵高峰期的受精率较高,最高可达80%以上,早期和晚期的较低;而孵化率差异不大,最高可达86．7%。人工授精的受精率可达91．3%,孵化率可达89．3%。未经人工驯养的野生斑鳜亲鱼人工催产的受精率、孵化率都明显低于经人工驯养的。     

梯级开发对家鱼产卵场高低流量过程的影响

产卵场特有的水力条件是四大家鱼繁衍的重要因素,尤其是流量脉冲引发的流速上涨是刺激家鱼产卵、保证鱼卵孵化的关键水力因子;流域梯级开发改变了天然河道的流量脉冲过程,导致产卵场破碎萎缩、鱼苗锐减。为揭示梯级开发对湘江干流四大家鱼产卵场水力特征的影响机理,建立了湘江干流家鱼产卵场二维数值模型,模拟了梯级开发前后典型高低流量脉冲过程,分析梯级开发对鱼类产卵场的影响。结果表明,梯级开发后,水流结构复杂性减弱甚至消失,高、低流速脉冲过程变得“尖锐”,流速上涨时间缩短50%（高流量脉冲）和67%（低流量脉冲）,高流量过程的 “喜好流速”或“触发流速”基本消失,低流量过程大部分流速均低于“腰点流速”;对流速上涨过程中平均流速分级水域面积统计表明,低于“腰点流速”面积分别扩大至3.0倍（Q高）和3.2倍（Q低）,“感应流速”范围水域面积减少至天然情况的15.8%（Q高）和1.2%（Q低）,“触发流速”范围面积减小至天然情况的1.5%（Q高）和1.6%（Q低）,“喜好流速”范围面积减小至天然情况的2.0%（Q高）和3.1%（Q低）。研究结果可为鱼类资源保护和恢复等措施提供参考和依据。     

鮸鱼性腺发育人为调控技术研究

根据鮸鱼自然繁殖习性,模拟其自然繁殖生境,采用调控水温、光照,并结合注射生物激素,对舟山近海鮸鱼的性腺发育进行人为调控。试验结果表明:通过调控水温、光照周期和注射外源激素能使鮸鱼由原来在9~10月份产卵提前到6月份产卵;而仅调控水温只能提前至8月份产卵;仅调控光照或仅在春季注射激素,不会使鮸鱼提前产卵。经调控后6月份产出的卵其受精率、孵化率和畸形率与9~10月份相比差异不显著。同时对调控方法和对不同年龄亲鱼的调控结果进行了讨论。     

真蛸亲体培育、产卵及孵化试验

2005~2007年春、夏期间,在浙江南麂岛开展了真蛸亲体培育、产卵及孵化的试验研究。结果表明:亲蛸培育成活率为77.5%~95.5%,平均产卵率为68.0%~83.3%。不搭配雄体产卵率为65.0%,搭配一定比例的雄体后产卵率达92.5%,最高达100%。不同附卵器附卵效果以方形鲍鱼箱为最好,圆形鲍鱼皮桶次之,扇贝笼最差。在南麂海域暂养在网箱中的真蛸当水温上升到13.5℃以上时就开始有少量产卵,多数开始产卵在16.0℃左右,主要产卵期在4~6月。不同个体真蛸的产卵量变化很大,少者只有22 632粒,多者达170 684粒,平均102 665粒,平均每颗卵粒重量在1.670~2.207 mg之间,大小为长2.8~3.1 mm、宽0.915~0.950 mm。在水温13.5~28.0℃范围内,真蛸卵可以正常孵化,孵化率达60.0%~80.0%,超过28℃时孵化率明显下降。真蛸卵的孵化时间较长,至少需要20 d以上。孵化时间长短与水温关系密切,水温越高,孵化时间越短。孵化期间平均水温16.5℃,整个孵化时间长达47 d。当孵化期间平均水温为21.6℃时,从产卵到稚蛸出膜大致需要25 d左右。此外,还发现亲蛸护卵可以减少疾病,提高孵化率,本文也论述了有关其对疾病防治方面的探索。     

Effect of partial or total replacement of forage fish by a dry diet on the quality of reproduction in pikeperch, Sander lucioperca

The aim of this preliminary study was to evaluate the influence of different feeding regimes on the quality of reproduction in pikeperch. Three diets were tested: forage fish (FF), a commercial dry feed (DD) and a mix of both (FD).  The diets were given to fish throughout a complete reproductive cycle. During the spawning season, couples were injected with human chorionic gonadotropin (hCG) and let to spawn on nests. Proportion of running males, spawning and hatching success and larval quality (weight, length, body protein, total lipid, fatty acid and lipid class compositions and resistances to osmotic shock and starvation stress tests at hatching) were evaluated. The proportion of running male was lower in the DD group than in the FF and FD groups (54% for DD against 76–89% for FF and FD). In addition, 25%, 62.5% and 75% of injected couples gave spawning that hatched in DD, FF and FD groups respectively. Larval quality parameters were not significantly different between treatments. The results indicate that overall quality of reproduction was higher in FF and FD treatments than in DD. It suggests that the dry feed used was not totally adequate for pikeperch reproduction. Relations between breeder reproductive performances and the feed compositions are discussed.     

Tolerance of Penaeus monodon Fabricius embryos to ozonated seawater

The tolerance of Penaeus monodon embryos from five spawnings (families) to four different ozone doses in seawater [0.0, 0.5, 1.0 and 2.0 mg L⁻¹, measured by the residual oxidant concentration (ROC)] was examined when applied for three exposure times (1, 2 and 4 min) at three post‐spawning treatment times (25, 120 and 480 min post‐spawning). Ozone dose typically had a larger affect on embryo hatching than exposure time and the ozone dose × exposure time interaction for most combinations of family and post‐spawning treatment time. At ozone doses of 2.0 mg L⁻¹, embryos had lower hatchings than controls for all families at 25 and 120 min post‐spawning, and for several combinations of family and exposure time at 480 min post‐spawning. At ozone doses of 1.0 mg L⁻¹, the effect on embryo hatching was more varied between families and exposure times for the three post‐spawning treatment times, but typically embryos were less affected when exposed at later post‐spawning treatment times. Ozone doses of 0.5 mg L⁻¹ typically had minimal effects on hatching for all exposure times and post‐spawning treatment times. In summary, later‐stage P. monodon embryos typically tolerated ozone doses of up to 1.0 mg L⁻¹ in seawater for durations of up to 4 min.